by Dr. Manura Nanayakkara

Created on: June 11, 2010

This is the common brand name of prescription only generic drug Chlorpromazine. It is the prototypal antipsychotic drug used in schizophrenia, which revolutionalized psychopharmacology in 1950s. It is in the drug group Phenothiazine. Main side effects are sedation, dry mouth and abnormal movements.

 Largactil is used mainly as an anti psychotic medication for patients with schizophrenia. It is also used for nausea and vomiting, as an anti histamine, symptomatic treatment of Hiccups, and to control anxiety/tension.

 This drug blocks Dopamine, Histamine, and Acetyl Choline receptors. This is responsible for its therapeutic effect as well as side effects.

 Patient’s complete medical history including allergies and over the counter medications currently taking is important to the prescribing doctor. Doctor should know whether the patient is having kidney diseases, liver problems, cardiac diseases, Parkinson’s disease, epilepsy, Myasthenia Gravis, Enlargement of the prostate gland or susceptibility to angle closure glaucoma. Doctor should also know whether the patient is pregnant, planning to get pregnant or breast feeding.

 How to minimize side effects

 Largactil should be taken as a whole with full glass of water. It should not be crushed before use and it should be used as prescribed by the doctor. Doctor will give several medications (Benzhexol) to minimize side effects like abnormal movements.  Doctor will prescribe Largactil, usually at night to minimize daytime sleepiness.

 Common side effects

 Drowsiness is the most common side effect patients complain, especially at start of the treatment. This can affect skilled tasks such as operating machinery and driving. Drowsiness is enhanced by taking alcohol.

 Abnormal involuntary movements may occur in all age groups and at any dose. But they occur more frequently in children and young adults, following intravenous administration, and with higher doses. Abnormal movements include movements in neck, limbs, and rhythmic protrusion of the tongue. They occur usually after 24 – 48 hours after starting therapy and decrease over 24 h following discontinuation of the drug. Most patients respond rapidly to treatment with diazepam and anti cholinergic medication like Benzhexol.

 Other common side effects are dry mouth, constipation, confusion in elderly, difficulty in urination, and blurred vision.

 Uncommon side effects

 Headache, seizures, gastro intestinal disturbances, cardiac rhythm abnormalities, and reduced blood pressure are other uncommon side effects.

 Patient can faint after taking this drug due to reduced blood pressure, especially early in the regimen. This medication sometimes causes hormonal disturbances, which can leads to menstrual disturbances, abnormal milk secretion from breasts, impotence, sexual dysfunction and weight gain.

 Neuroleptic Malignant Syndrome is a potentially life threatening complication of Largactil. If the patient rapidly becomes unconscious with fever, muscle rigidity, low/high blood pressure, sweating, and urinary incontinence then he/she must be sent to an emergency medical unit.

 Sources

 British National Formulary

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