Antipsychotic Medications Anti-psychotic Drugs chlorpromazine, Thorazine

Antipsychotic: chlorpromazine, Thorazine

Generic Name: chlorpromazine
Brand Name(s): Thorazine
Common Use: Antipsychotic

Antipsychotic - Antiemetic

Chlorpromazine is an aliphatic phenothiazine. The aliphatic phenothiazines are highly sedating which is often apparent at the start of therapy; with time some tolerance to this effect develops. Chlorpromazine has strong alpha-adrenergic blocking activity and can cause orthostatic hypotension. Infrequently prolongation of the QT interval may occur. Chlorpromazine has moderate anticholinergic activity manifested as occasional dry mouth, blurred vision, urinary retention and constipation.

The management of psychotic disorders including manifestations of manic depressive illness, manic phase and severe behavioral problems in children; nausea and vomiting due to stimulation of the chemoreceptor trigger zone.

Contraindications
Comatose or depressed states due to CNS depressants; blood dyscrasias; bone marrow depression; liver damage. Hypersensitivity to chlorpromazine. Cross allergenicity with other phenothiazines may occur.

Should be avoided in children or adolescents with signs or symptoms suggestive of Reye's Syndrome. Its antiemetic effect may mask the signs and its CNS effect may be confused with the signs of Reye's Syndrome or other encephalopathies.

Adverse Side Effects

In general members of the aliphatic group of phenothiazines have strong sedative, hypotensive and anticholinergic properties and mild to moderate extrapyramidal effects.
Anticholinergic effects including dry mouth, blurred vision, constipation, ileus, nasal stuffiness, photophobia. Syncope and impaired temperature regulation have also occurred. Chlorpromazine has peripheral alpha-adrenergic blocking activity. Its effects on the heart include: direct negative inotropic and quinidine-like actions. Its effects on the ECG include prolongation of the PR and QT intervals, blunting of the T wave and depression of the S-T segment. Ventricular arrythmia and sudden death have occurred rarely.
Orthostatic hypotension is common after parenteral administration and usually lasts one-half to 2 hours. Patients should be supine when parenteral chlorpromazine is administered. Tachycardia, fainting and dizziness have also occurred. Hypotension can also occur after oral administration. Tolerance to hypotensive effects generally develop over time, however hypotension can persist in some patients, especially the elderly.
Extrapyramidal reactions, including pseudoparkinsonism (with motor retardation, rigidity, mask like facies, pill rolling and other tremors, drooling, shuffling gait, etc.); dystonic reactions (including periroral spasms, trismus, tics, torticollis, oculogyric crises, protrusion of the tongue, difficulty swallowing, carpopedal spasm, opisthotonos of the back muscles); and akathisia. In addition, slowing of the EEG rhythm, disturbed body temperature and lowering of the convulsive threshold have occurred. Dizziness has been reported.
Itching, rash, hypertrophic papillae of the tongue, angioneurotic edema, erythema, allergic purpura, exfoliative dermatitis, photosensitivity. Contact dermatitis has occurred in personnel handling solutions or injections of chlorpromazine.
Increased prolactin secretion; gynecomastia, galactorrhea, mastalgia, altered libido, menstrual irregularities, weight gain, alterations in glucose tolerance and false positive pregnancy tests have occurred.
Nausea, vomiting, increase or decrease in appetite, gastric irritation, constipation, paralytic ileus, rarely diarrhea. Dry mouth.
Urinary retention, priapism, inhibition of ejaculation.
Agranulocytosis, leukopenia, granulocytopenia, eosinophilia, thrombocytopenia, anemia, aplastic anemia, pancytopenia. Agranulocytosis occurs in fewer than 1 in 10000 patients receiving chlorpromazine.
Cholestatic jaundice can occur infrequently (0.1-4%) and is usually part of a hypersensitivity reaction. Jaundice usually occurs within 2 to 4 weeks of initiation of therapy and chlorpromazine should be discontinued immediately. Rarely progression to chronic jaundice has occurred. Pre-existing liver dysfunction has not yet been proven to be a risk factor for this reaction. Signs and symptoms of cholestatic jaundice include; upper abdominal pain, nausea, flu-like symptoms, yellow skin and conjunctiva, fever, elevated liver enzymes, biliuria.
Cholestatic jaundice (see under Hepatic), various dermatoses (see under Dermatologic), blood dyscrasias (see under Hematologic), photosensitivity, laryngeal edema, bronchospasm, angioneurotic edema and anaphylactoid reaction.
A peculiar skin-eye syndrome has been recognized as an adverse effect following long-term treatment with phenothiazines. This reaction is marked by progressive pigmentation of areas of skin or conjunctiva and/or discoloration of the exposed sclera and cornea. Opacities of the anterior lens and cornea described as irregular or stellate in shape have also been reported. Patients receiving higher doses of phenothiazines for prolonged periods should have periodic complete eye examinations.

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