People's Pharmacy

Viagra

Generic Name:sildenafil

Revised:4/1/2000

Table of Contents

Side Effects and Interactions

Side effects associated with Viagra include headache, flushing or upset stomach.

Vision may also be affected, which may make it difficult to discriminate between blue and green.

Nasal congestion, diarrhea, dizziness, urinary tract infection and rash have also been reported.
Report any symptoms to your physician promptly.

Erections that last longer than four hours are rare but require emergency medical attention to avoid permanent damage to the penis.

Nitroglycerin (under brand names such as Minitran, Nitro-Bid, Nitro-Dur, Nitrogard, Nitrolingual, Nitrong, Nitrostat, Transderm-Nitro) and nitrate-based heart and blood pressure medicines such as Imdur, ISMO, Isordil, Monoket and Sorbitrate are incompatible with Viagra.

Erythromycin, Nizoral, Sporanox, Tagamet, AIDS medicines such as ritonavir or saquinavir and grapefruit or grapefruit juice may increase blood levels of Viagra.

Rifampin and St. John's wort are expected to reduce blood levels of this medicine.

Taking Viagra and Norvasc (amlodipine) together might lower blood pressure more than expected.

It's possible that flavonoids found in the herb Echinacea affect the enzyme (CYP 3A4) responsible for metabolizing many common drugs. If so, medications such as Viagra could reach higher levels in the body.

The herb St. John's wort might speed elimination of Viagra from the body, which could reduce its effectiveness.

Check with your pharmacist and physician to make sure Viagra is safe in combination with any other medicines and herbs you take.