Article Text
Abstract
Aim The aim of the project was to establish whether patients with MCADD treated at Bristol Royal Hospital for Children (BRHC) are supplemented with l-carnitine and to establish further details for supplementation.
Background MCADD is the most common type of fatty acid oxidation disorder in the UK.1l-carnitine is a co-factor in the oxidation of fatty acids in mitochondria and eliminates excess medium chain fatty acids. l-carnitine supplementation in MCADD is controversial with no consistent findings in publications.2
Methods The paediatric metabolic database at BRHC was interrogated to find the number of patients with MCADD. Patients who were either deceased or discharged from the metabolic service were excluded. Medical notes and pharmacy records were reviewed for each patient to determine patient demographics, dosing information and reasons for implementation of l-carnitine using a data collection tool which was piloted on the first 5 patients. The data was analysed using Microsoft Excel.
Results Of 35 patients treated for MCADD, 13 patients (37%) received l-carnitine. The most common age group treated was 6–10 years (n=6). The mean dose of L-carnitine=77.7 mg/kg/day; range 45–100 mg/kg/day; most common dose=100 mg/kg/day (n=6). 92% of patients received the 300 mg/mL liquid. Of the 13 patients, 1 had low free carnitine but was asymptomatic; 8 were symptomatic with low levels and 3 were symptomatic with borderline low levels and 1 had no reason documented. All symptomatic patients improved with therapy. Those who stopped supplementation on correction (n=3), all restarted due to return of symptoms with falling levels. 2 of these patients have a vegetarian diet, a reason for low free carnitine. 2 patients had their doses reduced from 100 to 50 mg/kg/day due to side effects, particularly fishy body odour exacerbated by hot weather. 1 patient complained of the same effect, but the dose remained the same.
Conclusion The majority of patients in this centre are not treated with l-carnitine. The reason for treatment is mainly low free carnitine associated with symptoms. Clinical and biochemical improvement was observed with treatment. The most common dose prescribed was 100 mg/kg/day; with the observed side effect of a fishy body odour also being the most common reason for dose reduction. The most commonly prescribed preparation is a 300 mg/mL licensed liquid. Problems with availability and palatability reduce the usage of licensed tablet preparations. We hope to expand the project nationally with other UK metabolic centres.
References
Saudebray. Inborn metabolic diseases: Diagnosis and treatment (5th ed.) 2011. Springer.
Matern D, Rinaldo P. Medium-chain acyl-coenzyme a dehydrogenase deficiency 2015. GeneReviews®. 2000, updated 2015. http://www.ncbi.nlm.nih.gov/books/NBK1424/