UROXATRAL

Clinical safety rating: caution

Comprehensive clinical and safety monograph for UROXATRAL (UROXATRAL).

How it works

Selective antagonist of postsynaptic alpha1A-adrenoceptors in the prostate, bladder base, and prostatic urethra, leading to relaxation of smooth muscle and improved urinary flow.

What the body does with it

Metabolism	Primarily hepatic via CYP3A4, with minor contributions from CYP1A2, CYP2D6, and CYP2C8. Extensive first-pass metabolism.
Excretion	After oral administration, approximately 11% of the dose is excreted unchanged in urine, while 49% is excreted as metabolites in urine and 22% in feces. Overall, renal elimination accounts for about 60% of total clearance.
Half-life	The terminal elimination half-life is approximately 5 to 9 hours in healthy young subjects, and 6 to 10 hours in elderly patients. This supports once-daily dosing, with steady state achieved after 3-5 days.
Protein binding	Alfuzosin is approximately 82-90% bound to plasma proteins, primarily to alpha-1-acid glycoprotein (AAG). Binding is concentration-independent within therapeutic range.
Volume of Distribution	The volume of distribution after oral administration is about 2.5 L/kg, indicating extensive distribution into extravascular tissues. This large Vd contributes to its prolonged duration of action.
Bioavailability	The absolute oral bioavailability of alfuzosin is approximately 49% (range 44-53%) when taken under fed conditions. Food increases Cmax by about 50% and AUC by 20-30% compared to fasting; therefore, it should be taken with food.
Onset of Action	The onset of clinical effect (improvement in urinary symptoms) occurs within 1 to 2 weeks of starting oral therapy, as determined by the International Prostate Symptom Score (IPSS). The peak effect is observed after 4-6 weeks.
Duration of Action	The duration of action supports once-daily dosing. After discontinuation, symptom relief may persist for several days but gradual return to baseline is expected within 1-2 weeks.

Classification & Brands

Dosing & administration

10 mg orally once daily, immediately after the same meal each day.

Dosage form	TABLET, EXTENDED RELEASE
Renal impairment	No dosage adjustment required for mild to moderate renal impairment (CrCl ≥30 mL/min). For severe renal impairment (CrCl <30 mL/min), contraindicated.
Liver impairment	Contraindicated in moderate to severe hepatic impairment (Child-Pugh class B or C). No data for mild impairment (Child-Pugh A); use with caution.
Pediatric use	Not approved; safety and efficacy not established in pediatric patients.
Geriatric use	No specific dosage adjustment required; monitor for orthostatic hypotension and dizziness.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for UROXATRAL (UROXATRAL).

Breastfeeding	Alfuzosin is excreted in rat milk; no human data. M/P ratio unknown. Due to potential for adverse effects in nursing infants, caution is advised; consider discontinuing breastfeeding or drug based on importance to mother.
Teratogenic Risk	UROXATRAL (alfuzosin HCl) is classified as FDA Pregnancy Category B. Animal studies have not shown fetal harm, but no adequate human studies exist. Risk cannot be ruled out, especially in the first trimester. Use only if clearly needed.
Fetal Monitoring

Warnings & precautions

■ FDA Black Box Warning

None

Side Effect Profile

Serious Effects

Absolute Contraindications

["Hypersensitivity to alfuzosin or any component of the formulation","Concomitant use with strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, ritonavir)","Moderate to severe hepatic impairment (Child-Pugh B and C)"]

Clinical Precautions

Precautions

["Orthostatic hypotension and syncope (especially with dose escalation or use with other alpha-blockers or antihypertensives)","Use with caution in patients with renal impairment (CrCl < 30 mL/min)","Intraoperative floppy iris syndrome (IFIS) during cataract surgery","Priapism (rare)","Hepatic impairment"]

Clinical Tips & Counseling

Drug interactions

Loading safety data…

UROXATRAL

Clinical safety rating: caution

Comprehensive clinical and safety monograph for UROXATRAL (UROXATRAL).

How it works

Selective antagonist of postsynaptic alpha1A-adrenoceptors in the prostate, bladder base, and prostatic urethra, leading to relaxation of smooth muscle and improved urinary flow.

What the body does with it

Metabolism	Primarily hepatic via CYP3A4, with minor contributions from CYP1A2, CYP2D6, and CYP2C8. Extensive first-pass metabolism.
Excretion	After oral administration, approximately 11% of the dose is excreted unchanged in urine, while 49% is excreted as metabolites in urine and 22% in feces. Overall, renal elimination accounts for about 60% of total clearance.
Half-life	The terminal elimination half-life is approximately 5 to 9 hours in healthy young subjects, and 6 to 10 hours in elderly patients. This supports once-daily dosing, with steady state achieved after 3-5 days.
Protein binding	Alfuzosin is approximately 82-90% bound to plasma proteins, primarily to alpha-1-acid glycoprotein (AAG). Binding is concentration-independent within therapeutic range.
Volume of Distribution	The volume of distribution after oral administration is about 2.5 L/kg, indicating extensive distribution into extravascular tissues. This large Vd contributes to its prolonged duration of action.
Bioavailability	The absolute oral bioavailability of alfuzosin is approximately 49% (range 44-53%) when taken under fed conditions. Food increases Cmax by about 50% and AUC by 20-30% compared to fasting; therefore, it should be taken with food.
Onset of Action	The onset of clinical effect (improvement in urinary symptoms) occurs within 1 to 2 weeks of starting oral therapy, as determined by the International Prostate Symptom Score (IPSS). The peak effect is observed after 4-6 weeks.
Duration of Action	The duration of action supports once-daily dosing. After discontinuation, symptom relief may persist for several days but gradual return to baseline is expected within 1-2 weeks.

Classification & Brands

Dosing & administration

10 mg orally once daily, immediately after the same meal each day.

Dosage form	TABLET, EXTENDED RELEASE
Renal impairment	No dosage adjustment required for mild to moderate renal impairment (CrCl ≥30 mL/min). For severe renal impairment (CrCl <30 mL/min), contraindicated.
Liver impairment	Contraindicated in moderate to severe hepatic impairment (Child-Pugh class B or C). No data for mild impairment (Child-Pugh A); use with caution.
Pediatric use	Not approved; safety and efficacy not established in pediatric patients.
Geriatric use	No specific dosage adjustment required; monitor for orthostatic hypotension and dizziness.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for UROXATRAL (UROXATRAL).

Breastfeeding	Alfuzosin is excreted in rat milk; no human data. M/P ratio unknown. Due to potential for adverse effects in nursing infants, caution is advised; consider discontinuing breastfeeding or drug based on importance to mother.
Teratogenic Risk	UROXATRAL (alfuzosin HCl) is classified as FDA Pregnancy Category B. Animal studies have not shown fetal harm, but no adequate human studies exist. Risk cannot be ruled out, especially in the first trimester. Use only if clearly needed.
Fetal Monitoring

Warnings & precautions

■ FDA Black Box Warning

None

Side Effect Profile

Serious Effects

Absolute Contraindications

Clinical Precautions

Precautions

Clinical Tips & Counseling

Drug interactions

Loading safety data…