Master Low Potency Antipsychotics

Chlorpromazine is a low potency antipsychotic used for psychosis, schizophrenia, and manic episodes. This drug has the side effect of hypotension and also has anti-histamine properties, which counteract the extrapyramidal symptoms experienced with antipsychotics.

Chlorpromazine accumulates in the corneal stroma of the eye. After light exposure, cellular damage occurs, as the drug is a phototoxic compound. This effect may lead to color blindness and benign pigmentation of the cornea.

Thioridazine is an antipsychotic medication typically used to treat schizophrenia and psychosis. It is a low potency antipsychotic and has very serious adverse effects. This drug can lead to extrapyramidal symptoms, neuroleptic malignant syndrome, impotence, and autonomic side effects.

Thioridazine can lead to retinal deposits in patients.

The α1 antagonist effects of both these low potency antipsychotic medications may lead to hypotension and, rarely, impotence or anorgasmia.

Anticholinergic effects, such as dry mouth, urination difficulty, obstipation, induction of glaucoma, postural hypotension, and sinus tachycardia, may occur. However, these are seen less often than with most other mildly potent antipsychotics.

Low potency antipsychotic drugs such as chlorpromazine and thioridazine possess strong antihistamine properties due to their ability to antagonize histamine H1 receptors. By blocking these receptors, they inhibit the action of histamine, a neurotransmitter involved in various physiological processes, including allergic responses and wakefulness. This blockade results in sedative effects and a reduction in allergic symptoms such as itching, sneezing, and nasal congestion. Additionally, the antihistamine activity of these drugs contributes to their overall therapeutic profile in managing psychotic symptoms and conditions like schizophrenia. However, they are often associated with more pronounced sedation and anticholinergic side effects compared to higher-potency antipsychotics.