Viagra doses range from 25 milligrams, 50 milligrams and 100 milligrams.
Your doctor will adjust the dosage if the drug is not working properly for you.
It should not be taken more than once a day.
If you are older than age 65, or have serious liver or kidney problems, your doctor may start you at the lowest dose (25 mg) of VIAGRA.
If you are taking protease inhibitors, such as for the treatment of HIV, your doctor may recommend a 25 mg dose and may limit you to a maximum single dose of 25 mg of VIAGRA in a 48 hour period
If you are taking alpha-blocker therapy, you should not take more than 25 mg of Viagra at the same time (within 4 hours) as your dose of alpha-blocker.
Overdose
In case of an accidental overdose, seek medical attention immediately.