Severe lactose intolerance in a patient with coronary artery disease and ischemic cardiomyopathy

A 72-year-old man with severe lactose intolerance was admitted for non-ST-segment elevation myocardial infarction. The coronary angiogram revealed occlusion of the distal third of the first diagonal artery and several non-significant lesions. The pre-discharge echocardiogram revealed moderate left ventricular systolic dysfunction. Discharged on dual antiplatelet therapy, rosuvastatin, perindopril and carvedilol, he was repeatedly readmitted in the following days for abdominal pain/bloating, diarrhea and nausea despite avoiding food products containing lactose. To date, there has been no comprehensive study on the relationship between lactose intolerance and coronary disease, nor has its impact on therapeutics been appropriately addressed. Intolerance to lactose-containing prescription medicines is an extremely rare phenomenon and few strategies are available to overcome this condition, as it has received little attention from the scientific community. Commercial forms of the lactase enzyme and probiotics can limit symptom severity, but different routes of administration, different brands of the same medicine or completely different medicines may be necessary. Some measures were proposed to our patient and, soon afterwards, he was completely asymptomatic in both gastrointestinal and cardiovascular terms.