Ketamine-Induced Crystalline Gastritis

Abstract

Ketamine is an anesthetic agent commonly used for various pain syndromes. It is also a recreational drug. It is rarely prescribed orally because of its poor oral bioavailability. Oral dosages range from 0.5 mg/kg/day to 21 mg/kg/day based on the indication. A recent retrospective analysis reported gastropathy and gastritis in 80% of oral and inhalational ketamine users. A 27-year-old man with Mollaret's meningitis was admitted for intractable neuropathic pain; only parenteral ketamine provided symptomatic relief. He was later transitioned to oral ketamine, and prescribed up to 28 mg/kg/day for symptom control. One week later, he developed acute burning mid-epigastric pain and nausea. EGD revealed multiple “Band-Aid®”- like superficial plaques in the gastric cardia (Figure 1). Biopsy specimens showed active inflammation and deposits of clear refractile crystals in the gastric mucosa (Figure 2). Our clinical impression was ketamine-induced gastritis. Ketamine was discontinued and then reintroduced at 4 mg/kg/day. The patient's epigastric symptoms resolved. Three weeks later, a repeat EGD confirmed mucosal healing and absence of plaque. Biopsy specimens revealed inactive gastritis without crystalline deposition.Figure 1Figure 2This report is the first description in the literature of a crystalline-associated reactive gastritis in a patient on oral ketamine. The clinical features that support causality with ketamine include abrupt symptom onset with initiation of ketamine, lack of clinical or endoscopic features to suggest an alternative diagnosis, and prompt histologic and clinical resolution with cessation of ketamine. We speculate that crystalline-associated reactive gastritis is a dose-dependent phenomenon, as our patient was on a higher total dosage of oral ketamine than described in the literature. There were no excipients in the ketamine capsules that may have crystallized in vivo, suggesting ketamine crystallization was responsible for the patient's reactive gastritis. To investigate this hypothesis, we suspended a 5% solution of ketamine in normal saline. The specimen was examined under white light and polarizing light microscopy. Clear refractile crystals (Figure 3), similar to our patient's gastric biopsy specimen, were noted.Figure 3Our analysis strongly supports a case of ketamine-induced crystalline gastritis. Practitioners should be aware of this previously undescribed complication of oral ketamine.