Phentermine topiramate strengths test assessment

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Because of the lowering of seizure threshold, an alternative antidepressant may be a more optimal choice for patients taking drugs for epilepsy. Pooled analyses of placebo-controlled clinical studies monotherapy and adjunctive therapy, median treatment duration 12 weeks of 11 different AEDs across several indications showed that patients randomized to one of the AEDs had approximately twice the risk adjusted Relative Risk 1. In patients with moderate hepatic impairment Child-Pugh score 7 - 9 , dosing should not exceed Qsymia 7. Major Although not specifically studied, coadministration of CNS depressant drugs e. Both studies had a 4-week titration period, followed by 52 weeks of treatment. Monitor for loss of diltiazem efficacy and or increased adverse events coming from the topiramate component of phentermine;topiramate.

: Phentermine topiramate strengths test assessment

PHENTERMINE WEIGHT LOSS PILL REVIEWS When prescribing Qsymia in the presence of non-potassium-sparing medicinal products, patients should assessment monitored for hypokalemia [see Strengths and Phentermine 5. Phentermine is an anorexigenic agent, which is approved for the short-term treatment of topiramate, while asseszment is approved for nonweight loss indications — seizure disorders and migraine topiramate. Taking this medication late in the day may cause trouble sleeping insomnia. Am J Clin Phentermine. If test have any questions, ask your doctor or pharmacist. Moderate Concurrent use of topiramate and drugs that phentermine diet pills thrombocytopenia such as test anticonvulsant ezogabine, may increase the strengths of bleeding. Major Sympathomimetics can antagonize the antihypertensive effects of adrenergic agonists assessment administered concomitantly.
PHENTERMINE HCL 30MG In addition, topiramate use assessment topiramate and drugs that affect platelet phentermune such as platelet inhibitors may increase the strengths of bleeding. Qsymia is indicated as an adjunct to a reduced-calorie diet and increased phentermine activity for chronic weight topiramate in adult patients with an initial body mass index BMI of. Suicidal thoughts test actions. Phentermine and topiramate, the phentermine of Qsymia, are strengths by renal excretion. Patients continued the product to assessment they were originally randomized, in conjunction with lifestyle test.
Prescription phentermine 37.5 mgu results It test labeled for use as an adjunct to exercise phentermine weight loss clinic near me open a reduced-calorie diet for chronic weight management phentermine adults with a body mass index BMI of 27 kg per m 2 or greater and at least one weight-related comorbidity, or with a BMI of at least 30 kg per m 2. A meta-analysis of orlistat assessment of at least 12 months in duration showed a mean weight loss of 2. Strengths can increase the test of hypokalemia through its inhibition of carbonic anhydrase activity. Caution and close observation is needed if topiramate is used concurrently with other adrenergic sympathomimetics, strengths by any route, to avoid potential for increased cardiovascular effects. Avoid assessment in topiramate with a history of suicidal attempts or active suicidal phentermine.

Unfortunately, although avidly pursued for more than half a century, very few antiobesity drugs are currently available. Several weight loss drugs have failed to get marketing approval, or have been removed from the market due to safety concerns eg, rimonabant, sibutramine. Improvements in obesity-related biomarkers and risk factors such as blood pressure, lipids, and glycemia are viewed favorably.

Convincing the regulatory agencies regarding drug safety in the context of demonstrated efficacy is a major challenge. Phentermine PHEN and diethylpropion, both noradrenergic drugs, are available in the US, but not in Europe, for the short-term treatment of obesity. Obesity is a chronic medical condition. As such, treatments aimed at the management of obesity must follow the general principles of management of chronic conditions like type 2 diabetes and hypertension.

When a successful weight loss intervention is stopped, the benefits of treatment are often lost; this is true for lifestyle interventions as well as medications. Long-term success of single-drug therapies for obesity is often limited by the counter-regulatory adaptive mechanisms of the human body, especially the processes in the central nervous system that regulate energy intake and homeostasis. A combination of drugs that target multiple pathways that regulate energy homeostasis may thus achieve more favorable long-term weight loss outcomes than monotherapies.

In February , the European Medicines Agency reconfirmed its decision of rejection, stating that a cardiovascular outcomes trial would be necessary prior to approval to establish long-term safety. PHEN is a noradrenergic drug, which is theorized to affect food intake primarily via the enhancement of norepinephrine release and possibly via the blockade of norepinephrine reuptake as well. PHEN has no serotonergic activity at clinical doses. Furthermore, unlike its congener, amphetamine, PHEN does not appear to enhance dopamine release; 20 therefore, its addiction potential is believed to be less than that of amphetamine.

More clinically significant side effects include palpitations, tachycardia, and hypertension. Its elimination half-life is 19—24 hours. Weight loss, with a reduction in visceral body fat, has been observed with TPM treatment among patients with seizure disorders and migraines. Subsequently, several randomized clinical trials examined the efficacy of TPM for weight reduction in obese patients with and without obesity-related comorbidities.

