Acute Changes in Liver Function Tests During Initiation of Ketogenic Diet

Background Ketogenic diet is an effective therapy for patients with medically refractory epilepsy. It is generally well tolerated, with the most common side effects being gastrointestinal. Hepatic toxicity has been described as an uncommon side effect of ketogenic diet, usually with long-term use. However, there are limited data to implicate ketogenic diet in acute liver toxicity.Methods and results We analyzed all patients who underwent elective inpatient ketogenic diet initiation at our institution from June 2019 to June 2022. Of the 25 patients reviewed, we found 6 patients who showed acute, asymptomatic changes in liver function tests during initiation, in both hepatocellular and cholestatic patterns. Two patients stopped the ketogenic diet acutely and 3 patients continued ketogenic diet with changes in medications and/or addition of choline-all patients had improvement and normalization of liver function tests in the short term. One patient had acute normalization of chronically elevated liver function tests on ketogenic diet initiation.Conclusion Ketogenic diet can cause acute changes in liver function tests during initiation of ketogenic diet, with both hepatocellular and cholestatic patterns, with and without the concurrent use of hepatotoxic medications. In most patients, ketogenic diet can be continued successfully by making changes to medications or addition of choline.