Prior to using Flomax, it is important that one discusses possible side effects that can result from Flomax use with one’s medical provider and pharmacist. Side effects that can result from Flomax use include nausea, headache, dizziness, low blood pressure, gastrointestinal symptoms, and fainting. Blurry vision and trouble sleeping have also been reported after Flomax use. Side effects of Flomax sexually include decreased libido. People who have a known hypersensitivity or allergy to Flomax or ingredients in the medication should not use it. Flomax and alcohol should not be used together.