Phentermine/topiramate

What is Phentermine/topiramate?

• Phentermine/topiramate (Qsymia) is a combination of phentermine, a sympathomimetic amine anorectic, and topiramate extended-release, an antiepileptic drug.

Phentermine and topiramate

What are the uses of this medicine?

• Qsymia is a prescription medicine that contains phentermine and topiramate extended-release that may help some obese adults or some overweight adults who also have weight-related medical problems lose weight and keep the weight off.
• Qsymia should be used with a reduced calorie diet and increased physical activity.

Limitations of Use:

• It is not known if Qsymia changes your risk of heart problems or stroke or of death due to heart problems or stroke.
• It is not known if Qsymia is safe and effective when taken with other prescription and over-the-counter medicines, or herbal weight loss products.
• It is not known if Qsymia is safe and effective in children under 18 years old.

How does this medicine work?

• Phentermine is a sympathomimetic amine with pharmacologic activity similar to the prototype drugs of this class used in obesity, amphetamine (d- and d/l-amphetamine).
• Drugs of this class used in obesity are commonly known as "anorectics" or "anorexigenics."
• The effect of phentermine on chronic weight management is likely mediated by release of catecholamines in the hypothalamus, resulting in reduced appetite and decreased food consumption, but other metabolic effects may also be involved. The exact mechanism of action is not known.
• The precise mechanism of action of topiramate on chronic weight management is not known.
• Topiramate's effect on chronic weight management may be due to its effects on both appetite suppression and satiety enhancement, induced by a combination of pharmacologic effects including augmenting the activity of the neurotransmitter gamma-aminobutyrate, modulation of voltage-gated ion channels, inhibition of AMPA/kainite excitatory glutamate receptors, or inhibition of carbonic anhydrase.

Who Should Not Use this medicine ?

This medicine cannot be used in patients with:

• Pregnancy
• Glaucoma
• Hyperthyroidism
• During or within 14 days following the administration of monoamine oxidase inhibitors
• Known hypersensitivity or idiosyncrasy to the sympathomimetic amines

What drug interactions can this medicine cause?

• Use of phentermine is contraindicated during or within 14 days following the administration of monoamine oxidase inhibitors because of the risk of hypertensive crisis.
• Co-administration of multiple-dose Qsymia 15 mg/92 mg once daily with a single dose of oral contraceptive containing 35 µg ethinyl estradiol (estrogen component) and 1 mg norethindrone (progestin component) is not recommended.
• Qsymia is used with alcohol or other CNS depressants, the patient should be counseled regarding possible increased risk of CNS depression or side effects.
• Concurrent use of Qsymia with non-potassium sparing diuretics may potentiate the potassium-wasting action of these diuretics.

Is this medicine FDA approved?

• On September 18, 2012, Qsymia became available on the US market.

How should this medicine be used?

• Pregnancy testing is recommended before initiating Qsymia.
• Determine the patient's BMI.

Recommended dosage:

• Qsymia 3.75 mg/23 mg (phentermine 3.75 mg/topiramate 23 mg extended-release) daily for 14 days; then increase to 7.5 mg/46 mg daily.
• Discontinue or escalate dose (as described) if 3% weight loss is not achieved after 12 weeks on 7.5 mg/46 mg dose.
• Discontinue Qsymia if 5% weight loss is not achieved after 12 weeks on maximum daily dose of 15 mg/92 mg.
• Discontinue 15 mg/92 mg dose gradually (as described) to prevent possible seizure.
• Do not exceed 7.5 mg/46 mg dose for patients with moderate or severe renal impairment or patients with moderate hepatic impairment

Administration:

• Take once daily in morning. Avoid evening dose to prevent insomnia.

What are the dosage forms and brand names of this medicine?

This medicine is available in fallowing doasage form:

• As Capsules: (phentermine mg/topiramate mg extended-release)
• 3.75 mg/23 mg
• 7.5 mg/46 mg
• 11.25 mg/69 mg
• 15 mg/92 mg

This medicine is available in fallowing brand namesː

• Qsymia

What side effects can this medication cause?

The most common side effects of this medicine include:

• paraesthesia
• dizziness
• dysgeusia
• insomnia
• constipation
• dry mouth

Qsymia can cause serious side effects, including:

• Birth defects (cleft lip and cleft palate)
• Increases in heart rate
• Suicidal thoughts or actions
• Serious eye problems

What special precautions should I follow?

