Indications
Opsonil is used to treat schizophrenia and other forms of psychosis (particularly the paranoid type), as well as mania and hypomania. It can also help manage anxiety, agitation, excitement, and violent or dangerously impulsive behaviour, usually as an add-on treatment for a short period. Other uses include relieving persistent hiccups and easing nausea and vomiting in terminal illness when other medicines haven't worked or aren't available. It is also used for childhood schizophrenia and autism.
⚠️ Always consult a registered physician before taking any medicine.
Pharmacology
Chlorpromazine works by blocking several different receptors on the nerve cells that receive messages in the brain and body. Its effects depend on which receptor it blocks.
On dopamine receptors (subtypes D1, D2, D3 and D4), it acts as an antipsychotic. This helps with both the productive symptoms (such as hallucinations and delusions) and the unproductive symptoms (such as withdrawal and flat emotions) of psychosis.
On serotonin receptors (5-HT1 and 5-HT2), it can ease anxiety, lift mood and reduce aggression. It also softens some extrapyramidal side effects. But the same blocking can cause weight gain, a fall in blood pressure, sedation and difficulty with ejaculation.
On histamine receptors (H1), it causes sedation and helps prevent vomiting. It can also bring on vertigo, a fall in blood pressure and weight gain.
On alpha1 and alpha2 receptors, it blocks the effects of adrenaline-like hormones. This lowers blood pressure, and the body may respond with a faster heartbeat (reflex tachycardia). Other effects include vertigo, sedation, excess saliva, incontinence and sexual problems. It may also reduce pseudoparkinsonism, although experts are not agreed on this.
On muscarinic (cholinergic) M1 and M2 receptors, it causes anticholinergic effects such as dry mouth, blurred vision, constipation, difficulty or inability to pass urine, a fast heartbeat (sinus tachycardia), ECG changes and memory loss. Blocking these receptors may, however, reduce some extrapyramidal side effects.
Chlorpromazine also weakly stops dopamine from being taken back into the nerve cell (reuptake), which may cause mild antidepressant and antiparkinsonian effects. The same action could in principle lead to psychomotor agitation and a worsening of psychosis, though this is very rarely seen in clinical use.
Pregnancy & Breastfeeding
Pregnancy category C. Animal studies using the oral route have shown reproductive toxicity, with dose related effects on the embryo and foetus, including increased resorptions and foetal deaths. A higher rate of malformations was seen in mice, but only at doses that were also toxic to the mother. Animal data on reproductive toxicity with the parenteral route are insufficient. In humans, the teratogenic risk of chlorpromazine has not been formally assessed. Various prospective epidemiological studies of other phenothiazines have produced conflicting findings on teratogenic risk. Chlorpromazine passes into breast milk in varying amounts, so it is not recommended for breastfeeding mothers unless the expected benefit is judged to outweigh any possible risk.
⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.
Dosage Reference
⚠️ Reference ranges from official sources only. Consult your doctor for personalized dosing.
Side Effects & Interactions
Side Effects
No side-effect data recorded yet.