Psychomotor Stimulants

Psychomotor Stimulants

a. Amphetamine

Synthesis

Mode of action: Amphetamine increases synaptic dopamine and noradrenaline primarily by stimulating presynaptic release rather than by blockade of the reuptake as in the case of cocaine.

Uses: It is an anorectic and has been used in the weight control of obese individuals. It has potential for abuse and cardiovascular effects.

Dose: For narcolepsy, 10 mg/day, for obesity, 5–10 mg/day, 30–60 min before meals.

b. Fenfluramine (Pondialon)

Properties and uses: It is a white amophous powder, sparingly soluble in water, used as respiratory stimulant.

Assay: Dissolve the sample in chloroform and acetone. Add mercuric acetate solution and titrate with 0.1 N perchloric acid.

Synthesis

Dose: By oral route for adults: 20 mg thrice a day, 30 min to 1 h before each meal.

c. Phentermine

Synthesis

Use: It is used as an appetite suppressant.

Dose: The usual dose is 15–30 mg at breakfast.

d. Methylphenidate HCl (Ritalin)

Synthesis

Mode of action: It is similar to amphetamine, but superior in its pharmacological action. It increases the release of dopamine and noradrenaline, and it is useful in hyperkinetic children.

Properties and uses: It is a white fine crystalline powder, soluble in water, and sparingly soluble in chloroform and acetone. It is used as a potent CNS stimulant.

Dose: The usual dose by oral or parenteral is 10–60 mg/day.

e. Pemoline

Synthesis

Properties and uses: It is a white crystalline powder, slightly soluble in alcohol. It is used in the treatment of narcolepsy fatigue, mental depression, chronic schizophrenia, and as a mild stimulant in geriatric patients.