Hello - thanks for asking your question.
100mg of Viagra is the highest recommended dose. If it isn't working, you may want to explore other causes of erectile dysfunction.
I would suggest some tests to make sure that there is not an anatomical or disease-related condition that is causing the dysfunction.
A testosterone level can be performed since a low level can affect sexual potency. An ultrasound can evaluate the blood vessels supplying the penis.
Nocturnal penile tumescence testing determines the quantity and quality of the erection. It can identify men with either arterial or venous dysfunction who may benefit from surgery.
If not already done, I would suggest a urology referral.
Followup with your personal physician is essential.
This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.
Thanks,
Kevin, M.D.