Procyclidine is indicated as an adjunct in the treatment of all types of parkinsonian syndromes. It is primarily used for symptomatic management of idiopathic (paralysis agitans), post-encephalitic, and arteriosclerotic Parkinsonism. It is also effective in controlling extrapyramidal symptoms such as pseudoparkinsonism, acute dystonic reactions, and akathisia induced by neuroleptic drugs, including phenothiazine derivatives.

Procyclidine hydrochloride is a low-toxicity antimuscarinic agent used in Parkinson’s disease. It is a synthetic tertiary amine. Its antiparkinsonian effect is achieved by reducing relative cholinergic overactivity believed to occur due to dopamine deficiency in Parkinsonism. It is well absorbed from the gastrointestinal tract and is rapidly cleared from body tissues. After intravenous administration, its action begins within 5–20 minutes and lasts for up to 4 hours.

Tablet: This is administered orally, preferably after meals.

• Parkinsonism: Initially 2.5 mg 3 times a day, then 5 mg 3 times a day and occasionally 5 mg at bedtime. The dosage being adjusted as tolerated or until the total daily dose reaches 20 to 30 mg divided into 3 to 4 doses.
• Drug induced extrapyramidal symptom: Initially 2.5 mg 3 times a day. The dosage being increased by 2.5 mg increment per day as needed and tolerated.

IM or IV injection: 5–10 mg, repeated if necessary after 20 minutes; maximum 20 mg daily can be given.

The anticholinergic effects of procyclidine may be enhanced when used with other anticholinergic agents such as amantadine. Concomitant use may also reduce the absorption of ketoconazole.

Procyclidine should be used with caution in children and elderly patients. Care is advised in patients with diarrhoea, cardiovascular disease, glaucoma, urinary retention, or hepatic and renal impairment. Its safety during pregnancy has not been established. Data regarding excretion in breast milk are not available

At usual doses, dry mouth is the most common adverse effect. Occasionally, blurred vision, pupil dilation (mydriasis), and gastrointestinal disturbances such as nausea, vomiting, epigastric discomfort, and constipation may occur. Allergic reactions (e.g., skin rash) and muscle weakness are also possible. High doses may lead to dizziness, confusion, and hallucinations. Most side effects can be reduced by adjusting the dose or taking the medicine after meals.

The use of this drug during pregnancy, lactation, or in women of childbearing potential should be considered only after carefully weighing the potential benefits against possible risks to both mother and child.

Use in children is not well established; therefore, administration should be based on careful assessment of potential benefits versus risks.

Antiparkinson drugs

Store below 25°C, protected from light and moisture. Keep out of the reach of children.