Abstract

Anticoagulants are among the most commonly prescribed medications worldwide. With the legalization of marijuana across an increasing number of states, cannabis use has steadily increased nationwide in North America. There are limited studies on effects of natural cannabis on commonly prescribed anticoagulants such as vitamin K antagonists. The following case serves to educate on this potential interaction and encourage future studies given the prevalence of warfarin and marijuana and possible concomitant use in the United States. We present a case of a 53-year-old male on a stable dose of warfarin who presented to the emergency department with one week of progressively worsening lower abdominal and back pain, constipation and hematuria. He had a past medical history of stroke, interatrial septal aneurysm with patent foramen ovale. He began experiencing these acute gastrointestinal and urological symptoms soon after getting a prostate MRI to workup an elevated PSA level.