Viagra Dosage

by on July 15, 2012

Viagra (sildenafil) is supplied in tablet form with three dosages (25 mg, 50 mg, and 100 mg). Your healthcare provider will give you a Viagra dosage that is most effective for you. Normally, your doctor will evaluate your condition and prescribe a dosing schedule based on a number of factors that include your age, other existing or past medical conditions, and other medications currently taken.

As with other medications, do not adjust your dose unless specifically instructed by your healthcare provider.

Treatment of Erectile Dysfunction

The recommended starting dose of Viagra for men is 50 mg, taken as needed. It should be taken at least 1 hour, although it may be taken 30 minutes up to 4 hours before anticipated sexual activity. If you are not getting a satisfying erection, your dosage may be increased up to a maximum of 100 mg. If you experience any side effects, the dose may be decreased to 25 mg.

The maximum recommended dosage is single dose per day.

Use in Special Populations

Use in Older Adults

Men older than 65 years may be more sensitive to the effects of Viagra. Clinical studies show that the plasma levels of Viagra in some older men is up by 40 percent compared to younger users. Therefore, older men should start at the lowest effective dose, usually 25 mg.

Individuals with Liver and Kidney Impairment

People with severe hepatic or renal impairment may require lower doses of Viagra. Your healthcare provider may start you at 25 mg. The dose may be adjusted depending on your response to treatment.

Inform your healthcare provider if you have history or existing kidney or liver impairment before taking this medication.

Individuals Taking Certain Medications

Concomitant use of Viagra with certain medications can lead to drug interactions. Some of the medications that can affect the breakdown and excretion of Viagra include erythromycin, ketoconazole, itraconazole, saquinavir, and ritonavir. These medications may increase the risk of side effects. Individuals taking these medications are usually given a lower starting dose of Viagra at 25 mg.

Similarly, individuals taking medications for high blood pressure or prostate problems and taking alpha blockers are also given a lower dose of Viagra.

Meanwhile, Viagra is contraindicated to patients taking nitrates. This is because Viagra potentiates the blood pressure-lowering effects of nitrates.

Some medications may also interact with Viagra. Be sure to inform your healthcare provider of all the drugs you normally take for necessary dose adjustments.