Abstract
In this case series, we discuss 10 cases of norethindrone-induced transaminitis and conduct a literature review of this rare adverse event. A retrospective chart review was conducted on 10 patients (median age: 33 years) with diverse endometriosis phenotypes who received norethindrone and subsequently developed transaminitis, which is defined as elevated alanine transaminase (ALT) and aspartate transaminase (AST) levels. This condition was diagnosed in both asymptomatic and symptomatic patients, either during the work-up of acute symptoms or incidentally through routine lab tests. Our objective was to assess and characterize a case series of transaminitis associated with norethindrone use in endometriosis patients, detailing clinical presentations, management strategies, and outcomes. All cases exhibited normalization of liver function tests after discontinuation, occurring within one to 12 months with varying intervals of liver function testing. Patients receiving higher dosages (10 mg daily) demonstrated quicker resolution (average: four months). The reported adverse effects included nausea, vomiting, headache, rash, polyarthralgia, and abnormal uterine bleeding. Vigilant management, including prompt discontinuation, consistently resulted in the resolution of transaminitis. This study underscores the importance of continuous monitoring of liver function, even in asymptomatic patients on norethindrone therapy. Further investigations are imperative to identify specific groups susceptible to this adverse event.