CARNITOR SF
Clinical safety rating: caution
Comprehensive clinical and safety monograph for CARNITOR SF (CARNITOR SF).
Carnitor SF (L-carnitine) is a primary endogenous carrier of long-chain fatty acids across the inner mitochondrial membrane for beta-oxidation and ATP generation; it also modulates acyl-CoA/CoA ratio and promotes elimination of toxic acyl groups.
| Metabolism | Not significantly metabolized; primarily excreted unchanged in urine as carnitine and acylcarnitines; renal reabsorption mediated by OCTN2 transporter. Small fraction undergoes minor conversion by gut microbiota (trimethylamine formation). |
| Excretion | Renal: 80-90% as unchanged drug; fecal: <5% |
| Half-life | Terminal elimination half-life: 17.4 hours (oral); clinical context: prolonged in renal impairment, dose adjustment needed for CrCl <30 mL/min |
| Protein binding | Low, <10%; primarily to albumin |
| Volume of Distribution | 0.4-0.6 L/kg; approximates total body water, indicating distribution into lean tissues |
| Bioavailability | Oral: 16-24% (variable, saturable absorption at high doses) |
| Onset of Action | Oral: 12-24 hours; IV: within minutes |
| Duration of Action | Oral: 8-12 hours; IV: dose-dependent, up to 24 hours; clinical notes: requires multiple daily dosing due to short duration |
1-3 g/day orally in divided doses (2-4 times daily) for metabolic disorders; for primary carnitine deficiency, 990 mg 2-3 times daily (max 3 g/day).
| Dosage form | SOLUTION |
| Renal impairment | For GFR <30 mL/min, reduce dose by 50% or increase dosing interval; monitor carnitine levels. Not recommended in ESRD unless on dialysis. |
| Liver impairment | No specific adjustment for Child-Pugh; caution in severe hepatic impairment. Monitor for adverse effects. |
| Pediatric use | 50-100 mg/kg/day orally in divided doses (max 3 g/day). For primary carnitine deficiency, 100-300 mg/kg/day. |
| Geriatric use | Start at lower end of dosing range (e.g., 500 mg twice daily); monitor renal function and adjust accordingly. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for CARNITOR SF (CARNITOR SF).
| Breastfeeding | Levocarnitine is endogenous in breast milk. Administration of CARNITOR SF may increase maternal and milk concentrations. M/P ratio not established. Caution is advised; consider developmental benefits of breastfeeding vs. potential for drug exposure. Monitor infant for adverse effects. |
| Teratogenic Risk | CARNITOR SF (levocarnitine) is a naturally occurring substance. No teratogenic effects have been reported in animal studies. In humans, limited data suggest no increased risk of major birth defects. However, adequate well-controlled studies in pregnant women are lacking. Use during pregnancy only if clearly needed. Risks by trimester: First trimester - no evidence of teratogenicity; Second and third trimesters - no fetal risks identified. |
■ FDA Black Box Warning
None
| Serious Effects |
["Known hypersensitivity to L-carnitine or any component of the formulation"]
| Precautions | ["Seizures: L-carnitine may cause or exacerbate seizures in patients with pre-existing seizure disorders.","Diarrhea: High doses may cause diarrhea; reduce dose if persistent.","Renal impairment: Adjust dose in hemodialysis patients; monitor plasma carnitine levels.","Hypersensitivity reactions: Discontinue if rash, urticaria, or anaphylaxis occurs.","Pregnancy: Safety not established; use only if clearly needed."] |
| Food/Dietary | High-fat meals may decrease absorption of oral levocarnitine; take with meals to improve tolerance. No specific food restrictions, but avoid excessive intake of foods rich in trimethylamine (e.g., fish, eggs, liver) as carnitine can be metabolized to trimethylamine, potentially causing a fishy odor. Carnitine is also found in red meat and dairy, but dietary sources do not significantly affect therapy. No interaction with caffeine or alcohol. |
Loading safety data…
| Fetal Monitoring | Monitor maternal carnitine levels and clinical response. In pregnancy, monitor for symptoms of overdose or deficiency. Fetal monitoring: standard prenatal care including ultrasound for growth and development if chronic use. No specific fetal monitoring required. |
| Fertility Effects | No known adverse effects on fertility in animal or human studies. Levocarnitine is essential for fatty acid metabolism and may support reproductive function. |
| Clinical Pearls | CARNITOR SF (levocarnitine) is a sugar-free formulation used for primary or secondary carnitine deficiency. In hemodialysis patients, administer 10-20 mg/kg IV bolus after each dialysis session to prevent deficiency. Monitor plasma free carnitine levels; therapeutic range 35-60 µmol/L. Use with caution in patients with seizure disorders as carnitine may lower seizure threshold. Avoid co-administration with pivalate-generating antibiotics (e.g., pivampicillin) as they increase carnitine excretion. In secondary deficiency due to valproic acid, dose reduction of valproate may be needed. |
| Patient Advice | Take levocarnitine exactly as prescribed, usually with or after meals to reduce gastrointestinal upset. · If you miss a dose, take it as soon as you remember; skip if almost time for next dose—do not double up. · Report symptoms of diarrhea, nausea, vomiting, or a fishy body odor (due to trimethylamine formation). · Maintain adequate fluid intake to prevent dehydration, especially if diarrhea occurs. · For hemodialysis patients: this medication is given after each dialysis session—do not take oral doses on non-dialysis days unless instructed. · Inform your doctor if you have a history of seizures or kidney impairment. · Avoid taking carnitine supplements without medical supervision. |