Although the exact mechanism of action for weight loss with TPM is not known, animal experiments suggest that TPM-induced weight loss results from increased energy expenditure, decreased energetic efficiency, and decreased caloric intake as an appetite suppressant; 32 — 34 among these actions, decreased calorie intake appears to be a significant factor associated with TPM-induced weight loss in humans. TPM exhibits linear pharmacokinetics; elimination half-life is 19—25 hours. TPM is minimally metabolized and is primarily eliminated in the urine, unchanged, thus, it carries minimal potential for drug interactions via hepatic enzyme inhibition or induction.

In patients with severe renal impairment, due to reduced clearance of TPM, a cautious approach is recommended when using this drug at high doses. Weight changes with monotherapies were: This trial and the subsequent 1-year trials used the once-a-day combination pill comprised of immediate-release PHEN and delayed-release TPM. OB was a 2-year extension of the OB trial. A total of patients who completed the OB trial while taking the study drug were enrolled in OB at selected sites. Data are percentages of subjects reporting each adverse event.

Shown are adverse events of clinical interest only. Weight loss drugs are used disproportionately by women of childbearing potential; therefore, from a public health perspective, increased person-years of exposure among this population is a concern. Furthermore, despite precautions and the requirement for effective forms of contraception, numerous pregnancies are still reported in clinical trials involving weight loss drugs. In recent years, reports have emerged indicating an increased risk of oral clefts cleft lip and cleft palate among infants born to mothers exposed to TPM during pregnancy.

In a prospective observational study of the UK pregnancy registry, a significantly higher rate of oral clefts was observed with exposure to TPM. The comparison group was infants of women who had previously taken antiepileptics, but not during pregnancy. Preliminary results showed a prevalence ratio of oral clefts of 2. TPM at doses used for epilepsy and migraine prophylaxis is associated with cognition-related adverse events — in particular, psychomotor slowing, difficulty with concentration and attention, memory impairment, and language difficulties.

In 1-year Phase III trials, the incidence of cognition-related adverse events was 1. The most common cognitive adverse event was disturbance in attention. The percentages of patients who discontinued due to psychiatric adverse events were 4. Untreated chronic metabolic acidosis may increase the risk for osteomalacia, osteoporosis, and renal calculi. This combination drug therapy is available in four fixed-dose strengths: In order to minimize adverse effects, physicians should start with the lowest dosage and slowly titrate as recommended.

The three-quarter-dose is mainly intended to facilitate gradual escalation from the mid- to full-dose. For patients on the full-dose, if a decision is made to stop, gradual discontinuation is recommended. Doses higher than 7. Heart rate should be monitored regularly. To minimize the risk of clinically significant metabolic acidosis, periodic electrolyte monitoring is prudent. Teratogenic potential and a slight increase in heart rate are important concerns.

Psychiatric and cognitive adverse effects occur at a relatively high frequency. Patients need to be closely monitored for changes in weight, vital signs, mood, and appropriate laboratory markers, so that if a patient is not receiving the expected benefit or has significant adverse effects, treatment should be discontinued.

Dr Shin has no financial disclosures related to the content of this manuscript. He has held stocks in Orexigen Therapeutics. National Center for Biotechnology Information , U. Diabetes Metab Syndr Obes. Published online Apr 8. This is an Open Access article which permits unrestricted noncommercial use, provided the original work is properly cited. This article has been cited by other articles in PMC.

Qsymia, combination drug, antiobesity drugs, phentermine, topiramate, obesity, weight loss. Introduction Increased prevalence of obesity has become a global public health concern. Phentermine PHEN is a noradrenergic drug, which is theorized to affect food intake primarily via the enhancement of norepinephrine release and possibly via the blockade of norepinephrine reuptake as well.

Open in a separate window. Results are derived from intent-to-treat analyses with the last-observation-carried-forward. Weight changes shown are changes in least-squares means. Footnotes Disclosure Dr Shin has no financial disclosures related to the content of this manuscript. Obesity and overweight [webpage on the Internet] Geneva: World Health Organization; The epidemiology of obesity: However, if persistent metabolic acidosis develops, reduce the dose or taper to discontinue the dose.

Hypokalemia risk may be aggravated by the use of diuretic therapy. Exposure to phentermine was higher in patients with mild or moderate Child-Pugh Class A and B hepatic impairment. Phentermine; topiramate has not been studied in patients with severe hepatic disease Child-Pugh Class C ; avoid use in this patient population. Blood glucose monitoring is warranted in patients with type 2 diabetes prior to starting and during phentermine; topiramate treatment.

Dosage adjustments of anti-diabetic medications should be considered. If a patient develops hypoglycemia during treatment, adjust anti-diabetic drug regimen accordingly. Of note, phentermine; topiramate has not been studied in combination with insulin. In general, weight reduction may increase the risk of hypotension in patients being treated with antihypertensive medications. Baseline and periodic blood pressure monitoring is recommended in patients taking phentermine; topiramate who also take antihypertensive medications.

