Pancreatitis and severe metabolic abnormalities due to phenformin therapy
G. M. Graeber, B. M. Marmor, R. C. Hendel and R. O. Gregg
Two elderly diabetic patients with abdominal pain were demonstrated to have
complications of phenformin hydrochloride therapy. The first developed
severe lactic acidosis treated with sodium bicarbonate given intravenously
and followed by rebound alkalosis. The second showed severe acidosis
(specimens for lactate determination were unfortunately unsatisfactory for
analysis) and similar alkalotic rebound after therapy. She then developed
severe pancreatitis, proved at operation, no cause for which other than
phenformin was apparent. Poor renal and hepatic function predispose to
these conditions by increasing serum phenformin levels and by decreasing
urinary excretion of its metabolites. The acidosis should be treated
judiciously with sodium bicarbonate administered intravenously. A rebound
alkalosis, ensuring as the accumulated lactate is metabolized, is best
treated by potassium chloride and ammonium chloride given intravenously.
The mechanism by which phenformin causes pancreatitis is unknown, but
termination of therapy causes cessation of the pancreatitis.
