Challenges in diagnosing a metabolic disorder: error of pyruvate metabolism or drug induced?

Abstract

Certain drugs are known to cause metabolic changes resulting in altered metabolic profiles. We report here a case where a combination of antiepileptic drugs resulted in a profile that mimicked a metabolic disorder. A 16month-old female child on antiepileptic drugs (valproate and topiramate) was suspected to have the inherited metabolic disorder, dihydrolipoamide dehydrogenase deficiency, based on clinical symptoms and metabolic profile showing hyperalaninemia, elevated branched-chain amino acids, and lactate-pyruvate ratio. Suspecting that the observed metabolic changes could have also arised from medication, current medication was weaned off and replaced with levetiracetam, clonazepam, and levocarnitine (supportive therapy). Metabolic profiling conducted after 47 days showed normal alanine, branched-chain amino acids, ornithine, and lactate-pyruvate ratio, suggesting that the earlier abnormalities could have been medication induced. We stress that metabolic changes resulting from chronic medication should be considered while interpreting a positive result when investigating an inherited metabolic disorder.

• Authors: George Tomy Mampilly, Tomy Kochuvareed Mampilly, Rita Christopher, Neeradha Chandramohan, Vijayalakshmy Janaki
• Journal: Journal of child neurology (J Child Neurol) Vol. 29 Issue 6 Pg. 833-6 (Jun 2014) ISSN: 1708-8283 [Electronic] United States
• PMID: 23439713 (Publication Type: Case Reports, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © The Author(s) 2013.

Chemical References

• Anticonvulsants
• Topiramate
• Fructose
• Valproic Acid
• Pyruvic Acid

Topics

• Anticonvulsants (adverse effects)
• Female
• Fructose (adverse effects, analogs & derivatives)
• Humans
• Infant
• Metabolic Diseases (chemically induced, diagnosis)
• Pyruvic Acid (metabolism)
• Topiramate
• Valproic Acid (adverse effects)