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
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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 2.55 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)
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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 QT
c 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: 0.52 h.
Metabolism: In liver by CYP3A4.
Elimination: Primarily in feces (9095%).
Half-Life: 45 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.