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.

Acute 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. Manifestations of chronic intoxication with anorectic drugs include severe dermatoses, marked insomnia, irritability, hyperactivity and personality changes. A severe manifestation of chronic intoxication is psychosis, often clinically indistinguishable from schizophrenia.

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 (Regitine®, CIBA) has been suggested for possible acute, severe hypertension, if this complicates phentermine overdosage.

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. The clinical consequences were not severe in most cases, but deaths have been reported after poly-drug overdoses involving gram amounts of topiramate. A patient who ingested a dose between 96 and 110 g topiramate was admitted to hospital with coma lasting 20 to 24 hours followed by full recovery after 3 to 4 days.

Activated charcoal has been shown to adsorb topiramate in vitro. Hemodialysis is an effective means of removing topiramate from the body.

Qsymia is contraindicated in the following conditions:

• Pregnancy [see WARNINGS AND PRECAUTIONS and Use in Specific Populations]
• Glaucoma [see WARNINGS AND PRECAUTIONS]
• Hyperthyroidism
• During or within 14 days following the administration of monoamine oxidase inhibitors [see DRUG INTERACTIONS]
• Known hypersensitivity or idiosyncrasy to the sympathomimetic amines [see ADVERSE REACTIONS].

Last reviewed on RxList: 4/8/2013
This monograph has been modified to include the generic and brand name in many instances.