Calcium Channel Blockers Co-prescribed with Loop Diuretics: A Potential Marker of Poor Prescribing?

Area of Science:

• Pharmacology
• Clinical Pharmacy
• Drug Safety

Background:

• Prescribing cascades involve treating drug side effects as new conditions, leading to polypharmacy.
• A common example is prescribing loop diuretics for peripheral edema caused by calcium channel blockers (CCBs).
• This practice is widespread despite CCBs lacking prognostic benefit in heart failure and increasing edema risk.

Purpose of the Study:

• To highlight the issue of prescribing cascades, specifically the CCB-loop diuretic combination.
• To advocate for medication reviews targeting patients on this combination.
• To emphasize the potential benefits of addressing this cascade for patient outcomes and healthcare costs.

Main Methods:

• Literature review and analysis of prescribing cascade mechanisms.
• Examination of the risks and benefits associated with CCBs and loop diuretics.
• Discussion of alternative management strategies for CCB-induced edema.

Main Results:

• Calcium channel blockers (CCBs) are associated with a significant risk of peripheral edema (8-18% absolute risk increase).
• CCBs offer no prognostic benefit in heart failure and may increase heart failure risk in hypertension treatment.
• Loop diuretics are often inappropriately prescribed to manage CCB-induced edema.

Conclusions:

• Switching to alternative medications is the preferred method for managing CCB-induced edema.
• The CCB-loop diuretic combination is rarely justified and often indicates a prescribing cascade.
• Targeting patients on CCB-loop diuretic combinations for medication review can improve quality of life and reduce polypharmacy, adverse drug reactions, and costs.