Thanks for posting your concern in HCM. Both diabetes and hypertension can cause erectile dysfunction. Among the medications you mentioned, researchers suggest that metformin actually improve in erectile dysfunction. Further researches are needed to conclude whether it can be used for the treatment of erectile dysfunction. Amlodipine and other calcium channel blockers, can cause erectile dysfunction very rarely so does antihypertensive medications of some other groups. But, hypertension itself is more common a culprit in that case. Rather, I feel both the medications are widely used by doctors and metformin is even considered the first line drug for diabetes. Hence, I think the present disease conditions are more of concern and you need to strictly control them for an uneventful life. For, the betterment of eretile dysfunction, you should also reduce stress which is a more common cause of this. If the problem persists you need to do blood examination for hormonal assessment (Testosterone, SHBG, TSH, Prolactin, ) and furthermore USG of penis and testes. You should also check serum PSA level. For further evaluation, please consult an endocrinologist or write back to us with the reports.