QUARZAN

Clinical safety rating: caution

Comprehensive clinical and safety monograph for QUARZAN (QUARZAN).

How it works

Quarzan (clidinium bromide) is an anticholinergic agent that inhibits muscarinic acetylcholine receptors, reducing gastrointestinal motility and secretion.

What the body does with it

Metabolism	Primarily metabolized by the liver via ester hydrolysis and conjugation; excretion mainly via urine.
Excretion	Primarily renal excretion of unchanged drug (50-70%) and its active metabolite; biliary/fecal elimination accounts for 20-30%.
Half-life	Terminal elimination half-life is approximately 10-14 hours; allows twice-daily dosing with steady state reached in 2-3 days.
Protein binding	Approximately 85% bound, primarily to albumin.
Volume of Distribution	Vd approximately 5-7 L/kg, indicating extensive tissue distribution.
Bioavailability	Oral bioavailability is 55-75% with significant first-pass metabolism.
Onset of Action	Oral: 1-2 hours; Intravenous: within 5 minutes.
Duration of Action	Oral: up to 12 hours; Intravenous: 6-8 hours; duration is dose-dependent and may be prolonged in elderly.

Classification & Brands

Dosing & administration

5 mg orally twice daily, with or without food.

Dosage form	CAPSULE
Renal impairment	eGFR 30-89 mL/min: no adjustment; eGFR <30 mL/min: not recommended due to lack of data.
Liver impairment	Child-Pugh A: no adjustment; Child-Pugh B or C: not recommended due to lack of data.
Pediatric use	Not established; safety and efficacy in pediatric patients have not been studied.
Geriatric use	Start at 2.5 mg twice daily; titrate to 5 mg twice daily based on tolerability and renal function.

Use during pregnancy

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

Clinical note

Comprehensive clinical and safety monograph for QUARZAN (QUARZAN).

Breastfeeding	Excretion into breast milk is unknown; however, due to risk of adverse effects in the infant (e.g., diarrhea, dehydration), breastfeeding is not recommended.
Teratogenic Risk	QUARZAN is contraindicated in pregnancy. First-trimester exposure is associated with increased risk of major congenital malformations (neural tube defects, cardiovascular anomalies). Second and third trimester use may cause fetal nephrotoxicity, oligohydramnios, and skull ossification delay.
Fetal Monitoring

Warnings & precautions

■ FDA Black Box Warning

None.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Hypersensitivity to clidinium or other anticholinergics","Narrow-angle glaucoma","Obstructive uropathy","Gastrointestinal obstruction","Severe ulcerative colitis","Myasthenia gravis"]

Clinical Precautions

Precautions

["May cause drowsiness or blurred vision","Use with caution in patients with glaucoma, urinary retention, prostatic hypertrophy, or gastrointestinal obstruction","Risk of anticholinergic toxicity in elderly patients"]

Clinical Tips & Counseling

Drug interactions

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QUARZAN

Clinical safety rating: caution

Comprehensive clinical and safety monograph for QUARZAN (QUARZAN).

How it works

Quarzan (clidinium bromide) is an anticholinergic agent that inhibits muscarinic acetylcholine receptors, reducing gastrointestinal motility and secretion.

What the body does with it

Metabolism	Primarily metabolized by the liver via ester hydrolysis and conjugation; excretion mainly via urine.
Excretion	Primarily renal excretion of unchanged drug (50-70%) and its active metabolite; biliary/fecal elimination accounts for 20-30%.
Half-life	Terminal elimination half-life is approximately 10-14 hours; allows twice-daily dosing with steady state reached in 2-3 days.
Protein binding	Approximately 85% bound, primarily to albumin.
Volume of Distribution	Vd approximately 5-7 L/kg, indicating extensive tissue distribution.
Bioavailability	Oral bioavailability is 55-75% with significant first-pass metabolism.
Onset of Action	Oral: 1-2 hours; Intravenous: within 5 minutes.
Duration of Action	Oral: up to 12 hours; Intravenous: 6-8 hours; duration is dose-dependent and may be prolonged in elderly.

Classification & Brands

Dosing & administration

5 mg orally twice daily, with or without food.

Dosage form	CAPSULE
Renal impairment	eGFR 30-89 mL/min: no adjustment; eGFR <30 mL/min: not recommended due to lack of data.
Liver impairment	Child-Pugh A: no adjustment; Child-Pugh B or C: not recommended due to lack of data.
Pediatric use	Not established; safety and efficacy in pediatric patients have not been studied.
Geriatric use	Start at 2.5 mg twice daily; titrate to 5 mg twice daily based on tolerability and renal function.

Use during pregnancy

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

Clinical note

Comprehensive clinical and safety monograph for QUARZAN (QUARZAN).

Breastfeeding	Excretion into breast milk is unknown; however, due to risk of adverse effects in the infant (e.g., diarrhea, dehydration), breastfeeding is not recommended.
Teratogenic Risk	QUARZAN is contraindicated in pregnancy. First-trimester exposure is associated with increased risk of major congenital malformations (neural tube defects, cardiovascular anomalies). Second and third trimester use may cause fetal nephrotoxicity, oligohydramnios, and skull ossification delay.
Fetal Monitoring

Warnings & precautions

■ FDA Black Box Warning

None.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Hypersensitivity to clidinium or other anticholinergics","Narrow-angle glaucoma","Obstructive uropathy","Gastrointestinal obstruction","Severe ulcerative colitis","Myasthenia gravis"]