lessness, dizziness, insomnia, euphoria, dysphoria, tremor, headache, psychosis.
Gastrointestinal
Dryness of the mouth, unpleasant taste, diarrhea, constipation, other gastrointestinal disturbances.
Allergic
Urticaria.
Endocrine
Impotence, changes in libido.
DRUG ABUSE AND DEPENDENCE
Controlled Substance
Phentermine is a Schedule IV controlled substance.
Abuse
Phentermine is related chemically and pharmacologically to the amphetamines. Amphetamines and other stimulant drugs have been extensively abused and the possibility of abuse of phentermine should be kept in mind when eva luating the desirability of including a drug as part of a weight reduction program.
Dependence
Abuse of amphetamines and related drugs may be associated with intense psychological dependence and severe social dysfunction. There are reports of patients who have increased the dosage of these drugs to many times than recommended. Abrupt cessation following prolonged high dosage administration results in extreme fatigue and mental depression; changes are also noted on the sleep EEG. 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.
OVERDOSAGE
The least amount feasible should be prescribed or dispensed at one time in order to minimize the possibility of overdosage.
Acute Overdosage
Manifestations of acute overdosage include restlessness, tremor, hyperreflexia, rapid respiration, confusion, assaultiveness, 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. Overdosage of pharmacologically similar compounds has resulted in fatal poisoning usually terminates in convulsions and coma.
Management of acute phentermine hydrochloride intoxication is largely symptomatic and includes lavage and sedation with a barbiturate. Experience with hemodialysis or peritoneal dialysis is inadequate to permit recommendations in this regard. Acidification of the urine increases phentermine excretion. Intravenous phentolamine (Regitine®, CIBA) has been suggested on pharmacologic grounds for possible acute, severe hypertension, if this complicates overdosage.
Chronic Intoxication
Manifestations of chronic intoxication with anorectic drugs include severe dermatoses, marked insomnia, irritability, hyperactivity and personality changes. The most severe manifestation of chronic intoxications is psychosis, often clinically indistinguishable from schizophrenia. See DRUG ABUSE AND DEPENDENCE.
DOSAGE AND ADMINISTRATION
Dosage should be individualized to obtain an adequate response with the lowest effective dose.
The usual adult dose is one tablet three times a day ½ hour before meals. This tablet is scored to facilitate administering one half of the usual dosage for patients not requiring the full dose. Phentermine hydrochloride is not recommended for use in pediatric patients less than or equal to 16 years of age.
Late evening medication should be avoided because of the possibility of resulting insomnia.
HOW SUPPLIED/STORAGE AND HAND |
