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 It has been withdrawn from the market in most countries because of rare but potentially fatal side effects (QTc interval prolongation and related arrhythmias due to hERG channel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).
Dihydrotestosterone
5α-Reductase inhibitors are overall well-tolerated and show a low incidence of adverse effects. Sexual dysfunction, including erectile dysfunction, loss of libido, and reduced ejaculate volume, may occur in 3.4 to 15.8% of men treated with finasteride or dutasteride. A small increase in the risk of affective symptoms including depression, anxiety, and self-harm may be seen. Both the sexual dysfunction and affective symptoms may be due partially or fully to prevention of the synthesis of neurosteroids like allopregnanolone rather necessarily than due to inhibition of DHT production. A very small risk of gynecomastia has been associated with 5α-reductase inhibitors (1.2 to 3.5%). Based on reports of 5α-reductase type II deficiency in males and the effectiveness of 5α-reductase inhibitors for hirsutism in women, reduced body and/or facial hair growth is a likely potential side effect of these drugs in men. There are very few studies evaluating the side effects of 5α-reductase inhibitors in women. However, due to the known role of DHT in male sexual differentiation, 5α-reductase inhibitors may cause birth defects such as ambiguous genitalia in the male fetuses of pregnant women. As such, they are not used in women during pregnancy.