Read Mosby's 2014 Nursing Drug Reference Online
Authors: Linda Skidmore-Roth
Mosby's 2014 Nursing Drug Reference (414 page)
Canada only Side effects:
italics
= common;
bold
= life-threatening 
Nurse Alert
(var-den′a-fil)
Levitra, Staxyn
Func. class.:
Erectile dysfunction agent
Chem. class.:
Phosphodiesterase type 5 inhibitor
Inhibits phosphodiesterase type 5 (PDE5), enhances erectile function by increasing the amount of cGMP, which in turn causes smooth muscle relaxation and increased blood flow into the corpus cavernosum
Treatment of erectile dysfunction
Hypersensitivity, coadministration of α-blockers or nitrates, renal failure, congenital or acquired QT prolongation
Precautions:
Pregnancy (B); not indicated for women, children, or newborns; hepatic impairment, retinitis pigmentosa, anatomical penile deformities, sickle cell anemia, leukemia, multiple myeloma, bleeding disorders, active peptic ulceration, CV/renal disease
Calculator
• Adult:
PO
10 mg taken 1 hr before sexual activity; dose may be reduced to 5 mg or increased to max 20 mg; max dosing frequency once daily; orally disintegrating tab 10 mg 60 min before sexual activity; do not use with potent CYP3A4 inhibitors
• Geriatric >65 yr:
PO
5 mg initially, titrated as needed/tolerated
• Adult:
PO
(Child-Pugh B) 5 mg, max 10 mg/day
•
Ritonavir, max 2.5 mg q72hr; for indinavir, ketoconazole 400 mg/day and itraconazole 400 mg/day, max 2.5 mg/day; for ketoconazole 200 mg/day, itracon
azole 200 mg/day and erythromycin max 5 mg/day
Available forms:
Tabs 2.5, 5, 10, 20 mg; orally disintegrating tab 10 mg
•
Approximately 1 hr before sexual activity; do not use more than once daily; orally disintegrating tabs are not interchangeable with film-coated tabs
•
Without regard to food; avoid taking with high-fat meal
•
Oral disintegrating tab:
place on tongue, allow to dissolve, do not use water
CNS:
Headache, flushing, dizziness, insomnia
,
seizures,
transient global amnesia
CV:
Hypertension,
MI, CV collapse,
chest pain
EENT:
Conjunctivitis, tinnitus, photophobia, diminished vision, glaucoma, hearing loss
GU:
Abnormal ejaculation, priapism
MISC:
Rash, GERD, GGTP increased,
NAION (nonarteritic ischemic optic neuropathy),
dyspepsia
MS:
Myalgia, arthralgia, neck pain
RESP:
Rhinitis, sinusitis, dyspnea, pharyngitis, epistaxis
Rapidly absorbed, bioavailability 15%, protein binding 95%, metabolized by liver, terminal half-life 4-5 hr, onset 20 min, peak 1/2-1½ hr, duration <5 hr, reduced absorption with high-fat meal, primarily excreted in feces (91%-95%)
Do not use with nitrates because of unsafe decrease in B/P, which could result in MI or stroke
Serious dysrhythmias: class IA/III antiarrhythmics, clarithromycin, droperidol, procainamide, quiNIDine, quinolones; do not use concurrently
Increase:
hypotension—α-blockers, protease inhibitors, metoprolol, NIFEdipine, alcohol, amLODIPine, angiotensin II receptor blockers; do not use concurrently
Increase:
vardenafil levels—erythromycin, azole antifungals (ketoconazole, itraconazole), cimetidine, antiretroviral protease inhibitors
Decrease:
absorption—high-fat meal
Increase:
CK
•
Erectile dysfunction and cause before treatment
Any severe loss of vision while taking this or similar products; products should not be used
Use of organic nitrates that should not be used with this product
•
That product does not protect against STDs, including HIV
•
That product absorption is reduced with high-fat meal
•
That product should not be used with nitrates in any form; to inform physician of all medications being taken
•
That product has no effect in the absence of sexual stimulation; that patient should seek immediate medical attention if erections last >4 hr
To notify prescriber immediately and stop taking product if vision loss occurs
Canada only Side effects:
italics
= common;
bold
= life-threatening Nurse Alert