Notes on using Viagra

Viagra may be ineffective or even dangerous to consume in some medical conditions. It is recommended that you consult with your healthcare assistance on the possible use of Viagra if you have one of the following conditions:

- consuming prescription or nonprescription medicine, herbal preparation, or dietary supplement
- have an allergy to any substances: food, medicine, etc.
- have any factors that may cause priapism (like deformed penis)
- have vision issues
- kidney or liver diseases, blood pressure issues, ulcers, bleeding problems, heart or blood vessel issues
- have had a heart attack, stroke, or life-threatening irregular heartbeat in the last half of year

Certain groups of drugs can also reduce the effectiveness of Viagra or even produce negative or life-threatening side effects. So be careful and consult with your doctor if you are prescribed one of the following types of drugs:

- Alpha-blockers , amlodipine, high blood pressure medicines, nitrates, or nitroprusside
- Azole antifungals, cimetidine, H2 agonists, HIV protease inhibitors, macrolide antibiotics, or telithromycin
 Bosentan or rifampin