A Friend Of Mine Had Three Of His Teeth Pulled

A friend of mine had three of his teeth pulled out. His dentist gave him 3 medications one of which is the metronidaxole. After taking them he lost any sensation on his penis, can't have erection at all. In other words can't have sex no matter what he or his wife does. What do you think happen, what can he do and not do. He is only 45 years old and his wife ten years younger.is there anything he can take for temporary period till he becomes normal again. Appreciate all the help you can offer.