• Qsymia Can cause fetal harm. Pregnancy testing recommended before initiating Qsymia and monthly during therapy; advise use of effective contraception. Qsymia is available through a limited program under a Risk Evaluation and Mitigation Strategy (REMS).
• Qsymia can cause an increase in resting heart rate. Monitor heart rate in all patients, especially those with cardiac or cerebrovascular disease.
• Antiepileptic drugs (AEDs), including topiramate, a component of Qsymia, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Monitor for depression or suicidal thoughts. Discontinue Qsymia if symptoms develop.
• A syndrome consisting of acute myopia associated with secondary angle closure glaucoma has been reported in patients treated with topiramate, a component of Qsymia. Discontinue Qsymia.
• Mood and Sleep Disorders may occur. Consider dose reduction or withdrawal for clinically significant or persistent symptoms.
• Qsymia can cause cognitive dysfunction (e.g., impairment of concentration/attention, difficulty with memory, and speech or language problems, particularly word-finding difficulties). Caution patients about operating automobiles or hazardous machinery when starting treatment.
• Hyperchloremic, non-anion gap, metabolic acidosis (decreased serum bicarbonate below the normal reference range in the absence of chronic respiratory alkalosis) has been reported in patients treated with Qsymia. Measure electrolytes before/during treatment.
• Qsymia can cause an increase in serum creatinine that reflects a decrease in renal function. Measure creatinine before/during treatment.
• Weight loss may increase the risk of hypoglycemia in patients with type 2 diabetes mellitus treated with insulin and/or insulin secretagogues (e.g., sulfonylureas). Qsymia has not been studied in combination with insulin.

What to do in case of emergency/overdose?

Symptoms of overdosage may include:

• overdose of phentermine may be associated with restlessness, tremor, hyperreflexia, rapid respiration, confusion, aggressiveness, hallucinations, and panic states. Fatigue and [[]]depression usually follow the central stimulation. Cardiovascular effects include arrhythmia, hypertension or hypotension, and circulatory collapse. Gastrointestinal symptoms include nausea, vomiting, diarrhea, and abdominal cramps. Fatal poisoning usually terminates in convulsions and coma.
• Topiramate overdose has resulted in severe metabolic acidosis. Other signs and symptoms include convulsions, drowsiness, speech disturbance, blurred vision, diplopia, mentation impaired, lethargy, abnormal coordination, stupor, hypotension, abdominal pain, agitation, dizziness, and depression.

Treatment of overdosage:

• In the event of a significant overdose with Qsymia, if the ingestion is recent, the stomach should be emptied immediately by gastric lavage or by induction of emesis. Appropriate supportive treatment should be provided according to the patient's clinical signs and symptoms.
• Activated charcoal has been shown to adsorb topiramate in vitro.
• Hemodialysis is an effective means of removing topiramate from the body.
• Management of acute phentermine intoxication is largely symptomatic and includes lavage and sedation with a barbiturate.
• Acidification of the urine increases phentermine excretion.
• Intravenous phentolamine has been suggested for possible acute, severe hypertension, if this complicates phentermine overdosage.

Can this medicine be used in pregnancy?

• Qsymia is contraindicated in pregnant patients.

Can this medicine be used in children?

• Safety and effectiveness of Qsymia in pediatric patients below the age of 18 years have not been established and the use of Qsymia is not recommended in pediatric patients.

What are the active and inactive ingredients in this medicine?

• Active Ingredient: phentermine hydrochloride and topiramate extended-release
• Inactive Ingredients: methylcellulose, sucrose, starch, microcrystalline cellulose, ethylcellulose, povidone, gelatin, talc, titanium dioxide, FD&C Blue #1, FD&C Red #3, FD&C Yellow #5 and #6, and pharmaceutical black and white inks.

Who manufactures and distributes this medicine?

• Qsymia is a registered trademark of VIVUS, Inc.
• VIVUS, Inc
• 900 E. Hamilton Ave., Suite 550
• Campbell, CA

What should I know about storage and disposal of this medication?

• Store Qsymia at room temperature between 59°F to 77°F (15°C to 25°C).
• Risks of sudden stoppage of Phentermine/Topiramate

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• Dailymed label info on Phentermine/topiramate
• FDA Phentermine/topiramate

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