Phentermine
Indications
Phentermine is used for:
Obesity
Adult Dose
Oral
Anorectic in short-term treatment of moderate to severe obesity
Adult: As phentermine HCl: 15-37.5 mg once daily in the morning; higher dose of 37.5 mg may be given in 2 divided doses. Individualise to achieve adequate response w/ lowest effective dose. As modified-release ion-exchange resin complex: 15-30 mg once daily in the morning.
Child Dose
Renal Dose
Administration
Contra Indications
Hyperthyroidism, history of CV disease (e.g. coronary artery disease, arrhythmias, CHF, uncontrolled HTN), glaucoma, history of alcohol/drug abuse, agitated states. Pregnancy and lactation. Concomitant or w/in 14 days of MAOI use.
Precautions
Patient w/ HTN, DM, seizure disorder, Tourette's syndrome. Avoid abrupt withdrawal. Renal impairment. Patient Counselling May impair ability to drive or operate machinery. Monitoring Parameters Monitor wt, waist circumference and BP.
Pregnancy-Lactation
Pregnancy category: X
Lactation: Unknown if excreted in milk; contraindicated
Interactions
Primary pulmonary HTN or valvular heart disease may occur when phentermine is used concurrently w/ fenfluramine or dexfenfluramine. May decrease hypotensive effect of adrenergic neuron blocking drugs (e.g. guanethidine, clonidine, methyldopa). CNS stimulant effect may be increased by thyroid hormones.
Potentially Fatal: Increased risk of hypertensive crisis w/ MAOI.
Adverse Effects
Side effects of Phentermine :
Frequency Not Defined
Bad taste in mouth
Blurred vision
Changes in libido
Chills
Constipation
Diarrhea
Drug-induced GI disturbance
Dry mouth
Dysphoric mood
Dysuria
Excitement
Hair loss
Headache
Hypertension
Impotence
Insomnia
Myalgia
Nausea
Nervousness
Palpitations
Restlessness
Tachycardia
Tremor
Urticaria
Vomiting
Serious
Heart valve disorder
Primary pulmonary hypertension
Psychotic disorder
Mechanism of Action
Phentermine is a sympathomimetic amine that exerts its appetite suppressant effect through a mechanism which appears to be secondary to CNS effects, including stimulation of the hypothalamus to release norepinephrine.