Carnitine-related hypoglycemia caused by 3 days of pivalate antibiotic therapy in a patient with severe muscular dystrophy: a case report.

ABSTRACT

BACKGROUND: Long-term treatment with antibiotics containing pivalic acid may decrease serum carnitine concentration and can sometimes be associated with severe hypoglycemia and encephalopathy in infants. Little has been reported, however, on severe hypocarnitinemia induced by acute administration in older children. CASE PRESENTATION We describe a 6-year-old Japanese girl with Fukuyama-type congenital muscular dystrophy who lost consciousness after 3 days of treatment with an antibiotic containing pivalic acid (cefditoren pivoxil). Investigations at the onset of unconsciousness revealed hypoglycemia (free plasma glucose concentration 31 mg/dL) and hypocarnitinemia (serum free carnitine concentration 6.2 µmol/L). Intravenous administration of glucose rapidly improved her symptoms without any complications. Serum free carnitine concentration was 29.0 µmol/L immediately prior to the initiation of cefditoren pivoxil. Computed tomography scanning showed severe peripheral skeletal muscle atrophy, indicating the likelihood of decreased carnitine stores in skeletal muscle. CONCLUSIONS: Although serum carnitine concentration can appear deceptively normal, skeletal muscle carnitine stores can be reduced in patients with severe muscular atrophy. Even a short course of a pivalate-containing antibiotic can lead to life-threatening hypocarnitinemia in older children with severe muscular dystrophy.