Is amlodipine (calcium channel blocker) associated with causing cough as a side effect?

Amlodipine Does Not Cause Cough as a Side Effect

Amlodipine, a calcium channel blocker, does not cause cough as a side effect and can actually be used as an alternative treatment for patients who experience ACE inhibitor-induced cough. 1, 2

Understanding ACE Inhibitor-Induced Cough vs. Calcium Channel Blockers

• ACE inhibitor-induced cough is a well-documented side effect occurring in 5-35% of patients taking ACE inhibitors, caused by the accumulation of bradykinin and substance P when ACE is inhibited 1, 3
• The cough associated with ACE inhibitors is typically dry, persistent, and often begins within days to weeks after starting the medication 2
• Calcium channel blockers like amlodipine work through a completely different mechanism - inhibiting calcium influx through "slow" channels in vascular smooth muscle cells - and do not affect bradykinin metabolism 4
• Amlodipine has been shown to attenuate cough due to ACE inhibitors in randomized, double-blind, placebo-controlled trials 1

Clinical Evidence Supporting Amlodipine for Patients with Cough

• The American College of Chest Physicians guidelines specifically mention calcium channel antagonists including amlodipine as agents demonstrating the ability to attenuate cough due to ACE inhibitors 1
• In patients for whom ACE inhibitor therapy cannot be discontinued, amlodipine is recommended as a pharmacologic therapy aimed at suppressing cough 1
• Clinical case reports document successful resolution of cough when switching from ACE inhibitors to calcium channel blockers like amlodipine 5

Treatment Algorithm for Patients with ACE Inhibitor-Induced Cough

1. First-line approach: Discontinue the ACE inhibitor as this is the only uniformly effective treatment 1, 2
2. If antihypertensive therapy is still needed, consider these alternatives:
   • Angiotensin receptor blockers (ARBs) are the preferred alternative as they have a similar mechanism of action to ACE inhibitors but don't affect bradykinin metabolism 3, 2
   • Calcium channel blockers like amlodipine are excellent alternatives, particularly for patients over 55 years old 2, 4
   • Thiazide-like diuretics can also be considered if CCBs are not suitable 2

Important Clinical Considerations

• When switching from an ACE inhibitor to amlodipine due to cough, monitor blood pressure closely to ensure adequate control 2
• Amlodipine is well-tolerated and does not cause some of the undesirable effects often associated with other cardiovascular agents (e.g., adverse changes in serum lipid patterns, cardiac conduction disturbances) 4
• The most common adverse effects of amlodipine are edema and flushing, which are related to its vasodilatory action and are generally mild to moderate in severity 4

Rare Exceptions

• While extremely rare, there have been isolated case reports of cough associated with ARBs (like losartan), which resolved after switching to an ACE inhibitor 6
• These exceptions are very uncommon and do not change the general recommendation that calcium channel blockers like amlodipine do not cause cough 2, 4