Medications such as blood pressure medications (especially beta-blockers), heart medications (such as
digoxin), some peptic ulcer medications, sleeping pills,
and antidepressants may also cause erectile dysfunction.
http://www.pennhealth.com/ency/article/003164.htm
Talk to your partner openly about any fears or apprehensions,eat nutritious healthy food,exercise regularly and cut down on smoking or alcohol if you are taking it.