CO-LAV
Clinical safety rating
cautionComprehensive clinical and safety monograph for CO-LAV (CO-LAV).
CO-LAV is a combination of codeine and acetylsalicylic acid (aspirin). Codeine is a prodrug that is metabolized to morphine, which acts as an agonist at mu-opioid receptors, producing analgesia. Aspirin irreversibly inhibits cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), reducing prostaglandin synthesis and providing analgesic, antipyretic, and anti-inflammatory effects.
| Metabolism | Codeine is metabolized via CYP2D6 to morphine (active), and via CYP3A4 to norcodeine, with further glucuronidation. Aspirin is rapidly hydrolyzed to salicylate by esterases in the gastrointestinal tract and liver; salicylate is primarily metabolized by conjugation with glycine (salicyluric acid) and glucuronic acid, with minor oxidation. |
| Excretion | CO-LAV is not a recognized drug. Please check the drug name. |
| Half-life | Unknown |
| Protein binding | Unknown |
| Volume of Distribution | Unknown |
| Bioavailability | Unknown |
| Onset of Action | Unknown |
| Duration of Action | Unknown |
| Molecular Weight | 469.4 |
Adults: 1 tablet (trimethoprim 80 mg/sulfamethoxazole 400 mg) orally twice daily for 5-7 days; for Pneumocystis jirovecii pneumonia, 2 tablets (160 mg/800 mg) orally every 6 hours for 21 days.
| Dosage form | FOR SUSPENSION |
| Renal impairment | GFR 15-30 mL/min: administer 50% of standard dose every 12 hours; GFR <15 mL/min: contraindicated (except during hemodialysis, where 50% dose post-dialysis may be used). |
| Liver impairment | Child-Pugh Class A/B: no adjustment necessary; Child-Pugh Class C: contraindicated due to risk of severe hepatotoxicity. |
| Pediatric use | Children >2 months: 8 mg/kg/day (based on trimethoprim) in two divided doses for UTI; for PCP prophylaxis: 150 mg/m²/day in two divided doses on 3 consecutive days per week. |
| Geriatric use | Increased risk of severe adverse reactions (e.g., hyperkalemia, renal impairment); monitor renal function and potassium levels; initiate at lower doses (e.g., half the standard dose) and titrate cautiously. |
| 1st trimester | Contraindicated: Risk of fetal nephrotoxicity and oligohydramnios. Also crosses placenta and may cause fetal renal impairment. |
| 2nd trimester | Contraindicated: Risk of fetal nephrotoxicity and oligohydramnios. Avoid use unless absolutely necessary. |
| 3rd trimester | Contraindicated: Risk of neonatal renal failure, oligohydramnios, and premature closure of ductus arteriosus. |
Clinical note
Comprehensive clinical and safety monograph for CO-LAV (CO-LAV).
| Placental transfer | Yes; active placental transport; achieves fetal concentrations comparable to maternal levels. |
| Breastfeeding | Excreted into breast milk in low amounts; however, potential for adverse effects in the infant (e.g., renal impairment, gastrointestinal effects). Use with caution, especially in preterm or jaundiced infants. |
| Lactation Rating | L3 (Moderately Safe) - limited data suggest low risk; monitor infant for diarrhea and rash. |
| Teratogenic Risk | First trimester: Not associated with major congenital malformations based on limited human data. Second and third trimesters: No specific fetal risks reported; however, placental transfer is minimal. |
| Fetal Monitoring | No specific fetal monitoring required. Maternal monitoring: Blood pressure, heart rate, and signs of bronchospasm during administration. |
| Fertility Effects | No adverse effects on human fertility reported. Animal studies show no impairment of fertility. |
■ FDA Black Box Warning
Codeine is contraindicated in children younger than 12 years and in children younger than 18 years following tonsillectomy and/or adenoidectomy due to risk of respiratory depression and death associated with ultra-rapid metabolism of codeine to morphine. Aspirin is associated with Reye's syndrome in children and adolescents with viral illnesses.
| Serious Effects |
Hypersensitivity to sulfonamides or sulfasalazineIntestinal or urinary obstructionPorphyria
| Precautions | Respiratory depression, risk of opioid addiction, abuse, and misuse; life-threatening respiratory depression in children with CYP2D6 ultra-rapid metabolizers; Reye's syndrome in children and adolescents with viral illnesses; increased risk of bleeding; gastrointestinal perforation and bleeding; renal impairment; hypersensitivity reactions including anaphylaxis and aspirin-sensitive asthma; drug interactions with CYP2D6 and CYP3A4 inhibitors/inducers; use in pregnancy and lactation. |
| Food/Dietary | Grapefruit juice may increase colchicine levels due to CYP3A4 inhibition; avoid concurrent consumption. High-fat meals may reduce colchicine absorption? No data for colchicine specifically; take with or without food. Alcohol may worsen gout symptoms and increase risk of pancreatitis; avoid. Lactulose effect is not dependent on food; can be taken with or without meals. |
| Clinical Pearls | CO-LAV (colchicine/lactulose) is a fixed-dose combination used for gout flare prophylaxis but poses risks in renal impairment; colchicine dose must be reduced in CKD stage 4-5 due to narrow therapeutic index. Lactulose may cause bloating and flatulence; monitor for diarrhea-related electrolyte disturbances. Avoid concurrent use with strong CYP3A4 inhibitors (e.g., clarithromycin, ketoconazole) and P-glycoprotein inhibitors (e.g., cyclosporine) to prevent colchicine toxicity. In liver impairment, colchicine accumulation can occur; use with caution. Geriatric patients are more susceptible to colchicine neurotoxicity and myopathy. |
| Patient Advice | Take this medication exactly as prescribed; do not exceed the recommended dose of colchicine. · If you have kidney or liver disease, inform your doctor; dose adjustments may be needed. · Report any signs of colchicine toxicity: muscle pain, weakness, numbness, tingling, or unusual bruising/bleeding. · Lactulose may cause gas, bloating, or stomach cramps; these usually improve over time. · Stay well hydrated to prevent diarrhea-related dehydration. · Do not take any other medications, including over-the-counter, without consulting your doctor. · If you are pregnant, planning to become pregnant, or breastfeeding, discuss risks with your healthcare provider. · Store at room temperature away from moisture and heat. |
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