Mosby's 2014 Nursing Drug Reference (367 page)
Read Mosby's 2014 Nursing Drug Reference Online
Authors: Linda Skidmore-Roth
(sil-den′a-fill)
Revatio, Viagra
Func. class.:
Erectile agent, antihypertensive, peripheral vasodilator
Chem. class.:
Phosphodiesterase type-5 inhibitor
Do not confuse:
Viagra
/Allegra
Enhances the effect of nitric oxide (NO) by inhibiting phosphodiesterase type 5 (PDE5), which is necessary for degrading cGMP in the corpus cavernosum
Treatment of erectile dysfunction, improvement in exercise ability, pulmonary hypertension
Unlabeled uses:
Sexual dysfunction (women); lower urinary tract symptoms and erectile dysfunction (with alfuzosin); altitude sickness, Raynaud’s disease
Hypersensitivity to this product or nitrates
Precautions:
Pregnancy (B), anatomical penile deformities, sickle cell anemia, leukemia, multiple myeloma, retinitis pigmentosa, bleeding disorders, active peptic ulceration, CV/renal/hepatic disease, multiproduct antihypertensive regimens, geriatric patients
Calculator
• Adult male <65 yr:
PO
50 mg 1 hr before sexual activity; may be increased to 100 mg or decreased to 25 mg; max 1×/day
• Adult ≥65 yr (male):
PO
25 mg as needed about 1 hr before sexual activity
• Adult:
PO
(Child-Pugh A, B) 25 mg, take 1 hr before sexual activity; max 1×/day; CCr <30 ml/min, 25 mg starting dose
• Adult:
PO
20 mg tid; take 4-6 hr apart;
IV BOL
10 mg tid
• Adult:
PO
40 mg 6-8 hr after arriving at 14,272 ft, then 40 mg tid × 6 days
• Adult:
PO
50 mg 60-90 min prior to sexual activity
Available forms:
Tabs 20, 25, 50, 100 mg; sol for inj 10 mg/12.5 ml
•
Erectile dysfunction:
give approximately 1 hr before sexual activity; do not use more than 1×/day, give on empty stomach for better absorption
•
Pulmonary hypertension:
give 3×/day, 4-6 hr apart
CNS:
Headache, flushing, dizziness
, transient global amnesia,
seizures
CV:
MI, sudden death, CV collapse, TIAs, ventricular dysrhythmias, CV hemorrhage
MISC.:
Dyspepsia, nasal congestion, UTI, abnormal vision, diarrhea, rash
,
nonarteritic ischemic optic neuropathy,
hearing loss, priapism,
sickle cell crisis
Rapidly absorbed; bioavailability 40%; metabolized by P45 CYP3A4, 2C9 in the liver (active metabolites); terminal half-life 4 hr; peak 15-30 min; reduced absorption with high-fat meal; excreted in feces, urine
Do not use with nitrates; fatal fall in B/P
Increase:
sildenafil levels—cimetidine, erythromycin, ketoconazole, itraconazole, antiretroviral protease inhibitors, tacrolimus
Decrease:
sildenafil levels—CYP-450 inducers, rifampin, barbiturates, bosentan, carBAMazepine, dexamethasone, phenytoin, nevirapine, rifabutin, troglitazone; antacids
Decrease:
B/P—α-blockers, alcohol, amlodipine, angiotensin II receptor blockers
Increase:
product effect—grapefruit
Decrease:
absorption—high-fat meal
•
Phosphodiesterase type 5 inhibitors with lopinavir/ritonavir (Kaletra):
assess for hypotension, visual changes, prolonged erection, syncope; give only 25 mg q48hr and monitor for adverse reactions
•
Erectile dysfunction prior to use
Any severe loss of vision while taking this or any similar products; products should not be used
Use of organic nitrates that should not be used with this product
•
MI, sudden death, CV collapse:
those with an MI within 6 mo, resting hypotension <90/50, resting hypertension >170/100, fluid depletion should use this product cautiously; may occur right after sexual activity to days afterward
•
Sickle cell crisis (vasoocclusive crisis):
when used for pulmonary hypertension, may require hospitalization
•
Cardiac status, hemodynamic parameters, exercise tolerance in pulmonary hypertension: B/P, pulse
•
Therapeutic response: decreasing pulmonary hypertension/improved exercise tolerance; ability to perform sexually (male)
•
That product does not protect against sexually transmitted diseases, including HIV
•
That product absorption is reduced with a high-fat meal
•
That product should not be used with nitrates in any form
•
That tabs may be split
To notify prescriber immediately and to stop taking product if vision/hearing loss occurs or erection lasts >4 hr
•
That erections lasting >4 hr may occur, report to prescriber immediately
•
Do not use more than 100 mg in 24 hr
Canada only Side effects:
italics
= common;
bold
= life-threatening Nurse Alert
(si-lo′do-seen)
Rapaflo
Func. class.:
Selective α
1
-adrenergic blocker, BPH agent
Chem. class.:
Sulfamoylphenethylamine derivative
Binds preferentially to α
1A
-adrenoceptor subtype located mainly in the prostate
Symptoms of benign prostatic hyperplasia (BPH)
Hypersensitivity, renal failure, hepatic disease
Precautions:
Pregnancy (B), breastfeeding, children, females, geriatric patients, renal/hepatic disease, hypotension, ocular surgery, orthostatic hypotension, prostate cancer, syncope
Calculator
• Adult:
PO
8 mg/day with meal; max 8 mg/day
• Adult:
PO
CCr 30-49 ml/min, 4 mg/day; CCr <30 ml/min, not recommended
Available forms:
Cap 4, 8 mg
•
Give with meal at same time each day
•
Cap may be opened and sprinkled in applesauce
CNS:
Dizziness, headache
, asthenia, insomnia, syncope
CV:
Orthostatic hypotension
EENT:
Nasal congestion, rhinorrhea, sinusitis
GI:
Diarrhea, abdominal pain, jaundice
GU:
Abnormal ejaculation, priapism, urinary incontinence
HEMA:
Purpura
Decreased absorption with high-fat/high-calorie meal, half-life of metabolite 24 hr, metabolized in liver, excreted via urine, extensively protein bound (97%)
Increase:
silodosin effect—CYP3A4 inhibitors (clarithromycin, itraconazole, ritonavir, antiretroviral protease inhibitors, aprepitant, chloramphenicol, conivaptan, dalfopristin, danazol, delavirdine, efavirenz, fosaprepitant, fluconazole, fluvoxaMINE, imatinib, isoniazid, mifepristone, nefazodone, tamoxifen, telithromycin, troleandomycin, voriconazole, zileuton, zafirlukast)
Increase:
silodosin effect—grapefruit juice
Increase:
LFTs
•
Prostatic hyperplasia:
change in urinary patterns at baseline and through
out treatment, testing for prostate cancer, before administration is recommended
•
BUN, uric acid, urodynamic studies (urinary flow rates, residual volume)
•
I&O ratios, weight daily; edema, report weight gain or edema
•
B/P, monitor for orthostatic hypotension
•
Storage at room temp; protect from light and moisture
•
Therapeutic response: decreased symptoms of BPH
•
Not to drive, operate machinery until effect known
•
Not to use with grapefruit juice
•
To take with same meal each day
