Pimozide

Mechanism :

Pimozide is a diphenylbutylpiperidine derivative with neuroleptic properties that has been found to be useful in the management of chronic schizophrenic patients. It is relatively non-sedating and can be administered in a single daily dosage.

Indication :

• Tourette syndrome

Contraindications :

Contraindicated in CNS depression, comatose states, liver disorders, renal insufficiency, and blood dyscrasias, and in individuals who have previously displayed hypersensitivity to the drug. It should not be used in depressive disorders or Parkinson’s syndrome. Pimozide is contraindicated in patients with congenital long QT syndrome, patients with a history of cardiac arrhythmias, or patients taking other drugs which prolong the QT interval of the ECG. A pre-treatment ECG is thus recommended to exclude these conditions.

Dosing :

Adverse Effect :

Tremor, rigidity, hypersalivation, bradykinesia, akathisia, acute dystonia, tardive dyskinesia, Neuroleptic Malignant Syndrome, insomnia, restlessness, agitation, drowsiness, decreased attention, fatigue, depression, irritability, tension, jitteriness, excitement, aggressiveness, anxiety, confusion, nightmares, hallucinations, dystonic reactions, dizziness or vertigo, weakness, excessive sweating, body temperature dysregulation, headache, EEG changes, increased incidence of epileptic seizures opisthotonos, hyperreflexia and grand mal convulsions.

Autonomic: Dry mouth, blurred vision, difficulty with accommodation, urinary retention, and urinary and faecal incontinence. Nasal congestion, paralytic ileus and reversed epinephrine effect.

Cardiovascular: Hypotension, tachycardia and fluctuations in blood pressure. QT-interval prolongation and/or ventricular arrhythmias have very rarely been reported.

Gastrointestinal: Anorexia, nausea and/or vomiting, constipation, diarrhoea, and abdominal cramps or pain.

Endocrine: Hyperprolactinemia, galactorrhea, gynecomastia, amenorrhea and impotence.

Miscellaneous: Urticaria, erythematous rash, fever, laryngeal edema, angioneurotic edema, asthma, anaphylactoid reactions, hyperpyrexia, obstructive jaundice, biliary stasis, photosensitivity, eczema, exfoliative dermatitis, maculopapular and acneiform reactions, and alopecia. Blood dyscrasias (agranulocytosis, leukopenia, granulocytopenia, pancytopenia, thrombocytopenic purpura, eosinophilia, anemia, aplastic anemia) have also occurred.

Cerebral edema, peripheral edema and altered cerebrospinal fluid proteins have been observed with other antipsychotic agents.

Interaction :

Macrolide Antibiotics, Tricyclic Anti-Depressants, other Antipsychotic Drugs: Concurrent use is not recommended as potentially an increased risk of arrhythmias. Drugs which may prolong the QT interval such as quinine, mefloquine, amiodarone, bretylium, disopyramide; procainamide, quinidine, sotalol, terfenadine, astemizole are contraindicated. Drugs causing electrolyte imbalance are also contraindicated(including diuretics, but if necessary, a potassium-sparing diuretic is preferred).

Renal Dose :

Hepatic Dose :