Abstract Introduction Phentermine, an isomer of methamphetamine, is a sympathomimetic agent commonly prescribed for short-term weight loss. It primarily suppresses appetite by increasing norepinephrine release at the synaptic cleft. Although effective for weight loss, phentermine use has been associated with rare but significant cardiovascular and pulmonary complications, particularly in patients with pre-existing risk factors. Serious adverse events, including acute coronary syndrome, have been reported. This case underscores the importance of clinician awareness regarding the potential cardiovascular toxicity of phentermine, especially in individuals with comorbidities. Case Presentation A 58-year-old female with a past medical history of hypertension, diabetes mellitus, obesity (BMI 50.94), and anxiety presented with acute-onset left-sided weakness approximately one hour after ingesting a phentermine diet pill. On arrival, she was tachycardic and hypoxic, requiring intubation for airway protection and admission to the intensive care unit. Chest CT excluded pulmonary embolism but demonstrated diffuse bilateral posterior lung opacities, right greater than left, with air bronchograms consistent with bibasilar infiltrates. The pulmonary function ratio was 54, and the patient was initiated on dexamethasone for severe hypoxemia. Laboratory evaluation revealed leukocytosis and elevated troponins (peaking in the 4000s). EKG changes noted with T wave inversions and QTc prolongation. Echocardiogram obtained with ejection fraction 35 to 40% with hypokinesis in the setting of acute ischemic cardiomyopathy. Patient underwent high risk percutaneous intervention which showed multi-vessel disease and so a drug-eluting stent was placed to the LAD. The patient was discharged on dual anti-platelet therapy with aspirin and clopidogrel and optimized GDMT. Lifestyle modifications with diet and exercise were strongly recommended. Discussion This case highlights an uncommon life-threatening cardiovascular complication associated with phentermine use, particularly in patients with risk factors. The close relationship between phentermine ingestion and symptom onset in this patient, along with significant troponin elevation and EKG changes, strongly suggests a phentermine-induced acute myocardial infarction. The mechanism is likely multifactorial, involving coronary vasospasm, increased myocardial oxygen demand, and underlying atherosclerotic disease. This underscores the importance of physicians to recognize phentermine as a potential cause of acute cardiovascular compromise in high-risk patients and escalate care accordingly. This abstract is funded by: none
Mansuri et al. (Fri,) studied this question.