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VARDENAFIL HYDROCHLORIDE

Medical Diagnosis and Drugs, Medications
VARDENAFIL HYDROCHLORIDE
(var-den'a-fil hy-dro-chlo'ride)
Levitra
Classifications: impotence agent; phosphodiesterase (pde) inhibitor; vasodilator;
Therapeutic:impotence; pde inhibitor; vasodilator
Prototype: Sildenafil
Pregnancy Category: B

Availability

2.5 mg, 5 mg, 10 mg, 20 mg tablets

Action

Phosphodiesterases-5 (PDE5) is an enzyme that speeds up the degradation of cyclic guanosine monophosphate (cGMP), an enzyme needed to cause and maintain increased blood flow into the penis necessary for an erection. Vardenafil is a PDE5 inhibitor.

Therapeutic Effect

It enhances erectile function by increasing the amount of cGMP in the penis.

Uses

Treatment of erectile dysfunction.

Contraindications

Hypersensitivity to vardenafil or sildenafil; concurrent administration of nitrates or nitroglycerin; QT prolongation, renal failure, severe renal impairment; retinitis pigmentosa; not recommended for women or children; lactation.

Cautious Use

CAD, MI, or stroke within 6 mo; hypotension, or hypertension; risk factors for CVA; anatomic deformity of the penis; subaortic stenosis; sickle cell anemia, leukemia; multiple myeloma; leukemia; coagulopathy; active bleeding or a peptic ulcer; coagulopathy; GERD; hepatitis, cirrhosis; older adults; concurrent use with other medicines for penile dysfunction; pregnancy (category B).

Route & Dosage

Erectile Dysfunction
Adult: PO 10 mg approximately 60 min before sexual activity. May increase to max 20 mg/d if needed. If taking ritonavir, max dose is 2.5 mg/72 h. If taking erythromycin, indinavir, itraconazole, ketoconazole, max dose is 2.5–5 mg/24 h.
Geriatric: PO Start with 5 mg 60 min before sexual activity (max: 20 mg/d)

Hepatic Impairment
Moderate impairment: reduce dose to 5 mg (max: 10 mg/d)

Administration

Oral
  • Take approximately 1 h before expected intercourse, but preferably not after a heavy or high-fat meal.
  • Store at 15°–30° C (59°–86° F).

Adverse Effects (≥1%)

Body as a Whole: Flushing, flu-like syndrome, back pain, anaphylactoid reactions, asthenia, facial edema, pain, paresthesias. CNS: Headache, dizziness, insomnia, somnolence, vertigo. CV: Angina, hypertension, hypotension, MI, orthostatic hypotension, palpitations, syncope, sinus tachycardia. GI: Dyspepsia, nausea, vomiting, abdominal pain, abnormal liver function tests, diarrhea, dysphagia, esophagitis, gastritis, GERD, xerostomia. Metabolic: Increased creatine kinase. Musculoskeletal: Arthralgia, myalgia, hypertonia, hyperesthesia. Respiratory: Rhinitis, sinusitis, dyspnea, epistaxis, pharyngitis. Skin: Photosensitivity, rash, pruritus, sweating. Special Senses: Tinnitus, sudden vision loss, blurred vision, changes in color vision. Urogenital: Ejaculation dysfunction.

Interactions

Drug: May potentiate hypotensive effects of nitrates, alfuzosin, doxazosin, prazosin, tamsulosin, terazosin; amiodarone, dofetilide, procainamide, quinidine, sotalol may increase QTc interval leading to arrhythmias; erythromycin (and other macrolides), indinavir, itraconazole, ketoconazole, PROTEASE INHIBITORS, ritonavir, voriconazole may increase level and toxicity of vardenafil.

Pharmacokinetics

Absorption: Rapidly absorbed, 15% reaches systemic circulation. Onset: Within 1 h. Peak: 0.5–2 h. Metabolism: In liver by CYP3A4. Elimination: Primarily in feces (90–95%). Half-Life: 4–5 h.

Nursing Implications

Assessment & Drug Effects

  • Monitor CV status and report angina or other S&S of cardiac dysfunction.
  • Lab tests: Baseline and periodic LFTs.

Patient & Family Education

  • Do not take more than once a day and never take more than the prescribed dose.
  • Do not take this drug without consulting physician if you are taking drugs called "alpha blockers" or "nitrates" or any other drugs for high blood pressure, chest pain, or enlarged prostate.
  • Report promptly any of the following: palpitations, chest pain, back pain, difficulty breathing, or shortness of breath; dizziness or fainting; changes in vision; dizziness; swollen eyelids; muscle aches; painful or prolonged erection (lasting longer than 4 h); skin rash, or itching.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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