Classifications: impotence agent; phosphodiesterase (pde) inhibitor; vasodilator; Therapeutic:impotence; pde inhibitor
Pregnancy Category: B
5 mg, 10 mg, 20 mg tablets
Tadalafil is a selective phosphodiesterase (PDE) type 5 inhibitor. PDE type 5 is responsible for degradation of cyclic GMP
in the corpus cavernosum of the penis. Cyclic GMP causes smooth muscle relaxation in the corpus cavernosum, thereby allowing
inflow of blood into the penis.
Tadalafil promotes sustained erection only in the presence of sexual stimulation.
Treatment of erectile dysfunction.
Hypersensitivity to tadalafil, vardenafil, or sildenafil; concurrent administration of nitrates, nitroglycerin, or any alpha-adrenergic
antagonist (other than 0.4 mg q.d. tamsulosin); MI within last 90 d; Class 2 or greater heart failure within last 6 mo;
unstable angina or angina during intercourse; uncontrolled cardiac arrhythmias; nitrate/nitrite therapy; hypotension, uncontrolled
hypertension; retinitis pigmentosa; CVa within last 6 mo; left ventricular outflow obstruction, aortic stenosis; not recommended
for women; lactation.
CAD, risk factors for CVA; renal insufficiency; hepatic impairment, hepatic disease; anatomic deformity of the penis; sickle
cell anemia; multiple myeloma; leukemia; active bleeding or a peptic ulcer; hiatal hernia, GERD; sickle cell disease; retinitis
pigmentosa; hepatitis, cirrhosis; severe renal impairment; older adults; concurrent use with other medicines for penile
dysfunction; pregnancy (category B).
Route & Dosage
Adult: PO 10 mg prior to anticipated sexual activity. May increase to max dose 20 mg/d or reduce to 5 mg/d if needed. If taking ritonavir,
itraconazole, ketoconazole, or voriconazole, max dose 10 mg q72h.
Mild to moderate impairment: max 10 mg/d; not recommended with severe hepatic impairment
Clcr 3050 mL/min: start at 5 mg once daily (max: 10 mg q48h); <30 mL/min: max dose 5 mg
- 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, back pain, asthenia, facial edema, fatigue
, pain. CNS: Headache,
, somnolence, vertigo, hypesthesia, paresthesia. CV:
Angina, chest pain, hypertension, hypotension, MI, orthostatic hypotension, palpitations, syncope, sinus tachycardia. GI:
Dyspepsia, nausea, vomiting, abdominal pain, abnormal liver function tests, diarrhea, loose stools, dysphagia, esophagitis,
, GERD, xerostomia. Metabolic:
Increased GGTP. Musculoskeletal:
Arthralgia, myalgia, neck pain. Respiratory:
Nasal congestion, dyspnea, epistaxis, pharyngitis. Skin:
Rash, pruritus, sweating. Special Senses:
Blurred vision, changes in color vision, conjunctivitis
, eye pain, lacrimation, swelling of eyelids, sudden vision loss. Urogenital:
Spontaneous penile erection.
May potentiate hypotensive effects of ETHANOL
, alfuzosin, doxazosin, prazosin, tamsulosin
(doses >0.4 mg/d), terazosin; erythromycin
(and other MACROLIDES
), indinavir, intraconazole, ketoconazole, PROTEASE INHIBITORS
, ritonavir, saquinavir, voriconazole
may increase levels and toxicity
of tadalafil; barbiturates, bosentan, carbamazepine, dexamethasone, fosphenytoin, nevirapine, rifampin phenytoin, rifabutin, troglitazone
may reduce level and effectiveness of tadalafil. Food: Grapefruit juice
may increase levels and toxicity
Rapidly absorbed, 15% reaches systemic circulation. Onset:
3045 min. Peak:
2 h. Duration:
Up to 36 h. Metabolism:
In liver by CYP3A4. Elimination:
In feces (61%) and urine (39%). Half-Life:
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 per day.
- Note: With moderate renal insufficiency, the maximum recommended dose is 10 mg not more than once in every 48 h.
- Moderate use of alcohol when taking this drug.
- 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; swollen eyelids; muscle aches; painful or prolonged erection (lasting longer than
4 h); skin rash, or itching.