What potential ocular side effect is associated with Cetirizine?

Cetirizine is an antihistamine primarily used for the treatment of allergies, and it can produce various side effects, including some that affect the eyes. The ocular side effect associated with cetirizine is an oculogyric crisis, which involves involuntary upward eye movement and is a reaction that can occur with certain medications, including antihistamines.

Oculogyric crisis can manifest as eye spasms or abnormal movements, leading to discomfort and an unusual appearance. This reaction may be related to the drug's anticholinergic properties, which can affect the central nervous system and result in dystonic reactions.

In contrast, the other potential side effects listed, such as uveitis, acute glaucoma, or conjunctivitis, are not commonly associated with cetirizine use. Uveitis and acute glaucoma involve inflammation and increased intraocular pressure, respectively, while conjunctivitis is more often related to infections or allergies rather than the use of cetirizine.

Understanding these mechanisms helps clarify how cetirizine can lead to an oculogyric crisis as a side effect, distinguishing it from other, unrelated ocular conditions.