ORLEX HC

Clinical safety rating: caution

Comprehensive clinical and safety monograph for ORLEX HC (ORLEX HC).

How it works

Hydrocodone is a full opioid agonist with relative selectivity for mu-opioid receptors, though it can bind to other opioid receptors at higher doses. Its analgesic effects are mediated via modulation of nociceptive pathways in the CNS. Homatropine is an anticholinergic agent that reduces excessive respiratory tract secretions by blocking muscarinic receptors.

What the body does with it

Metabolism	Hydrocodone is metabolized primarily via CYP3A4 and CYP2D6 to hydromorphone (active) and norhydrocodone (inactive). Homatropine is metabolized via hepatic enzymes, exact pathways not well characterized.
Excretion	ORLEX HC contains Hydrocodone and Homatropine. Hydrocodone: primarily renal elimination (~85% as metabolites, ~5% unchanged). Homatropine: biliary/fecal (up to 70%) and renal (30%).
Half-life	Hydrocodone: terminal half-life 3.8-5.6 hours (mean ~4.5 h) in adults; clinically, steady state in ~1-2 days. Homatropine: ~8-12 hours.
Protein binding	Hydrocodone: ~20-30% bound, primarily to albumin. Homatropine: ~15% bound to albumin.
Volume of Distribution	Hydrocodone: 3.3-4.7 L/kg (extensive tissue distribution). Homatropine: ~1-2 L/kg.
Bioavailability	Hydrocodone: oral bioavailability ~50-70% (first-pass effect). Homatropine: oral bioavailability ~10-20% (poor absorption and first-pass).
Onset of Action	Hydrocodone: oral onset 10-30 minutes. Homatropine: oral onset 30-60 minutes.
Duration of Action	Hydrocodone: 4-6 hours (analgesic). Homatropine: up to 6 hours (anticholinergic).

Classification & Brands

Dosing & administration

1 capsule (hydrocortisone 5 mg, phenylephrine 5 mg, chlorpheniramine 4 mg) orally every 4-6 hours as needed, not exceeding 6 capsules per day.

Dosage form	SOLUTION/DROPS
Renal impairment	No specific dose adjustment recommended. Use with caution in severe renal impairment (eGFR <30 mL/min/1.73m²) due to risk of phenylephrine accumulation and hypertension.
Liver impairment	No specific dose adjustment recommended. Use with caution in severe hepatic impairment (Child-Pugh Class C) due to potential increased exposure to hydrocortisone and chlorpheniramine.
Pediatric use	Not recommended for children under 12 years. For ages 12-17: 1 capsule orally every 4-6 hours, max 6 capsules/day.
Geriatric use	Initiate at lowest effective dose (e.g., 1 capsule every 6 hours) and monitor for anticholinergic effects (chlorpheniramine) and hypertension (phenylephrine). Avoid in patients with uncontrolled hypertension or narrow-angle glaucoma.

Use during pregnancy

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

Clinical note

Comprehensive clinical and safety monograph for ORLEX HC (ORLEX HC).

Breastfeeding	Small amounts excreted in breast milk; M/P ratio unknown. Avoid high doses; monitor for infant adrenal suppression.
Teratogenic Risk	First trimester: Cleft lip/palate, neural tube defects; late pregnancy: premature closure of ductus arteriosus, oligohydramnios, fetal renal impairment; third trimester: neonatal adrenal suppression.
Fetal Monitoring	Monitor fetal growth and amniotic fluid volume via ultrasound; assess ductus arteriosus flow in third trimester; maternal blood pressure and glucose.

Warnings & precautions

■ FDA Black Box Warning

Risks of addiction, abuse, misuse; life-threatening respiratory depression; accidental ingestion (especially fatal in children); neonatal opioid withdrawal syndrome with prolonged use during pregnancy; risks from concomitant use with benzodiazepines or other CNS depressants; risk of medication errors due to multiple strengths and formulations.

