Protein binding is independent of total drug concentrations. However, others work on a cash-pay basis and don’t partner with insurance companies. This is consistent with ritonavir’s marked effects on a broad range of P substrates. The following nonprescription or herbal products may interact with sildenafil: cimetidine Tagamet HB , St. Figure 6 shows that regardless of the baseline levels of function, subsequent function in patients treated with VIAGRA was better than that seen in patients treated with placebo.The Savings Offer and Program expire on 12/31/ For further information, call , visit , or write: Viatris Inc., P.O. Box , Mission, KS If your pharmacy does not participate, you may be able to submit a request for a rebate in connection with this Savings Offer. Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Sildenafil (Liqrev, Revatio) is used to improve the ability to exercise in adults (Liqrev, Revatio) and children 1 year of age and older (Revatio) with pulmonary arterial hypertension (PAH; high blood pressure in the vessels carrying blood to the . There is also a generic version of Viagra available, under the name sildenafil, in 25mg, 50mg, and mg strengths. 3. Downsides (Viagra) for ED, do not take it more than once a day. Take an hour before sexual stimulation (range 30 minutes to 4 hours). Always buy your ED medications from a reputable supplier as there are a lot of.