Heparin-induced hyperkalemia.

We have described three patients with diabetes and renal insufficiency who had hyperkalemia during heparin therapy. These cases lend support to previous findings, and emphasize the clinical importance of this entity. We believe that heparin-induced hyperkalemia is a potentially life-threatening problem that is more common than previously appreciated. We suggest that in high-risk patients (ie, those with diabetes and/or renal insufficiency) serum potassium be monitored frequently during heparin therapy.