Backround: Despite extensive usage of systemic isotretinoin in patients with acne for many years, laboratory monitoring protocols for adverse effects depend on the centers and there is no standardized practice for frequency and type of laboratory testing. We aimed to decrease unnecessary monitoring and to standardize our general clinical practice of our department as well as to provide patient comfort and cost saving. Materials and methods: The medical charts of 704 acne patients treated with systemic isotretinoin were reviewed retrospectively. The National Cancer Institute common terminology criteria for adverse events v3.0 grading system was used in order to categorize the laboratory abnormalities of liver functions and lipid levels. Results: All laboratory abnormalities were grade I. Abnormal liver function was seen in 7.2% of the patients (n = 51), maximum values were ALT: 87 IU/L, AST: 97 IU/L (normal values, ALT: 5-41 IU/L, AST: 5-40 IU/L) and median time of the abnormalities in liver function tests was in the second month. Lipid profile abnormalities were detected in 58% of the patients (n = 401). Maximum values during the laboratory monitoring were Tg: 481 mg/dL CHOL: 314 mg/dL, LDL: 259 mg/dL (normal values, Tg: 0-200 mg/dL, CHOL.: 0-200 mg/dL, LDL: 0-100 mg/dL). The median time of lipid abnormalities was in the first month (1-3 months). Abnormalities related to CBC were seen in 8.2% of the patients (n = 58). The median time of CBC abnormality was the second month of treatment. Anemia, leukopenia and thrombocytopenia were seen in 3.4%, 3.7%, and 1.6% of the patients respectively. Conclusion: Clinically insignificant and reversible CBC abnormalities, mild to moderate elevation of liver transaminases and serum lipids are the most common laboratory abnormalities in patients with acne treated with oral isotretinoin. Due to these abnormalities are reversible even the isotretinoin therapy continued, and generally there is no need to discontinuation of treatment due to laboratory abnormalities, frequent biochemical monitoring is not recommended.
Keywords: Acne vulgaris; laboratory monitoring; systemic isotretinoin.