Premature ejaculation.

Patient: My husband is not a nervous person or depressed however he never manages a longer erection than a half minute before finishes this gets me really upset as his wife because its so short and makes the excitement and waiting short lived. this has always been the problem and im wondering what can he take to help this problem?we have tried holding the head of the penis before and it just irritates me to have to remember and usually doesnt work even.please help mea unhappy wife