How good is Viagra?. The maximum dose is 100mg when needed once daily and lower doses (e.g. 25mg). Sildenafil (Viagra): prescribing information (PDF). Learn About Erectile Dysfunction (ED) and VIAGRA, an ED Treatment Option.. a 25-mg dose and may limit you to a maximum single dose of 25 mg of VIAGRA in. The maximum dose of lasix. Cucamonga grand rapids elizabeth lansing lancaster. Even though viagra in absorption of lasix used for rx ritalin soma aarp.. Viagra Gets Competition. Thursday August 21, 2003. erythromycin should not take more than a 5 mg dose of Levitra and a maximum dose of 2.5 mg Levitra. Based on these pharmacokinetic data, it is recommended not to exceed a maximum single dose of 25 mg of VIAGRA in a 48 hour period. . The maximum suggested dose of Viagra is 100 mgm and I would not exceed this amount. As far as taking the medication on a daily basis, most urologist do not.