CARNITOR
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CARNITOR (CARNITOR).
Levocarnitine is a naturally occurring amino acid derivative involved in fatty acid oxidation. It acts as a carrier molecule for long-chain fatty acids across the inner mitochondrial membrane, facilitating their conversion into acetyl-CoA and subsequent energy production via beta-oxidation.
| Metabolism | Levocarnitine is not significantly metabolized in humans. It is primarily eliminated unchanged in urine via tubular reabsorption. Small amounts may be converted to trimethylamine (TMA) and trimethylamine N-oxide (TMAO) by gut microbiota. |
| Excretion | Renal (60-80% as carnitine and acylcarnitines); biliary/fecal minimal |
| Half-life | 17.4 hours (oral); 20-24 hours (IV) in steady state; prolonged in renal impairment |
| Protein binding | 0-1% (negligible); does not bind significantly to plasma proteins |
| Volume of Distribution | 0.2-0.3 L/kg (total body water); increased in deficiency states (up to 0.5 L/kg) |
| Bioavailability | 5-18% (oral) due to extensive first-pass metabolism; 100% (IV) |
| Onset of Action | IV: 30-60 minutes; oral: 2-6 hours |
| Duration of Action | 3-6 hours (IV); 6-8 hours (oral) for metabolic effects; sustained with chronic dosing |
| Action Class | Amino acids |
| Brand Substitutes | Carnikid Syrup, Carnisurge 500mg/5ml Syrup, Carnipil Syrup |
Primary carnitine deficiency: 990 mg orally twice daily (total 1980 mg/day). Hemodialysis-associated deficiency: 10-20 mg/kg intravenously as a slow 2-3 minute bolus after each dialysis session. Secondary carnitine deficiency: 50-100 mg/kg/day orally in divided doses, max 3 g/day.
| Dosage form | SOLUTION |
| Renal impairment | For oral dosing: No specific adjustment. For IV use in ESRD: Administer 10-20 mg/kg after each hemodialysis session; no reduction for milder impairment. In severe renal impairment (CrCl <30 mL/min), use with caution due to potential accumulation of metabolites. |
| Liver impairment | No specific Child-Pugh based adjustment; use standard dosing with monitoring for adverse effects in hepatic impairment. |
| Pediatric use | Primary carnitine deficiency: 50-100 mg/kg/day orally in divided doses, max 3 g/day. Hemodialysis: 10-20 mg/kg IV after dialysis. Metabolic disorders: 100-300 mg/kg/day orally in divided doses; max 3 g/day. |
| Geriatric use | No specific adjustments; use adult dosing with consideration of age-related renal decline. Monitor renal function and adjust dose if necessary based on GFR. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for CARNITOR (CARNITOR).
| Breastfeeding | Carnitine is a normal constituent of breast milk. Levels may increase with maternal supplementation. The M/P ratio is approximately 1:1. Carnitor is considered compatible with breastfeeding. Caution with large doses due to potential accumulation in infant. |
| Teratogenic Risk | Carnitine (CARNITOR) is not associated with major human teratogenicity. Animal studies show no evidence of fetal harm at doses up to 1.5 times the human dose. However, data in pregnant women are limited. Use during pregnancy only if clearly needed. No specific trimester risks identified. |
■ FDA Black Box Warning
None.
| Serious Effects |
["Hypersensitivity to levocarnitine or any component of the formulation"]
| Precautions | ["Seizures have been reported, especially in patients with pre-existing seizure disorders or on anticonvulsants","Use with caution in patients with end-stage renal disease, as metabolites may accumulate","Hemodialysis may remove carnitine; adjust dosage accordingly","Pregnancy category B: use only if clearly needed"] |
| Food/Dietary | Take with food to minimize gastrointestinal discomfort. No specific dietary restrictions, but avoid high-fat meals that may increase gastrointestinal side effects. Levocarnitine absorption may be reduced by high dietary pivalate (e.g., from pivalic acid esters). |
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| Fetal Monitoring |
| Monitor maternal serum free carnitine levels, especially in primary deficiency states. Assess fetal growth and wellbeing via ultrasound if underlying condition warrants. Monitor for signs of hypoglycemia in both mother and newborn. |
| Fertility Effects | No known adverse effects on fertility. Carnitine is involved in energy metabolism and may improve sperm motility in males with deficiency, but no significant impact on female fertility reported. |
| Clinical Pearls | Carnitor (levocarnitine) is used for primary and secondary carnitine deficiency. Monitor plasma carnitine levels periodically. In dialysis patients, administer 10-20 mg/kg IV after each dialysis session. May cause diarrhea at high oral doses; consider dose reduction if intolerable. |
| Patient Advice | Take Carnitor exactly as prescribed, typically with meals to reduce GI upset. · Report any new or worsening muscle weakness, nausea, vomiting, or diarrhea. · Do not stop taking Carnitor suddenly without consulting your doctor. · This medication is not a substitute for a healthy diet. · Store at room temperature away from moisture and heat. |