Background A 76-year-old man was admitted to a local rehabilitation inpatient facility following an acute myocardial infarction. Patient history included hypertension and previous stroke. The patient was being treated with clopidogrel and aspirin for secondary stroke prevention along with other medications to treat hypertension. The patient admitted to using cannabidiol (CBD) oil up to three times a day for knee pain prior to acute myocardial infarction and requested to continue its use in the facility. Assessment Prior to this hospital stay, the patient was able to continue activities of daily living with knee pain that was controlled by CBD oil used three times daily. The option to continue CBD oil would create a possible drug interaction with current cardiovascular medications leading to increased cardiovascular or bleeding risks. Outcome The patient was advised against the use of CBD products because of potential interaction with clopidogrel and was prescribed acetaminophen for osteoarthritis (knee pain). The patient continued to improve and was discharged to his home after two weeks of rehabilitation. Conclusion Based on limited pharmacodynamic and pharmacokinetic studies in older people, patients should avoid using cannabidiol and products containing its derivatives with P2Y12 inhibitors. A potential interaction between cannabidiol and its derivatives with P2Y12 inhibitors may increase a patient's cardiovascular or bleeding risks. Patients and health care providers must be adequately informed about potential risks associated with cannabidiol products and oral antiplatelets to prevent negative outcomes.