Sildenafil Citrate (Viagra) is used to treat impotence in men. Sildenafil citrate increases the body's ability to achieve and maintain an erection during sexual stimulation. This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information. Capsules Chemical Name: SILDENAFIL ( sil-DEN-a-fil) Possible Uses of This Medication This medicine is a phosphodiesterase inhibitor used to treat erectile dysfunction ( ED). Before using Some medicines or medical conditions may interact with this medicine. INFORM YOUR DOCTOR OR PHARMACIST of all prescription and over-the-counter medicine that you are taking. More info... How to take this medication Follow the directions for using this medicine provided by your doctor. More info... Cautions DO NOT EXCEED THE RECOMMENDED DOSE without checking with your doctor. DO NOT TAKE THIS MEDICINE MORE THAN once a day. More info... Possible side effects SIDE EFFECTS that may occur while taking this medicine include headache, flushing, upset stomach, stuffy nose, diarrhea, blurred vision, changes in blue or green vision, or increased light sensitivity. If they continue or are bothersome, check with your doctor. More info... Drug interactions Drug interactions can result in unwanted side effects or prevent a medicine from doing its job.Inform your doctor about all the medicines you take with and without a prescription. Missed Dose Not applicable Storage Store at room temperature away from sunlight and moisture. More info... Other Information DO NOT SHARE THIS MEDICINE with others for whom it was not prescribed. More info...