ORLEX
Clinical safety rating
cautionComprehensive clinical and safety monograph for ORLEX (ORLEX).
Orlistat is a reversible inhibitor of gastric and pancreatic lipases, preventing the hydrolysis of dietary triglycerides into absorbable free fatty acids and monoglycerides. This reduces dietary fat absorption by approximately 30%.
| Metabolism | Primarily metabolized in the gastrointestinal wall and liver via hydrolysis; minimal systemic absorption. Main metabolites are M1 (4-member lactone ring hydrolysis) and M3 (M1 with a cleaved N-formyl leucine moiety). |
| Excretion | Renal: 70% (as unchanged drug and metabolites); Biliary/Fecal: 30% |
| Half-life | Terminal elimination half-life: 4-6 hours; in renal impairment, half-life can extend to >12 hours requiring dose adjustment. |
| Protein binding | 99% primarily to albumin and alpha-1-acid glycoprotein |
| Volume of Distribution | 0.15-0.2 L/kg, indicating confinement to vascular space; correlates with high protein binding. |
| Bioavailability | Oral: 90-100% (extensive absorption); no significant first-pass metabolism. |
| Onset of Action | Oral: 30-60 minutes; IV: within 5 minutes |
| Duration of Action | 4-6 hours; clinical effect parallels plasma concentration. Extended-release formulations may provide up to 12 hours. |
| Molecular Weight | 252.31 Da |
Orally, 1-2 tablets (5-10 mg of hydrocodone equivalent) every 4-6 hours as needed for pain; maximum 12 tablets per day.
| Dosage form | SOLUTION/DROPS |
| Renal impairment | For GFR 30-59 mL/min: administer every 6-8 hours; GFR <30 mL/min: administer every 8-12 hours; avoid use in GFR <15 mL/min. |
| Liver impairment | Child-Pugh Class A: no adjustment; Child-Pugh Class B: reduce dose by 25%; Child-Pugh Class C: avoid use. |
| Pediatric use | Children ≥2 years: 0.1-0.2 mg/kg hydrocodone equivalent orally every 4-6 hours as needed; maximum 10 mg per dose. |
| Geriatric use | Initiate at 50% of adult dose, titrate cautiously; monitor for respiratory depression and constipation. |
| 1st trimester | Avoid in first trimester unless essential; limited human data, animal studies show risk. |
| 2nd trimester | Use only if clearly needed; potential for fetal adverse effects. |
| 3rd trimester | Avoid near term due to risk of neonatal bleeding or other adverse effects. |
Clinical note
Comprehensive clinical and safety monograph for ORLEX (ORLEX).
| Placental transfer | Crosses placenta (human data available); extent unknown but likely significant. |
| Breastfeeding | Excreted into breast milk in small amounts; monitor infant for potential adverse effects; consider risk-benefit. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | ORLEX (codeine/acetaminophen) is contraindicated in all trimesters due to risk of neonatal opioid withdrawal syndrome and acetaminophen hepatotoxicity. First trimester: limited data but no major malformations reported. Second and third trimesters: chronic use may lead to fetal dependence and neonatal abstinence syndrome. During labor, codeine may cause respiratory depression in neonate. |
| Fetal Monitoring | Monitor maternal respiratory rate, sedation level, and bowel function. Fetal monitoring: nonstress test and biophysical profile if chronic use. Neonatal monitoring for withdrawal symptoms (e.g., tremors, irritability, poor feeding) for at least 48 hours after delivery. |
| Fertility Effects | No known significant effect on fertility. Animal studies show no impairment at therapeutic doses. Opioids may affect hormonal regulation but clinical data are limited. |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to active substance or excipientsSevere hepatic impairmentConcurrent use with MAOIs
| Precautions | Hepatotoxicity (rare, but cases of severe liver injury reported), Cholelithiasis (increased risk due to rapid weight loss), Oxalate nephrolithiasis (increased urinary oxalate excretion), Fat-soluble vitamin deficiency (A, D, E, K; supplementation recommended), Gastrointestinal adverse effects (oily spotting, flatus with discharge, fecal urgency, steatorrhea), Interaction with cyclosporine, amiodarone, and antiepileptic drugs |
| Food/Dietary | Avoid alcohol completely; ethanol increases acetaminophen hepatotoxicity and potentiates CNS depression from hydrocodone. No specific food restrictions, but high-fat meals may delay absorption; take on an empty stomach for more consistent effects. Maintain adequate hydration to prevent constipation. |
| Clinical Pearls | ORLEX is a combination of hydrocodone and acetaminophen; monitor for signs of acetaminophen hepatotoxicity, especially in patients with hepatic impairment or chronic alcohol use. Hydrocodone is a prodrug metabolized by CYP2D6; poor metabolizers may have reduced efficacy, while ultrarapid metabolizers risk toxicity. Use with caution in elderly or debilitated patients due to increased fall risk. Avoid concurrent use with other CNS depressants. Prescribe the lowest effective dose for the shortest duration. |
| Patient Advice | Take exactly as prescribed; do not increase dose or frequency without consulting your doctor. · Do not crush, chew, or break extended-release tablets. · Avoid alcohol while taking ORLEX; it increases risk of liver damage and sedation. · Do not drive or operate heavy machinery until you know how ORLEX affects you. · Discontinue use and seek emergency help if you experience signs of allergic reaction (rash, difficulty breathing) or serotonin syndrome (agitation, hallucinations, rapid heart rate, fever). · Store securely out of reach of children; dispose of unused medication properly. · Contact your doctor if pain persists or worsens after a few days. |
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