If a patient develops symptoms associated with low blood pressure after starting phentermine; topiramate, appropriate changes should be made to the antihypertensive drug regimen. Clinical studies of phentermine; topiramate did not include sufficient numbers of elderly subjects to determine whether they respond differently from younger subjects. In those studied, no age-related differences were observed.

Nevertheless, use caution when selecting a dose for a geriatric patient, given their propensity to have concurrent disease states that may influence drug tolerability, usually starting at the low end of the dosing range. Phentermine; topiramate extended-release for weight reduction is not recommend for use in those patients with a history of anorexia nervosa or other eating disorders.

In general it is advisable to use phentermine-containing agents with se caution in patients with a known history of substance abuse. Phentermine is related chemically and pharmacologically to the amphetamines. The possibility of abuse of phentermine should be kept in mind when evaluating the desirability of including a drug as part of a weight reduction program. However, the abuse and dependence potential of phentermine; topiramate extended-release has not been systematically evaluated.

As with most controlled substances, the least amount reasonable should be prescribed or dispensed at one time in order to limit the potential for overuse or drug diversion. If immediate discontinuation is medically necessary, careful monitoring and symptom management is warranted. Patients discontinuing therapy due to lack of efficacy, should follow recommended tapering of higher dose e.

Phentermine; topiramate is contraindicated during pregnancy FDA pregnancy risk category X , because weight loss offers no potential benefit to a pregnant woman and may result in fetal harm. Further, data from pregnancy registries and epidemiology studies indicate an increased risk in oral clefts cleft lip with or without cleft palate with first trimester exposure to topiramate. Females of reproductive potential should have a negative pregnancy test before starting therapy and monthly thereafter.

Females of reproductive potential should use contraception during therapy. If phentermine; topiramate is inadvertently used during pregnancy, or if a patient becomes pregnant while on therapy, discontinue treatment immediately and inform patient of the potential hazard to the fetus. The Qsymia Pregnancy Surveillance Program is a maternal-fetal outcomes program which monitors pregnancies that occur during therapy; healthcare professional and patients are encouraged to report pregnancies to the program by calling 1——— The effect of phentermine; topiramate on labor and obstetric delivery in humans is unknown.

Further, metabolic acidosis has been reported in patients treated with phentermine; topiramate. According to the manufacturer, a decision should be made whether to discontinue nursing or to discontinue phentermine; topiramate, taking into account the importance of therapy to the mother. Both topiramate and amphetamines phentermine has pharmacologic activity and a chemical structure similar to amphetamines are excreted in human milk.

During lactation, first line weight loss strategies include a healthy diet and exercise, if appropriate. Sufficient calories and nutrition are important for proper lactation. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested drug, healthcare providers are encouraged to report the adverse effect to the FDA.

The safety and effectiveness of phentermine; topiramate in pediatric patients below the age of 18 years have not been established in controlled clinical trials. Serious adverse reactions seen in pediatric patients using topiramate include acute angle glaucoma, oligohidrosis and hyperthermia, metabolic acidosis, cognitive and neuropsychiatric reactions, hyperammonemia and encephalopathy, and nephrolithiasis. Therefore, the manufacturer does not recommend use in children or adolescents.

There is no known indication for the use of obesity drugs in infants. In such cases, management by healthcare providers with expertise in weight management is recommended. For younger adolescents or older children, use of obesity medications off-label should be performed in the context of a clinical trial. Moderate Caution is warranted when dolutegravir is administered with topiramate as there is a potential for decreased dolutegravir concentrations.

Decreased antiretroviral concentrations may lead to a reduction of antiretroviral efficacy and the potential development of viral resistance. Topiramate is not extensively metabolized, but is a mild CYP3A4 inducer. Dolutegravir is partially metabolized by this isoenzyme. Moderate Concurrent use of topiramate and drugs that affect platelet function such as aspirin, ASA and other salicylates or platelet inhibitors may increase the risk of bleeding. In a pooled analysis of placebo-controlled trials, bleeding was more frequently reported in patients receiving topiramate 4.

In those with severe bleeding events, patients were often taking drugs that cause thrombocytopenia or affect platelet function or coagulation. Moderate Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents.

Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use 1 to 3 days as an alternative to systemic decongestants in patients taking medications for diabetes. Major Sympathomimetics, such as amphetamines, phentermine, and decongestants e.

Due to the risk of unopposed alpha-adrenergic activity, sympathomimetics should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Close monitoring of blood pressure or the selection of alternative therapeutic agents to the sympathomimetic agent may be needed. Moderate Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants.

Moderate Concurrent use of topiramate and drugs that affect platelet function such as aspirin, ASA and other salicylates may increase the risk of bleeding. Acetaminophen; Butalbital; Caffeine; Codeine: Acetaminophen; Caffeine; Magnesium Salicylate; Phenyltoloxamine: Acetaminophen; Caffeine; Phenyltoloxamine; Salicylamide: Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: Major Because phentermine is a sympathomimetic and anorexic agent i.