Side Effect Profile

Serious Effects

Absolute Contraindications

Hypersensitivity to hydrocodone, homatropine, or any component; patients with respiratory depression (in absence of resuscitative equipment); acute or severe bronchial asthma; hypercapnia; paralytic ileus; known or suspected GI obstruction; concurrent MAOI use or within 14 days; children under 18 years (due to risk of fatal respiratory depression).

Clinical Precautions

Precautions

Respiratory depression; drug dependence and abuse; head injury/increased intracranial pressure; acute abdominal conditions; concurrent use with CNS depressants; elderly/debilitated patients; severe renal or hepatic impairment; hypothyroidism; Addison's disease; prostatic hyperplasia; urinary retention; pregnancy; lactation.

Clinical Tips & Counseling

Drug interactions

Loading safety data…

ORLEX HC

Clinical safety rating: caution

Comprehensive clinical and safety monograph for ORLEX HC (ORLEX HC).

How it works

What the body does with it

Metabolism	Hydrocodone is metabolized primarily via CYP3A4 and CYP2D6 to hydromorphone (active) and norhydrocodone (inactive). Homatropine is metabolized via hepatic enzymes, exact pathways not well characterized.
Excretion	ORLEX HC contains Hydrocodone and Homatropine. Hydrocodone: primarily renal elimination (~85% as metabolites, ~5% unchanged). Homatropine: biliary/fecal (up to 70%) and renal (30%).
Half-life	Hydrocodone: terminal half-life 3.8-5.6 hours (mean ~4.5 h) in adults; clinically, steady state in ~1-2 days. Homatropine: ~8-12 hours.
Protein binding	Hydrocodone: ~20-30% bound, primarily to albumin. Homatropine: ~15% bound to albumin.
Volume of Distribution	Hydrocodone: 3.3-4.7 L/kg (extensive tissue distribution). Homatropine: ~1-2 L/kg.
Bioavailability	Hydrocodone: oral bioavailability ~50-70% (first-pass effect). Homatropine: oral bioavailability ~10-20% (poor absorption and first-pass).
Onset of Action	Hydrocodone: oral onset 10-30 minutes. Homatropine: oral onset 30-60 minutes.
Duration of Action	Hydrocodone: 4-6 hours (analgesic). Homatropine: up to 6 hours (anticholinergic).

Classification & Brands

Dosing & administration

1 capsule (hydrocortisone 5 mg, phenylephrine 5 mg, chlorpheniramine 4 mg) orally every 4-6 hours as needed, not exceeding 6 capsules per day.

Dosage form	SOLUTION/DROPS
Renal impairment	No specific dose adjustment recommended. Use with caution in severe renal impairment (eGFR <30 mL/min/1.73m²) due to risk of phenylephrine accumulation and hypertension.
Liver impairment	No specific dose adjustment recommended. Use with caution in severe hepatic impairment (Child-Pugh Class C) due to potential increased exposure to hydrocortisone and chlorpheniramine.
Pediatric use	Not recommended for children under 12 years. For ages 12-17: 1 capsule orally every 4-6 hours, max 6 capsules/day.
Geriatric use	Initiate at lowest effective dose (e.g., 1 capsule every 6 hours) and monitor for anticholinergic effects (chlorpheniramine) and hypertension (phenylephrine). Avoid in patients with uncontrolled hypertension or narrow-angle glaucoma.

Use during pregnancy

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

Clinical note

Comprehensive clinical and safety monograph for ORLEX HC (ORLEX HC).

Breastfeeding	Small amounts excreted in breast milk; M/P ratio unknown. Avoid high doses; monitor for infant adrenal suppression.
Teratogenic Risk	First trimester: Cleft lip/palate, neural tube defects; late pregnancy: premature closure of ductus arteriosus, oligohydramnios, fetal renal impairment; third trimester: neonatal adrenal suppression.
Fetal Monitoring	Monitor fetal growth and amniotic fluid volume via ultrasound; assess ductus arteriosus flow in third trimester; maternal blood pressure and glucose.