It is not for use in pregnancy, breastfeeding or children under twelve years. Do not take phentermine if suffering from uncontrolled high blood pressure, heart disease, overactive thyroid gland, recent stroke, glaucoma, hyperactive state, mania, schizophrenia, depression, anorexia nervosa or a history of drug abuse. Use with caution in high blood pressure, angina, diabetes and epilepsy.
Patients should never exceed the recommended dosage. It is not for long-term use and the blood pressure should be checked regularly. Always use it in conjunction with an appropriate diet and exercise program.
Side effects may include palpitations, rapid heart rate, over stimulation, restlessness, sleeplessness, tremor, rash may occur.
Phentermine may interact with MAOI, sympathomimetics, sedatives, insulin, hypoglycaemics (treat diabetes), clomipramine, thyroxine, SSRI (treat depression), caffeine and alcohol.
An overdose is serious as it may cause restlessness, tremor, confusion, hallucinations, panic state, fatigue, irregular heart beat, high blood pressure, vomiting, diarrhoea, heart attack, convulsions, coma and death.
Phentermine is less commonly used these days due to the significant risk of dependence and addiction.