BRAND NAMES: Adipex-P, Obenix, Oby-Trim
DRUG CLASS AND MECHANISM: Phentermine is in a class of drugs called anorectics which decrease appetite by possibly changing brain levels of serotonin. Phentermine is a nervous system stimulator like the amphetamines, causing stimulation, elevation of blood pressure, and faster heart rates.

Obesity is usually defined as being 20% over ideal weight with resultant increase in certain diseases including high cholesterol levels, heart disease, high blood pressure, gallbladder disease, type II diabetes mellitus, hardening of the arteries, and degenerative arthritis. Weight loss decreases blood pressure, cholesterol levels, and improves diabetes control.

PRESCRIPTION: yes

GENERIC AVAILABLE: yes

PREPARATIONS: Tablets: 30mg, 37.5mg.

STORAGE: Phentermine should be stored in a tight container at room temperature.

PRESCRIBED FOR: Phentermine is usually used as a short- term drug along with diet and behavior modification to treat obesity. Recently, it has been combined with diet and fenfluramine (Pondimin) and used over longer terms in selected obesity patients (P & P diets) with some favorable long-term modest weight loss.

DOSING: Phentermine should be taken after breakfast; evening doses should be avoided because of secondary insomnia.

DRUG INTERACTIONS: Phentermine should not be taken by patients with glaucoma, hyperthyroidism, or a history of drug abuse or psychotic illnesses. Phentermine is not recommended in patients with high blood pressure that is not well controlled. Patients on phentermine should have their blood pressure closely followed. Insulin requirements may change in patients on phentermine; alcohol can cause a drug interaction. Abrupt stoppage of the drug can cause withdrawal with fatigue and depression. Phentermine is potentially addicting. Phentermine is not recommended for patients with symptomatic heart disease including rhythm problems.

SIDE EFFECTS: Side effects include diarrhea, dry mouth, constipation, an unpleasant taste, hives, impotence, palpitations, high blood pressure, and fast heart rates. Central nervous system side effects include overstimulation, insomnia, restlessness, tremor, and dizziness