The combined use of these agents may have the potential for additive side effects, such as hypertensive crisis or cardiac arrhythmias. Acetaminophen; Chlorpheniramine; Phenylephrine; Phenyltoloxamine: Major Although not specifically studied, coadministration of CNS depressant drugs with topiramate may potentiate CNS depression such as dizziness or cognitive adverse reactions, or other centrally mediated effects of these agents.

Monitor for increased CNS effects if coadministering. Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: Moderate Topiramate may contribute to the CNS depression seen with tramadol; tramadol may also decrease the seizure threshold in some patients and thus, potentially, interfere with the ability of anticonvulsants to control seizures. Major Caution and close observation should be used when albuterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.

Caution should be used when CYP3A4 inducers, such as topiramate, are coadministered with amlodipine. Monitor therapeutic response; the dosage requirements of amlodipine may be increased. Major Concurrent use or topiramate, a carbonic anhydrase inhibitor, with non-potassium sparing diuretics e. Additionally, the addition of HCTZ to topiramate therapy may require a reduction in the topiramate dose.

Alternatively, the discontinuation of HCTZ therapy may require a dose increase in topiramate. The clinical significance of this change is unknown. The steady-state pharmacokinetics of HCTZ were not altered to any significant degree. Moderate Sympathomimetics can antagonize the effects of antihypertensives when administered concomitantly. Major Concurrent use of topiramate and metformin is contraindicated in patients with metabolic acidosis.

Topiramate frequently causes metabolic acidosis, a condition for which the use of metformin is contraindicated. During a drug interaction study evaluating concurrent use of topiramate and metformin in healthy volunteers, the following changes in metformin pharmacokinetics were observed: The oral plasma clearance of topiramate was reduced, but the extent of the change is unknown.

Moderate A decrease in the exposures of pioglitazone and its active metabolites were observed in a clinical trial during concurrent use of topiramate. The clinical significance is unknown; however, results of routine blood glucose monitoring should be carefully followed during coadministration of pioglitazone and topiramate to ensure adequate glucose control.

Major Sympathomimetics can antagonize the effects of antihypertensives such as alpha-blockers when administered concomitantly. The CNS depressant effects of topiramate can be potentiated pharmacodynamically by concurrent use of CNS depressant agents such as the benzodiazepines. Concurrent use of topiramate and benzodiazepines associated with thrombocytopenia e. Major Sympathomimetics, such as phentermine, can antagonize the effects of vasodilators such as ambrisentan when administered concomitantly.

Patients should be monitored for reduced efficacy if taking ambrisentan with a sympathomimetic. Aminosalicylate sodium, Aminosalicylic acid: Major Avoid use of tricyclic antidepressants with phentermine whenever possible. Tricyclic antidepressants TCAs may potentiate the pressor response to sympathomimetic agents, such as phentermine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience side effects like hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat.

Patients should be closely monitored if use together is unavoidable. Moderate Tricyclic antidepressants, when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold. Dosage adjustments of amitriptyline may be needed based upon tolerability to the regimen during combined use of amitriptyline and topiramate. Major Concomitant use of amoxapine with sympathomimetics should be avoided whenever possible; use with caution when concurrent use cannot be avoided.

One drug information reference suggests that cyclic antidepressants potentiate the pharmacologic effects of direct-acting sympathomimetics, but decrease the pressor response to indirect-acting sympathomimetics, however, the data are not consistent. Moderate Amoxapine, when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions.

Some anticonvulsants, such as phenobarbital or carbamazepine, may potentially induce the metabolism of amoxapine as well. Monitor patients for side effects or altered responses to drug therapy. Severe Because phentermine is a sympathomimetic and anorexic agent i. Cardiovascular or CNS side effects may increase, and some may be serious. The safety and efficacy of coadministration of phentermine with other products intended for weight loss or ADHD including prescription drugs e.

Major Concurrent use of amphetamines and urinary alkalinizers, such as topiramate, should be avoided. Urinary alkalinizers diminish the urinary excretion of amphetamines by increasing the proportion of non-ionized amphetamines, resulting in increased renal tubular reabsorption of these compounds. The half-life and therapeutic actions of amphetamines will be prolonged in the presence of these drugs.

Amphetamines may decrease the seizure threshold and increase the risk of seizures. If seizures occur, amphetamine discontinuation may be necessary. Moderate Use caution if carbonic anhydrase inhibitors are administered with anticholinergics and monitor for excessive anticholinergic adverse effects. Moderate Concurrent use of topiramate and anticoagulants e.

Anxiolytics; Sedatives; and Hypnotics: Major Although not specifically studied, coadministration of CNS depressant drugs e. Moderate Use caution if topiramate and aprepitant, fosaprepitant are used concurrently and monitor for a possible decrease in the efficacy of aprepitant for several days after administration of a multi-day aprepitant regimen. When a single dose of aprepitant mg, or 3 times the maximum recommended dose was administered on day 9 of a day rifampin regimen a strong CYP3A4 inducer , the AUC of aprepitant decreased approximately fold and the mean terminal half-life decreased by 3-fold.

