L-carnitine supplementation in patients with cystic acne on isotretinoin therapy

J Eur Acad Dermatol Venereol. 1999 Nov;13(3):205-9.


Background: Patients with cystic acne (CA) on Isotretinoin (Iso) therapy might present muscular symptoms as side effect of the drug. Myalgia, weakness, hypotension are also some of the main characteristics of carnitine (car) deficiency.

Methods: Two hundred and thirty (N = 230) patients with CA were treated with Isotretinoin (0.5 mg/kg per 24 h). All the patients were requested to visit our out-patient department at the onset of muscular symptoms. Laboratory tests including car (total, free, acylcarnitine) were determined in blood and urine before treatment, at the onset of muscular symptoms and after the end of a 45 day study. Fifty percent of the patients with muscular involvement received L-carnitine (100 mg/kg per 24 h per os) (group C) and 50% placebo (group P).

Results: Their laboratory tests showed the well known increases of their liver enzymes and lipids, whereas car blood levels were remarkably decreased at the onset of their muscular symptoms and or at the end of the study. Their supplementation with L-car, in patients of group C (N = 20) without Iso discontinuation or reduction, resulted in the disappearance of their muscular symptoms within 5-6 days and normalisation not only of the increased levels of their liver enzymes but also those of car, at the 45 day of their therapy. Additionally, the patients who received placebo (group P, N = 20) continued complaining for mualgias. The rest of the patients (group A, N = 190) did not experience any muscular symptoms, their laboratory tests showed elevation of liver enzymes and lipids and a decrease in car levels in the blood whereas a remarkable increase of car excretion was determined in their urine.

Conclusions: Iso therapy decreases car blood levels in patients with CA. L-car supplementation might treat liver and muscular side effects of the drug. These hopeful preliminary results need further investigation.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Acne Vulgaris / drug therapy*
  • Adult
  • Alanine Transaminase / blood
  • Alkaline Phosphatase / blood
  • Aspartate Aminotransferases / blood
  • Carnitine / analogs & derivatives
  • Carnitine / blood
  • Carnitine / deficiency
  • Carnitine / therapeutic use*
  • Carnitine / urine
  • Case-Control Studies
  • Cholesterol / blood
  • Female
  • Follow-Up Studies
  • Humans
  • Isotretinoin / adverse effects*
  • Keratolytic Agents / adverse effects*
  • Liver / enzymology
  • Male
  • Muscle Weakness / chemically induced
  • Muscle Weakness / drug therapy
  • Muscular Diseases / chemically induced
  • Muscular Diseases / drug therapy*
  • Pain / chemically induced
  • Pain / drug therapy
  • Placebos
  • Triglycerides / blood


  • Keratolytic Agents
  • Placebos
  • Triglycerides
  • acylcarnitine
  • Cholesterol
  • Aspartate Aminotransferases
  • Alanine Transaminase
  • Alkaline Phosphatase
  • Isotretinoin
  • Carnitine