A42-12 Drug-induced Pulmonary Arterial Hypertension From Over-the-counter Diet Pills and Methamphetamine Use

Abstract Introduction Drug-induced pulmonary arterial hypertension (PAH) remains a clinically important but underrecognized entity. Appetite suppressants and amphetamine derivatives are known to trigger pulmonary vascular remodeling through serotonergic and mitogenic mechanisms. Despite increased awareness, both prescription and illicit stimulant use continue to contribute to PAH cases. This report describes severe PAH likely caused by chronic diet pill use, acutely exacerbated by methamphetamine exposure. Case Description A 53-year-old woman with hypertension and obstructive sleep apnea underwent elective right heart catheterization for evaluation of progressive exertional dyspnea and peripheral edema (Figure 1A). Transthoracic echocardiography demonstrated preserved left ventricular ejection fraction (65-70%) and markedly elevated (107 mmHg) right ventricular systolic pressure (RVSP; Figure 1B). Catheterization confirmed severe precapillary pulmonary hypertension with mean pulmonary artery pressure 60 mmHg, pulmonary capillary wedge pressure 15 mmHg, cardiac output 5.7 L/min, and pulmonary vascular resistance 8 Wood units. Upon further questioning, she reported intranasal methamphetamine use and prior chronic use of over-the-counter diet pills. Workup excluded secondary causes of PAH, including autoimmune, infectious, and thromboembolic disease. She was diagnosed with World Health Organization (WHO) Group 1 PAH, likely secondary to stimulant and appetite suppressant exposure. Triple therapy with treprostinil, tadalafil, and macitentan was initiated, later transitioned to oral selexipag. Her oxygen requirement decreased, and repeat echocardiography showed improvement in RVSP to approximately 40 mmHg at discharge. Discussion This case illustrates the continuing relevance of drug-induced PAH in the modern era. Stimulant-associated PAH results from serotonin-mediated proliferation of pulmonary arterial smooth muscle, causing fixed vascular remodeling and right ventricular strain. Although early recognition and guideline-directed triple therapy can improve outcomes, advanced cases remain progressive despite treatment. Clinicians must maintain a high index of suspicion and obtain detailed substance use histories, including non-prescription weight loss agents and illicit stimulants. Education on the cardiovascular risks of amphetamine and diet pill exposure remains essential for prevention. This case reinforces the importance of comprehensive risk factor screening in all patients presenting with unexplained PAH. This abstract is funded by: None