Review Question - QID 101705

Chlorpromazine, a typical antipsychotic, can cause corneal deposits that lead to cellular damage after light exposure and significant risk of blindness.

Typical antipsychotics such as chlorpromazine and thioridazine are primarily used for their antidopaminergic properties. However, the drugs also have anticholinergic, antihistaminic, and weak antiadrenergic effects, resulting in a broad side effect profile. Some of the significant side effects include constipation, sedation, hypotension, akathisia, and tardive dyskinesia. Since the advent of atypical antipsychotics, their use has decreased dramatically. Thioridazine also has ocular side effects, causing a pigmentery retinopathy that can easily be mistaken for retinitis pigmentosa.

Muench et al. review adverse effects of antipsychotics. They state, "as a class, the older first-generation antipsychotics are more likely to be associated with movement disorders, but this is primarily true of medications that bind tightly to dopaminergic neuroreceptors, such as haloperidol, and less true of medications that bind weakly, such as chlorpromazine."

Lehman et al. provide practice guidelines for treatment of schizophrenia and recommend "periodic ophthalmic examinations to consider possibility of pigmentary retinopathy and lenticular and corneal deposits in patients receiving prolonged therapy [with chlorpromazine]."

Illustration A shows an example of chlorpromazine-induced corneal deposits.
Illustration B shows an example of retinitis pigmentosa. The appearance is similar to that seen in the pigment deposition caused by prolonged thioridazine use.

Incorrect Answers:
Answer 1: Thioridazine, not chlorpromazine, can cause retinal deposits that resemble retinitis pigmentosa.
Answer 2: The cause of macular degeneration is unknown but thought to involve cumulative effects of lifetime oxidative stress. There are no identified medications that cause macular degeneration.
Answer 3: While the primary cause of glaucoma is thought to be multifactorial, an increased risk has been associated with the use of steroids and the antiepileptic drug topiramate.
Answer 4: Retinal hemorrhage is a finding seen in shaken baby syndrome. It is not associated with any medication use.