Impact of Isotretinoin Therapy on Thyroid Hormone Levels in Patients with Acne Vulgaris

INTRODUCTIONSystemic isotretinoin is extensively used to treat moderate-to-severe acne vulgaris and may have systemic endocrine effects through the hypothalamic-pituitary-thyroid axis.

OBJECTIVESTo investigate the changes in thyroid hormone levels after commencement of systemic isotretinoin among patients with acne vulgaris.

METHODSA PubMed, ScienceDirect, Scopus, and Cochrane Library search was performed. Pooled analysis was conducted utilizing Review Manager (RevMan 5.4.1).

RESULTSA total of 447 patients from eight observational studies were included. After three and four months, no increase in TSH levels was observed following isotretinoin treatment with a standardized mean difference (SMD) of 0.09 (95% CI: -0.27-0.46; P=0.62) and (SMD=0.72; 95% CI: -0.01-1.45; P>0.05), respectively. However, a significant increase in TSH levels was observed at six months (SMD=0.54; 95% CI: 0.05-1.03; P=0.03). T4 levels showed no alteration at three months (SMD= -0.24; 95% CI: -0.56-0.08; P=0.14) but were reduced at four months (SMD= -0.79; 95% CI: -1.20--0.38; P=0.0001) and six months (SMD= -0.87; 95% CI: -1.57--0.17; P=0.01). T3 levels were reduced at three months (SMD= -0.42; 95% CI: -0.80--0.04; P=0.03), four months (SMD=-0.63; 95% CI: -1.03--0.23; P=0.002), and 6 months (SMD= -1.13; 95% CI: -1.77--0.55; P=0.0001).

CONCLUSIONLong-term isotretinoin treatment may cause time-dependent changes in thyroid hormone levels.

Abstract from PubMed