O07 To test or not to test? Isotretinoin blood test monitoring in children and adolescents in a teaching hospital over 2 years.

Abstract

Current recommendation for blood test monitoring for isotretinoin is liver function tests and fasting lipids for all patients at baseline, 1 month after treatment and every 3 months. However, a recent critical appraisal of the evidence indicates that serious adverse events are rare and often not reliably preventable through routine monitoring. We conducted a retrospective review of all blood tests performed for isotretinoin monitoring in paediatric and adolescent patients between June 2021 and June 2023 in a single teaching hospital. Two-thousand six-hundred and eighty-two blood tests from 165 patients were recorded: Liver function:707 tests; 9 results from 3 patients showed ALT > 160 U/L, all linked to preexisting liver abnormalities/comorbidities.Lipids:557 tests;12 results from 10 patients showed triglycerides >3.0 mmol/L; all were attributed to non-fasting samples; all normalized during treatment. No pancreatitis was reported. Full Blood Count: 725 tests; No clinically significant thrombocytopenia (<100 × 109/L) or neutropenia (<1.0 × 109/L) was observed. No drug-induced agranulocytosis was detected. Renal function: 693 tests; 5 significant abnormal creatinine results were found (>100 µmol/L) belonging to 3 patients, all linked to baseline derangements. The necessity for routine blood tests for isotretinoin in otherwise healthy children and adolescents should be challenged due to the rarity of severe side effects and lack of evidence of preventable adverse outcomes. A more tailored, risk-based monitoring approach should be considered to optimise resource utilization and improve patient experience without compromising safety. Patients should be educated on clinical signs of rare but relevant adverse complications such as pancreatitis and rhabdomyolysis.