Are there any antihistamines that can be taken safely for men with enlarged prostate?

Yes: Some antihistamines have been implicated in cases of urinary retention in men. A large prostate is per se a risk, and certain medications can precipitate this problem. However, the most potent risk is from decongestants like sudafed and phenylephrine which constrict the bladder neck and are often combined with antihistamine. Nonsedating medications like Claritin (loratadine) should carry less risk by itself.

Antihist and prostat: Newer antihistamines such as loratadine, fexofenadine, and Cetirizine have less affect on smooth muscles and usually are tolerated. Start with lower doses to access tolerance.