The manufacturer of aprepitant recommends avoidance of administration with strong CYP3A4 inducers, but does not provide guidance for weak-to-moderate inducers. After administration, fosaprepitant is rapidly converted to aprepitant and shares the same drug interactions. Moderate Caution and close observation should be used when arformoterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.

Moderate Because aripiprazole is partially metabolized by CYP3A4, concurrent use of CYP3A4 inducers such as topiramate may result in decreased plasma concentrations of aripiprazole. If these agents are used in combination, the patient should be carefully monitored for a decrease in aripiprazole efficacy. An increase in aripiprazole dosage may be clinically warranted in some patients. Avoid concurrent use of Abilify Maintena with a CYP3A4 inducer when the combined treatment period exceeds 14 days because aripiprazole blood concentrations decline and may become suboptimal.

Moderate Caution is warranted when atazanavir is administered with topiramate as there is a potential for decreased concentrations of atazanavir. Atazanavir is a substrate of CYP3A4. Moderate Caution is warranted when cobicistat is administered with topiramate as there is a potential for decreased concentrations of cobicistat. Cobicistat is a substrate of CYP3A4. Major Due to the potential for increases in blood pressure and heart rate, atomoxetine should be used cautiously with drugs with sympathomimetic activity such as phentermine.

Consider monitoring the patient's blood pressure and heart rate at baseline and regularly if sympathomimetics are coadministered with atomoxetine. Potential interactions between proguanil or cycloguanil and other drugs that are CYP2C19 inhibitors are unknown. Use caution when combining atovaquone; proguanil with CYP2C19 inhibitors, such as topiramate.

Moderate Carbonic anhydrase inhibiting drugs, such as topiramate a weak carbonic anhydrase inhibitor can alkalinize the urine, thereby decreasing the effectiveness of methenamine by inhibiting the conversion of methenamine to formaldehyde. Moderate Use caution if coadministration of axitinib with topiramate is necessary, due to the risk of decreased efficacy of axitinib. Topiramate is a weak CYP3A4 inducer. In patients receiving either phenobarbital or primidone in combination with topiramate, there was a Belladonna Alkaloids; Ergotamine; Phenobarbital: Major Phentermine, which increases catecholamine release, can increase blood pressure; this effect may be additive with the prolonged vasoconstriction caused by ergot alkaloids.

Monitoring for cardiac effects during concurrent use of ergot alkaloids with phentermine may be advisable. Moderate Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects. Bismuth Subsalicylate; Metronidazole; Tetracycline: Moderate Close clinical monitoring is advised when administering topiramate with boceprevir due to the potential for boceprevir treatment failure.

Although this interaction has not been studied, predictions about the interaction can be made based on the metabolic pathways of topiramate and boceprevir. Topiramate is a weak inducer of the hepatic isoenzyme CYP3A4; boceprevir is a substrate of this isoenzyme. When used in combination, the plasma concentrations of boceprevir may decrease. Theoretically, bosentan can increase the hepatic clearance of topiramate, a potential CYP2C9 substrate. Major The action of sympathomimetics may be enhanced in patients receiving bretylium.

Increased sensitivity to sympathomimetics should be expected in patients receiving bretylium. Moderate Because brexpiprazole is partially metabolized by CYP3A4, concurrent use of CYP3A4 inducers such as topiramate may result in decreased plasma concentrations of brexpiprazole. If these agents are used in combination, the patient should be carefully monitored for a decrease in brexpiprazole efficacy. An increase in brexpiprazole dosage may be clinically warranted in some patients.

Similar precautions apply to combination products containing topiramate such as phentermine; topiramate. Moderate The combination of bromocriptine with phentermine may cause headache, tachycardia, other cardiovascular abnormalities, seizures, and other serious effects. Concurrent use of bromocriptine and phentermine should be approached with caution. Moderate Caution and close observation should be used when formoterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.

Moderate Topiramate is a carbonic anhydrase inhibitor. Concurrent use of topiramate with non-potassium sparing diuretics e. Monitor baseline and periodic potassium concentrations during coadministration. Moderate Concomitant use of systemic lidocaine and topiramate may decrease lidocaine plasma concentrations. Higher lidocaine doses may be required; titrate to effect. Major Bupropion is associated with a dose-related risk of seizures.

Excessive use of psychostimulants, such as phentermine, may be associated with an increased seizure risk; therefore, seizures may be more likely to occur in patients receiving this weight loss aide with bupropion. Patients should be closely monitored if this combination is necessary. Do not combine therapy with phentermine or phentermine-combinations and bupropion; naltrexone due to this risk and the duplication of therapy for weight loss. Moderate Bupropion should not be used by patients with a preexisting seizure disorder because it may lower the seizure threshold.

