Didrex is a brand name for Benzphetamine. Benzphetamine hydrochloride is a sympathomimetic amine which acts as anorectic agent and is used for the treatment of obese and overweight patients. This is similar to amphetamine. Actions include central nervous system stimulation and elevation of blood pressure. Tachyphylaxis and tolerance have been demonstrated with all drugs of this class in which these phenomena have been looked for. Each DIDREX Tablet, for oral administration, contains 50 mg of benzphetamine hydrochloride and Calcium Stearate, Corn Starch, Erythrosine Sodium. FD & C Yellow No. 6, Lactose, Povidone, Sorbitol.

Mode of action of Didrex:

Didrex mainly acts on the central nervous system by inhibiting the appetite. It effects directly on the appetite centre and suppresses it, along with other metabolic effects. It also elevates the blood pressure which also may result in feeling nauseating and anorexic, hence reducing the hunger and so does the diet.

Didrex Prescription:

Like all other obesity treatment drugs, this also has some potential for addiction. Therefore it should be used only with consultancy with doctor or on doctors' instructions. Didrex comes in the form of tablets; 50 mg (peach, round, imprinted with DIDREX 50, scored). It comes in 100 and 500 tablets packing in bottles. It should be stored at room temperature and in cool dry place, away from the reach of children.

Precautions:

Patients with Diabetes would need to have their dose adjusted along with the use of Didrex.
Patients with hypertension, as Didrex increase the blood pressure.
Patients with history of anorexia or any drug abuse.
Patients with irregular heartbeats; arrhythmias.
Lactating mothers.
Patient under 18 years of age.

Contraindications:

Patients with advanced arteriosclerosis.
Patients with symptomatic cardiovascular disease.
Patients with moderate to severe hypertension.
Patients with hyperthyroidism.
Patients with known hypersensitivity or idiosyncrasy to sympathomimetic amines.
Patients with glaucoma.
Patients with agitated state or who have a history of drug abuse.
Patients with epilepsy or other seizure disorders.
Hypertensive crises have resulted when sympathomimetic amines have been used concomitantly or within 14 days following use of monoamine oxidase inhibitors. Didrex should not be used concomitantly with other CNS stimulants.
Didrex may cause fetal harm when administered to a pregnant woman. Amphetamines have been shown to be teratogenic and embryotoxic in mammals at high multiples of the human dose. Didrex is contraindicated in women who are or may become pregnant. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus.

Side Effects:

The usually faced mild side effects are:

Palpitation.
Tachycardia.
Elevation of blood pressure.
Overstimulation of CNS.
Restlessness.
Dizziness.
Insomnia.
Tremor.
Sweating.
Headache.
Psychotic episodes at recommended doses.
Depression following withdrawal of the drug.
Dryness of the mouth.
Unpleasant taste.
Nausea.
Diarrhea.
Gastrointestinal disturbances.
Urticaria and other allergic reactions involving the skin.
Changes in libido.

Apart from the mild side effects there are some very serious side effects that are been reported including:

There have been isolated reports of cardiomyopathy associated with chronic amphetamine use.
Teratogenic and embroyonic birth defects, if the mother has used Didrex in pregnancy.
Hypersenstivity reactions that may cause breathing disturbances, seizures, swelling over whole body and in extreme case hypersensitivity shock condition.
Over dosage may cause restlessness, tremor, tachypnea, confusion, assaultiveness and panic states.

Drug Interactions:

Blood pressure medicines.
Insulin may not cause very serious side effects but the dose should be adjusted.
MAO inhibitors (e.g., furazolidone, linezolid, moclobemide, phenelzine, selegiline, tranylcypromine).
Tricyclic antidepressants (e.g., doxepin, imipramine).
Drugs that affect the pH of urine (e.g., sodium bicarbonate).
Other drugs used to reduce weight. Alcohol may increase the dizziness effects of this medicine.
Alcohol use.
"Stimulant" drugs that may increase your heart rate such as decongestants or caffeine. Decongestants are commonly found in cough-and-cold medicines. If you are uncertain your medicines contain either of these ingredients, consult your pharmacist. Do not start or stop any medicine without doctor or pharmacist approval.