Astemizole
Astemizole (marketed under the brand name Hismanal, developmental code R43512) was a second-generation antihistamine drug that has a long duration of action. Astemizole was discovered by Janssen Pharmaceutica in 1977. It has been withdrawn from the market in most countries because of rare but potentially fatal side effects (QTc interval prolongation and related arrhythmias due to hERG channel blockade).
Cimetidine
Reported side effects of cimetidine include diarrhea, rashes, dizziness, fatigue, constipation, and muscle pain, all of which are usually mild and transient. It has been reported that mental confusion may occur in the elderly. Because of its hormonal effects, cimetidine rarely may cause sexual dysfunction including loss of libido and erectile dysfunction and gynecomastia (0.1–0.2%) in males during long-term treatment. Rarely, interstitial nephritis, urticaria, and angioedema have been reported with cimetidine treatment. Cimetidine is also commonly associated with transient raised aminotransferase activity; hepatotoxicity is rare.