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Indications

REMS


Contraind./Precautions

Contraindicated in:

Use Cautiously in:

Adv. Reactions/Side Effects

Derm: flushing

EENT: HEARING LOSS, rhinitis, sinusitis, VISION LOSS

GI: dyspepsia, nausea

GU: priapism

Neuro: headache, amnesia, dizziness

Misc: flu syndrome

Interactions

Drug-drug:

Availability

(Generic available)

Route/Dosage

Tablets

Hepatic Impairment

Orally Disintegrating Tablets

Action

  • Increases cyclic guanosine monophosphate (cGMP) levels by inhibiting phosphodiesterase type 5, an enzyme responsible for the breakdown of cGMP. cGMP produces smooth muscle relaxation of the corpus cavernosum, which in turn promotes increased blood flow and subsequent erection.
Therapeutic effects:
  • Enhanced blood flow to the corpus cavernosum and erection sufficient to allow sexual intercourse.
  • Requires sexual stimulation.

Classifications

Therapeutic Classification: erectile dysfunction agents

Pharmacologic Classification: phosphodiesterase type 5 inhibitors

Pharmacokinetics

Absorption: 15% absorbed following oral administration; absorption is rapid.

Distribution: Extensive tissue distribution; penetrates semen.

Protein Binding: 95%.

Metabolism/Excretion: Mostly metabolized by the liver via the CYP3A4 isoenzyme and to a lesser extent by the CYP2C isoenzyme. M1 metabolite has anti-erectile dysfunction activity. Parent drug and metabolites are mostly excreted in feces. 2–6% renally eliminated.

Half-Life: 4–6 hr.

Canadian Brand Names

Levitra, Staxyn

Time/Action Profile

ROUTEONSETPEAKDURATION
POrapid0.5–2 hr4 hr



Patient/Family Teaching

Pronunciation

var-DEN-a-fil