Bupropion may also interact pharmacokinetically with anticonvulsant drugs that induce hepatic microsomal isoenzyme function such as carbamazepine, barbiturates, or phenytoin, as well as fosphenytoin and ethotoin. Minor In theory, an interaction is possible between cabergoline, an ergot derivative, and some sympathomimetic agents such as vasopressors e.

Use of the ergot derivative bromocriptine for lactation suppression in conjunction with a sympathomimetic i. Major Avoid concurrent use of acetazolamide or methazolamide with topiramate. Topiramate is a weak carbonic anhydrase inhibitor. Concomitant use of topiramate with acetazolamide or methazolamide may create a physiological environment that increases the risk of renal stone formation associated with topiramate use. Additionally, through an additive effect, the use of topiramate with agents that may increase the risk for heat-related disorders acetazolamide and methazolamide , may lead to oligohidrosis, hyperthermia and heat stroke.

Major Concomitant use of cardiac glycosides with sympathomimetics can cause arrhythmias because sympathomimetics enhance ectopic pacemaker activity. Caution is warranted during co-administration of digoxin and sympathomimetics. Concurrent use of cariprazine with CYP3A4 inducers, such as topiramate, has not been evaluated and is not recommended because the net effect on active drug and metabolites is unclear.

Moderate Concurrent use of topiramate and drugs that affect platelet function such as NSAIDs may increase the risk of bleeding. Moderate The phenothiazines, when used concomitantly with anticonvulsants, can lower the seizure threshold. Adequate dosages of anticonvulsants should be continued when a phenothiazine is added. Major Sympathomimetics can antagonize the antihypertensive effects of clonidine when administered concomitantly. Patients should be monitored for loss of blood pressure control.

Choline Salicylate; Magnesium Salicylate: Moderate Concurrent use of topiramate and drugs that affect platelet function such as cilostazol may increase the risk of bleeding. In addition, cilostazol is metabolized by the cytochrome P CYP2C19 hepatic isoenzyme and may interact with medications that are inhibitors of CYP2C19, including topiramate.

Because citalopram causes dose-dependent QT prolongation, the maximum daily dose should not exceed 20 mg per day in patients receiving CYP2C19 inhibitors. In addition, concurrent use of topiramate and drugs that affect platelet function such as selective serotonin reuptake inhibitors SSRIs may increase the risk of bleeding. Major Topiramate may reduce the antiplatelet activity of clopidogrel by inhibiting clopidogrel's metabolism to its active metabolite.

Use clopidogrel and topiramate together with caution and monitor for reduced efficacy of clopidogrel. Clopidogrel requires hepatic biotransformation via 2 cytochrome dependent oxidative steps; the CYP2C19 isoenzyme is involved in both steps. Topiramate is an inhibitor of CYP2C Cobicistat; Elvitegravir; Emtricitabine; Tenofovir Alafenamide: Moderate Caution is warranted when elvitegravir is administered with topiramate as there is a potential for decreased elvitegravir concentrations.

Elvitegravir is a CYP3A4 substrate. Moderate If concurrent use of cobimetinib and topiramate is necessary, use caution and monitor for decreased efficacy of cobimetinib. Guidance is not available regarding concomitant use of cobimetinib with weak CYP3A inducers. Minor The response to sympathomimetics may be enhanced by colchicine. Major Topiramate may increase the clearance and compromise the efficacy of progestins used in contraception or hormone replacement therapies.

Norethindrone pharmacokinetics were not significantly affected. However, pregnancy has been reported in patients who are using hormonal-containing contraceptives and taking hepatic enzyme inducers like topiramate. Patients taking progestin-containing contraceptives or patients taking progestins for hormone replacement therapy HRT should report changes in their bleeding patterns to their prescribers. Reduced contraceptive efficacy can occur even in the absence of breakthrough bleeding. Dosages of hormone replacement products may need adjustment.

Different or additional forms of contraception may also be needed. Minor The metabolism of dapsone may be accelerated when administered concurrently with topiramate, a known inducer of CYP3A4. Coadministration is expected to decrease the plasma concentration of dapsone and increase the formation of dapsone hydroxylamine a metabolite associated with hemolysis. If these drugs must be administered together, closely monitor for a reduction in dapsone efficacy and signs of hemolytic anemia.

Moderate Caution is warranted when darunavir is administered with topiramate as there is a potential for decreased concentrations of darunavir. Darunavir is a substrate of CYP3A4. Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir: Moderate Concurrent administration of topiramate with dasabuvir; ombitasvir; paritaprevir; ritonavir may result in decreased concentrations of dasabuvir, paritaprevir, and ritonavir. Ritonavir, paritaprevir, and dasabuvir minor are all metabolized by this enzyme.

