Amitriptyline Induced Thrombocytopenia and Subconjunctival Haemorrhage

Abstract

Subconjunctival haemorrhage is typically a harmless, self-resolving condition, usually caused by ocular trauma. Its prevalence has risen with increased rates of systemic hypertension, diabetes, hyperlipidaemia, and the use of anticoagulants. Amitriptyline, a widely used tricyclic antidepressant, is commonly prescribed for major depressive disorder and some off-label conditions. The case aims to examine amitriptyline induced thrombocytopenia and subconjunctival haemorrhage. Although it generally has a favourable safety profile, there are case reports and studies linking amitriptyline with platelet dysfunction. Research suggests that bleeding events related to this drug are more likely in individuals who are vulnerable due to platelet dysfunction, inhibition of platelet monoamine oxidase (MAO), or, in rare cases, an idiosyncratic reaction. One case of thrombocytopenia accompanied by subconjunctival haemorrhage occurred in a patient taking amitriptyline at a dose of 25 mg/day, which resolved after discontinuing the drug. This rare side effect underscores the need for caution when using amitriptyline in certain patients. Evidence suggests that such bleeding episodes and thrombocytopenia occur in vulnerable individuals due to various direct and indirect mechanisms. It is vital to understand these mechanisms for the proper management of patients treated with amitriptyline.