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Levitra Fact Sheet

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Medication Name (brand): 
Medication Name (clinical): 



Erectile dysfunction


Inhibits the enzyme phosphodiesterase type 5 (PDE5), enhancing the effects of nitric oxide (NO) in initiating and maintaining erection by keeping muscles of the corpus cavernosum relaxed, thereby increasing blood flow into the penis.

  • Supplied as 2.5 mg, 5 mg, 10 mg, and 20 mg orange tablets (breakable).

  • Manufacturer recommends starting at 10 mg about one hour before sexual activity.
  • Many physicians start patients at 5 mg and have them increase to 10 mg if the lower dose is ineffective. Fixed dose studies indicate that 5 mg is almost as effective as higher doses.
  • Maximum plasma concentration is reached in 30 minutes to 2 hours after ingestion (median 1 hour). But if taken after a “high fat meal,” peak plasma levels are decreased by up to 50%.
  • In patients over 65, the starting dose should be no more than 5 mg, and in patients with hepatic impairment starting dose should be no higher than 10 mg.

Side Effects: 
  • Common: Headache, flushing, rhinitis, dyspepsia. Priapism very rare.

  • Cardiovascular issues: Princeton Consensus Panel concluded PDE5 inhibitors are safe for patients with controlled hypertension; mild, stable angina; history of MI; mild valvular disease. Should not be given to patients with more severe cardiovascular disease.

Drug-drug Interactions: 
  • Contraindicated in combination with nitrate drugs, because it potentiates the hypotensive effect. The most commonly prescribed nitrates are sublingual nitroglycerin and Isordil (isosorbide). Can be safely combined with any non-nitrate antihypertensive.

  • Use with caution in combination with alpha-blockers, such as doxazosin (used for benign prostatic hypertrophy).
  • Metabolized by the CYP3A4 enzyme system, so CYP3A4 inhibitors such as cimetidine and erythromycin increase blood levels.
  • Levitra does not affect blood levels of other drugs.


Half-life is 4 hours. Duration of action about 6 hours.


To save money, prescribe 20 mg tablets and have patients split them in half or in quarters as needed. Patients may find Levitra more tolerable if they have available: Tylenol for headache, Sudafed for nasal congestion, and Pepto-bismol for GI distress.

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