Isotretinoin Treatment for Acne Vulgaris: A Five-Year Retrospective Analysis of Clinical and Biochemical Adverse Effects.

Oral isotretinoin remains the most effective therapy for severe acne, but its exceptional efficacy is often accompanied by relatively frequent adverse effects. In this study, we quantified the frequency- and dose-related predictors of clinical and biochemical adverse effects during isotretinoin treatment in routine Polish practice. The records of 370 patients (mean age: 28 ± 12 years) who began isotretinoin treatment between June 2020 and June 2025 were reviewed. The mean daily isotretinoin and cumulative isotretinoin doses were 23.4 ± 9.1 mg and 88.3 ± 31.5 mg/kg, respectively. The adverse events documented at two-monthly visits were correlated with age and dosing. Lipid, hepatic, thyroid and prolactin panels were compared with age- and sex-matched controls using χ statistics and odds ratios (ORs). Xerosis (70%), retinoid dermatitis (20%) and cheilitis (15.5%) predominated. Hand eczema rose with higher daily isotretinoin doses (ρ = 0.082; = 0.037), whereas pruritus declined with greater cumulative isotretinoin exposure (ρ = -0.088; = 0.037). Retinoid dermatitis was linked to a younger age (ρ = -0.080; = 0.0286), whereas desquamation increased slightly with age (ρ = +0.083 = 0.0228). Overall, dyslipidemia was twice as common as in the controls (OR: 2.06; 95% CI: 1.49-2.86; -value: <0.0001), which was driven by an elevated total cholesterol (OR: 1.93; 95% CI: 1.34-2.77; -value: 0.0004), LDL (OR: 3.40; 95% CI: 2.26-5.10; -value: <0.0001) and triglycerides (OR: 1.95; 95% CI: 1.20-3.17; -value: 0.0062) and decreased HDL (OR: 2.68; 95% CI: 1.75-4.10; -value: <0.0001). Interestingly, hyperprolactinemia occurred eight-fold more often (OR: 8.42; 95%; 95% CI: 2.97-23.84; -value: <0.00001). Aminotransferase and TSH elevations were infrequent and statistically non-significant. At moderate cumulative doses, isotretinoin was generally well tolerated; however, clinically relevant lipid and prolactin disturbances were frequent. Routine lipid and endocrine monitoring, early emollient prophylaxis and dose individualization are recommended to ensure safe isotretinoin usage in everyday practice.