View Full Version : Antibiotic and Calcium-Channel Blocker a Fatal Combination

Sun 16th March '14, 11:36pm
From Medscape Week in Review at http://www.medscape.com/viewarticle/814306?src=wnl_edit_medn_wir&uac=180112PN&spon=34

ATLANTA — The antibiotic clarithromycin prescribed for patients already taking antihypertensive calcium-channel blockers is associated with increases in hospitalization for acute kidney injury, hypotension, and death, according to new research.

Coprescribing the 2 drugs is a common practice, despite warnings of serious interactions.

"Although the absolute risk increases were small, these outcomes have important clinical implications," said senior author Amit Garg, MD, from the London Health Sciences Centre and the University of Western Ontario.

"Our results suggest that potentially hundreds of hospitalizations and deaths in our region may have been associated with this largely preventable drug–drug interaction," he told Medscape Medical News. "This burden on the healthcare system, given the high cost of managing acute kidney injury, might have been avoided."

The results, presented here at Kidney Week 2013, were also published online November 9 in JAMA to coincide with their presentation.

Clarithromycin is an inhibitor of the cytochrome P453A4, the enzyme that metabolizes calcium-channel blockers. Previous research has shown that the antibiotic can send blood concentrations of calcium-channel blockers soaring by as much as 500%.