Some medications should not be taken with sildenafil. This medicine works best when you take it on an empty stomach an hour before sex. Such patients must not apply any out-of-pocket expenses incurred using this Savings Offer toward any government insurance benefit out-of-pocket spending calculations, such as Medicare Part D true out-of-pocket TrOOP costs You are responsible for reporting use of this Savings Offer to any private insurer, health plan, or other third party who pays for or reimburses any part of the prescription filled using this Savings Offer, as may be required. This can happen if you are sick with fever, diarrhea, or vomiting; sweat a lot; or do not drink enough liquids. Do not take more or less of it or take it more often than prescribed by your doctor. These small differences affect the way each medication works, such as how quickly it takes effect and wears off, and the possible side effects. These medicines are called PDE5 inhibitors.CR Best Buy Drugs recommends you review your medications with your doctor or pharmacist because antidepressants, blood pressure medicines, heartburn drugs, . If you have certain health conditions or are taking certain medications, your doctor may tell you to take sildenafil less often. You can take sildenafil with or without food. However, if . If you sense your doctor is uncomfortable talking about ED, ask for a referral to a urologist—a specialist trained to treat conditions related to the urinary tract and male reproductive system. For more on diagnosing and treating ED, read What to do About .