Follow the manufacturer’s directions to use and clean the oral syringe. Please expect up to 4 to 6 weeks for reimbursement. Do not take more or less of it or take it more often than prescribed by your doctor. If you have certain health conditions or are taking certain medications, your doctor may tell you to take sildenafil less often. Data shared with Viatris will be aggregated and de-identified; it will be combined with data related to other Savings Offer redemptions and will not identify you Viatris reserves the right to rescind, revoke, or amend this Savings Offer without notice No membership fees. Talk to your doctor about eating grapefruit and drinking grapefruit juice while taking this medicine. If you are taking sildenafil to treat PAH, you will probably take sildenafil three times a day with or without food.Safety & Possible Side Effects. take any medicines called nitrates, often prescribed for chest pain, or guanylate cyclase stimulators like Adempas (riociguat) for pulmonary hypertension. Your blood pressure could drop to an unsafe level. are allergic to sildenafil, as contained in VIAGRA and REVATIO, or any of the ingredients in VIAGRA. For Erectile Dysfunction “I have been taking Viagra for about 15 years. It works great for me with minimal side effects. One 50 mg tablet turns me into a raging bull for about 18 hours. The key is to always take it on an empty stomach. I discovered that if my body is low in salt, the Viagra does not work as well.  · Viagra comes as an oral tablet that contains the active drug sildenafil. Sildenafil is also available in generic form. Viagra is classified as a phosphodiesterase type 5 (PDE5) inhibitor.