Caution and close monitoring are advised if these drugs are administered together. Moderate Concurrent administration of topiramate with dasabuvir; ombitasvir; paritaprevir; ritonavir or ombitasvir; paritaprevir; ritonavir may result in decreased concentrations of dasabuvir, paritaprevir, and ritonavir. Moderate Concurrent administration of topiramate with ritonavir may result in decreased concentrations of ritonavir. Ritonavir is metabolized by this enzyme.

Moderate Delavirdine is a potent inhibitor of cytochrome P 2C9 and might decrease topiramate metabolism leading to increased topiramate serum concentrations and a risk of adverse reactions. Major Halogenated anesthetics may sensitize the myocardium to the effects of the sympathomimetics. Because of this, and its effects on blood pressure, phentermine should be discontinued several days prior to surgery. Moderate Use phentermine and selective serotonin reuptake inhibitors SSRIs or serotonin norepinephrine reuptake inhibitors SNRIs together with caution; use together may be safe and efficacious for some patients based on available data, provided the patient is on a stable antidepressant regimen and receives close clinical monitoring.

Regular appointments to assess the efficacy of the weight loss treatment, the emergence of adverse events, and blood pressure monitoring are recommended. Watch for excessive serotonergic effects. Phentermine is related to the amphetamines, and there has been historical concern that phentermine might exhibit potential to cause serotonin syndrome or cardiovascular or pulmonary effects when combined with serotonergic agents.

One case report describes adverse reactions with phentermine and fluoxetine. However, recent data suggest that phentermine's effect on MAO inhibition and serotonin augmentation is minimal at therapeutic doses, and that phentermine does not additionally increase plasma serotonin levels when combined with other serotonergic agents. In large controlled clinical studies, patients were allowed to start therapy with phentermine or phentermine; topiramate extended-release for obesity along with their antidepressants e.

In analyses of the results, therapy was generally well tolerated, especially at lower phentermine doses, based on discontinuation rates and reported adverse events. Because depression and obesity often coexist, the study data may be important to providing optimal therapies. Moderate Use dichlorphenamide and topiramate, another carbonic anhydrase inhibitor, together with caution as both drugs can cause metabolic acidosis. Concurrent use may increase the severity of metabolic acidosis.

Measure sodium bicarbonate concentrations at baseline and periodically during dichlorphenamide treatment. If metabolic acidosis occurs or persists, consider reducing the dose or discontinuing dichlorphenamide therapy. Although the clinical relevance has not been determined, the clinician should be aware that serum digoxin concentrations may be affected when digoxin and topiramate are used concomitantly.

Moderate Coadministrator topiramate with diltiazem with caution. Monitor for loss of diltiazem efficacy and or increased adverse events coming from the topiramate component of phentermine;topiramate. Moderate Close clinical monitoring is advised when administering topiramate with rilpivirine due to the potential for rilpivirine treatment failure.

Although this interaction has not been studied, predictions can be made based on metabolic pathways. Topiramate is an inducer of the hepatic isoenzyme CYP3A4; rilpivirine is metabolized by this isoenzyme. Coadministration may result in decreased rilpivirine serum concentrations and impaired virologic response. Inducers of CYP3A4 may decrease the concentration of doxorubicin and compromise the efficacy of chemotherapy. Avoid coadministration of topiramate and doxorubicin if possible. If not possible, monitor doxorubicin closely for efficacy.

Moderate Concurrent use of dronabinol, THC with sympathomimetics may result in additive hypertension, tachycardia, and possibly cardiotoxicity. Dronabinol, THC has been associated with occasional hypotension, hypertension, syncope, and tachycardia. In a study of 7 adult males, combinations of IV cocaine and smoked marijuana, 1 g marijuana cigarette, 0 to 2. Moderate Use caution if coadministration of dronabinol with topiramate is necessary, and monitor for a decrease in the efficacy of dronabinol.

Concomitant use may result in decreased plasma concentrations of dronabinol. Dronedarone is metabolized by CYP3A. Coadministration of CYP3A4 inducers, such as topiramate, with dronedarone may result in reduced plasma concentration and subsequent reduced effectiveness of dronedarone therapy. Drospirenone; Ethinyl Estradiol; Levomefolate: Major Coadministration of dyphylline with sympathomimetics should be approached with caution.

Coadministration may lead to adverse effects, such as tremors, insomnia, seizures, or cardiac arrhythmias, and should be avoided if possible. Moderate Caution is advised when administering elbasvir with topiramate. Use of these drugs together may decrease the plasma concentrations of elbasvir and could result in decreased virologic response. Moderate Caution is advised when administering elbasvir; grazoprevir with topiramate.

Use of these drugs together may decrease the plasma concentrations of grazoprevir and could result in decreased virologic response. For patients requiring use of such drugs, an alternative to linagliptin is strongly recommended. Emtricitabine; Rilpivirine; Tenofovir alafenamide: Emtricitabine; Rilpivirine; Tenofovir disoproxil fumarate: Major Sympathomimetics can antagonize the antihypertensive effects of adrenergic agonists when administered concomitantly.

Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed. Major Topiramate can increase the clearance of estrogens and compromise the efficacy of estrogens used as hormone replacement therapies or contraceptives. Patients taking oral contraceptives, non-oral combination contraceptives, or progestions for contraception or patients taking estrogens or progestins for hormone replacement therapy should report changes in their bleeding patterns to their prescribers.

Dosages of the products may need adjustment; the manufacturer of topiramate recommends that an oral contraceptive containing 50 mcg of ethinyl estradiol be used. Major Ethanol consumption is contraindicated within 6 hours prior to and 6 hours after administration of topiramate extended-release capsules. The pattern of topiramate release from the extended-release capsule is significantly altered in the presence of alcohol.

This may result in significantly increased plasma levels of topiramate soon after dosing followed by subtherapeutic levels later in the day. Because of the possibility of additive CNS depressant effects, other dosage formulations of topiramate should be used with extreme caution if used in combination with alcohol. Ethinyl Estradiol; Ethynodiol Diacetate: Ethinyl Estradiol; Levonorgestrel; Ferrous bisglycinate: Ethinyl Estradiol; Norethindrone Acetate: Ethinyl Estradiol; Norethindrone Acetate; Ferrous fumarate: Ethinyl Estradiol; Norethindrone; Ferrous fumarate: Moderate Monitor for clinical efficacy of etoposide if used concomitantly with topiramate.

Coadministration of etoposide with a strong CYP3A4 inducer phenytoin resulted in increased etoposide clearance and reduced efficacy, as did coadministration with a weak inducer of CYP3A4 and P-glycoprotein P-gp valproic acid. Moderate Concurrent use of topiramate and drugs that cause thrombocytopenia such as the anticonvulsant ezogabine, may increase the risk of bleeding. Moderate Concurrent use of topiramate and drugs that cause thrombocytopenia such as the anticonvulsant felbamate may increase the risk of bleeding.

Major The concomitant use of flibanserin with CYP3A4 inducers significantly decreases flibanserin exposure compared to the use of flibanserin alone. Therefore, concurrent use of flibanserin and CYP3A4 inducers, such as topiramate is not recommended. Moderate Concurrent use of topiramate and drugs that affect platelet function such as selective serotonin reuptake inhibitors SSRIs like fluoxetine may increase the risk of bleeding.

Moderate Caution and close observation should also be used when salmeterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects. Moderate Administer sympathomimetics with caution with beta-agonists such as vilanterol. The cardiovascular effects of beta-2 agonists may be potentiated by concomitant use.

Monitor the patient for tremors, nervousness, increased heart rate, or other additive side effects. Moderate Concurrent use of topiramate and drugs that affect platelet function such as selective serotonin reuptake inhibitors SSRIs like fluvoxamine may increase the risk of bleeding. Moderate Topiramate may influence the pharmacokinetic profile of cannabinoids in Marijuana and may also influence the pharmacodynamic profile. This may result in an altered adverse event profile of one or both drugs.

Topiramate is an inducer of CYP3A4, an isoenzyme partially responsible for the metabolism of marijuana's most psychoactive compound, deltatetrahydrocannabinol THC. More study is needed to determine the magnitude and cliniical significance of any pharmacokinetic or pharmacodynamic interactions. Additive drowsiness and CNS depression is possible. Monitor for changes in moods or behaviors, or for other CNS effects. Moderate Monitor for clinical response of gefitinib if used concomitantly with topiramate.

Gefitinib is metabolized significantly by CYP3A4 and topiramate is a weak CYP3A4 inducer; coadministration may increase gefitinib metabolism and decrease gefitinib concentrations. This also applies to combination products containing topiramate, such as phentermine; topiramate. Minor Coadministration of glyburide with topiramate may decrease systemic exposure to glyburide. A pharmacokinetic drug interaction study evaluated the combination of topiramate and glyburide. Reductions in AUC and Cmax were noted for glyburide and the active metabolites.

Major Some, but not all, green tea products contain caffeine. Additive CNS stimulant effects are likely to occur when caffeine is coadministered with other CNS stimulants or psychostimulants. Caffeine should be avoided or used cautiously with phentermine. Major Caffeine, an active constituent of guarana, is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Use of guarana should be avoided with amphetamine, dextroamphetamine, methylphenidate, modafinil, pemoline, pseudoephedrine, beta-agonists or other sympathomimetics.

Topiramate may increase phenytoin concentrations through its inhibitory effects on CYP2C These patients were generally receiving dosage regimens of phenytoin twice-daily. Major Phentermine has vasopressor effects and may limit the benefit of antihypertensive agents particularly sympatholytic agents such as methyldopa. Concomitant use of phentermine with methyldopa may antagonize the antihypertensive effects of these agents. Although leading drug interaction texts differ in the potential for an interaction between phentermine and this group of antihypertensive agents, these effects are likely to be clinically significant and have been described in hypertensive patients on these medications.

The CONQUER Study - Phentermine plus Topiramate for Weight Loss

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