Saturday, March 15, 2008

Alfuzosin:

U.S. BRAND NAMES — Uroxatral®
PHARMACOLOGIC CATEGORY Alpha1 Blocker
DOSING: ADULTS — Benign prostatic hyperplasia (BPH): Oral: 10 mg once daily
DOSING: ELDERLY — Refer to adult dosing.
DOSING: RENAL IMPAIRMENT — Bioavailability and maximum serum concentrations are increased by ~50% with mild, moderate, or severe renal impairment.
Note: Safety has not been evaluated in patients with creatinine clearances <30 mL/minute.
DOSING: HEPATIC IMPAIRMENT Mild hepatic impairment: Use has not been studied.
Moderate or severe hepatic impairment (Child-Pugh class B and C): Clearance is decreased 1/3 to 1/4 and serum concentration is increased three- to fourfold; use is contraindicated.
DOSAGE FORMS — Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Tablet, extended release, as hydrochloride: 10 mg
DOSAGE FORMS: CONCISE Tablet, extended release: Uroxatral™: 10 mg
GENERIC EQUIVALENT AVAILABLE — No
ADMINISTRATION — Tablet should be swallowed whole; do not crush or chew. Administer once daily (with a meal); should be taken at the same time each day.
USE — Treatment of the functional symptoms of benign prostatic hyperplasia (BPH)
ADVERSE REACTIONS SIGNIFICANT 1% to 10%: Central nervous system: Dizziness (6%), fatigue (3%), headache (3%), pain (1% to 2%) Gastrointestinal: Abdominal pain (1% to 2%), constipation (1% to 2%), dyspepsia (1% to 2%), nausea (1% to 2%) Genitourinary: Impotence (1% to 2%) Respiratory: Upper respiratory tract infection (3%), bronchitis (1% to 2%), pharyngitis (1% to 2%), sinusitis (1% to 2%)
<1% (Limited to important or life-threatening): Angina pectoris (pre-existing CAD), angioedema, chest pain, diarrhea, edema, flushing, intraoperative floppy iris syndrome (with cataract surgery), priapism, pruritis, rash, rhinitis, tachycardia, urticaria
CONTRAINDICATIONS — Hypersensitivity to alfuzosin or any component of the formulation; moderate or severe hepatic insufficiency (Child-Pugh class B and C); potent CYP3A4 inhibitors (eg, itraconazole, ketoconazole, ritonavir)
WARNINGS / PRECAUTIONS Concerns related to adverse effects: Angina: Discontinue if symptoms of angina occur or worsen. Floppy iris syndrome: Intraoperative floppy iris syndrome has been observed in cataract surgery patients who were on or were previously treated with alpha1-blockers; causality has not been established and there appears to be no benefit in discontinuing alpha-blocker therapy prior to surgery. Orthostatic hypotension/syncope: May cause significant orthostatic hypotension and syncope, especially with first dose; anticipate a similar effect if therapy is interrupted for a few days, if dosage is rapidly increased, or if another antihypertensive drug (particularly vasodilators) or a PDE5 inhibitor is introduced. Patients should be cautioned about performing hazardous tasks when starting new therapy or adjusting dosage upward.
Disease-related concerns: Hepatic impairment: Use with caution in patients with mild hepatic impairment; not recommended in moderate to severe impairment. Prostate cancer: Should rule out prostatic carcinoma before beginning therapy. Renal impairment: Use with caution in patients with renal impairment.
Special populations: Pediatrics: Safety and efficacy have not been established in children.
Other warning/precautions: Antihypertensive agent: Not intended for use as an antihypertensive drug.
DRUG INTERACTIONS — Substrate of CYP3A4 (major)
CYP3A4 inducers: CYP3A4 inducers may decrease the levels/effects of alfuzosin. Example inducers include aminoglutethimide, carbamazepine, nafcillin, nevirapine, phenobarbital, phenytoin, and rifamycins.
CYP3A4 inhibitors: May increase the levels/effects of alfuzosin. Example inhibitors include azole antifungals, clarithromycin, diclofenac, doxycycline, erythromycin, imatinib, isoniazid, nefazodone, nicardipine, propofol, protease inhibitors, quinidine, telithromycin, and verapamil. Concurrent use of itraconazole, ketoconazole, or ritonavir is contraindicated.
ETHANOL / NUTRITION / HERB INTERACTIONS — Food: Food increases the extent of absorption.
PREGNANCY RISK FACTOR — B (show table)
PREGNANCY IMPLICATIONS — Teratogenic effects were not observed in animal studies; however, alfuzosin is not indicated for use in women.
LACTATION — Not indicated for use in women
DIETARY CONSIDERATIONS — Take following a meal at the same time each day.
PRICING — (data from drugstore.com)Tablet, 24-hour (Uroxatral) 10 mg (30): $76.49
MONITORING PARAMETERS — Urine flow; blood pressure
TOXICOLOGY / OVERDOSE COMPREHENSIVE — Hypotension would be expected in case of overdose. Treatment is symptom-directed and supportive. Dialysis not likely to benefit.
CANADIAN BRAND NAMES — Xatral
INTERNATIONAL BRAND NAMES — Alfetim (HU); Alfusin (IN); Dalfaz (AR, ES, PL); Uroxatral (CL); Uroxatral OD (AR, UY); Uroxatral uno (DE); Xatral (AT, BE, BF, BJ, CA, CH, CI, CN, CZ, DK, ET, FI, FR, GB, GH, GM, GN, IE, IL, IT, KE, LR, MA, ML, MR, MU, MW, NE, NG, NL, SC, SD, SE, SL, SN, TZ, UG, ZA, ZM, ZW); Xatral LP (EC, FR, HK); Xatral OD (BR, CO, CR, DO, GT, HN, MX, NI, PA, PE, PH, PY, SV, VE); Xatral SR (AT, BG, EE, EG, IL, PK, SG); Xatral XL (ID, IL, KR, SG, TH); Xatral XR 10 (SG)
MECHANISM OF ACTION — An antagonist of alpha1-adrenoreceptors in the lower urinary tract. Smooth muscle tone is mediated by the sympathetic nervous stimulation of alpha1-adrenoreceptors, which are abundant in the prostate, prostatic capsule, prostatic urethra, and bladder neck. Blockade of these adrenoreceptors can cause smooth muscles in the bladder neck and prostate to relax, resulting in an improvement in urine flow rate and a reduction in symptoms of BPH.
PHARMACODYNAMICS / KINETICS Absorption: Decreased 50% under fasting conditions
Distribution: Vd: 3.2 L/kg
Protein binding: 82% to 90%
Metabolism: Hepatic, primarily via CYP3A4; metabolism includes oxidation, O-demethylation, and N-dealkylation; forms metabolites (inactive)
Bioavailability: 49% following a meal
Half-life elimination: 10 hours
Time to peak, plasma: 8 hours following a meal
Excretion: Feces (69%); urine (24%)
PATIENT INFORMATION — Do not take any new medication during therapy without consulting prescriber. Take exactly as directed, with a meal at the same time each day. Swallow tablet whole; do not crush or chew. May cause drowsiness, dizziness, impaired judgment (use caution when driving or engaging in tasks that require alertness until response to drug is known), or postural hypotension (use caution when rising from sitting or lying position or when climbing stairs). Report unusual chest pain, respiratory difficulty, or any persistent adverse reactions.

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