From the Guidelines
Amlodipine as an AV Nodal Blocking Agent
Amlodipine is not an atrioventricular (AV) nodal blocking agent.
- The evidence consistently shows that amlodipine, a dihydropyridine calcium channel blocker, has few or no AV or sinus node effects 1.
- In contrast, verapamil and diltiazem, which are non-dihydropyridine calcium channel blockers, have prominent AV and sinus node effects 1.
- Amlodipine's primary action is as a peripheral arterial dilator, which reduces blood pressure and decreases myocardial oxygen demand 1.
- The guidelines and studies suggest that amlodipine can be used to control ongoing or recurring ischemia-related symptoms in patients with unstable angina/non-ST-elevation myocardial infarction (UA/NSTEMI), but its use is not primarily as an AV nodal blocking agent 1.
From the FDA Drug Label
Amlodipine does not change sinoatrial nodal function or atrioventricular conduction in intact animals or man. In patients with chronic stable angina, intravenous administration of 10 mg did not significantly alter A-H and H-V conduction and sinus node recovery time after pacing. In clinical trials with angina patients alone, amlodipine therapy did not alter electrocardiographic intervals or produce higher degrees of AV blocks
Amlodipine is not an atrioventricular (AV) nodal blocking agent, as it does not affect AV conduction or produce AV blocks 2.
From the Research
Amlodipine's Effect on Atrioventricular (AV) Nodal Conduction
- Amlodipine is a calcium channel blocker that has been studied for its effects on AV nodal conduction 3, 4.
- One study found that amlodipine slightly prolonged AV nodal conduction, as reflected by increases in atrial-His bundle and AV conduction times and PR interval, 30 minutes after administration 3.
- However, another study found that amlodipine has no effect on sinus or atrioventricular node and little or no effect on the resting heart rate 4.
- Amlodipine's effects on AV nodal conduction are similar to those of diltiazem or verapamil, but it does not have the same level of negative inotropic effect as these drugs 3, 5.
Comparison with Other Calcium Channel Blockers
- Amlodipine is a dihydropyridine calcium antagonist with a long half-life, which allows for once-daily dosing 4, 6.
- Unlike other dihydropyridines, such as nifedipine, amlodipine has a more gradual onset of effect and does not cause significant changes in heart rate or AV nodal conduction 5, 4.
- Amlodipine's pharmacodynamic profile is consistent with its disposition, with a gradual decrease in blood pressure over 4-8 hours and a slow return to baseline over 24-72 hours 6.
Clinical Implications
- Amlodipine is effective for the treatment of hypertension and angina pectoris, with a low risk of adverse effects on AV nodal conduction 4, 7.
- Its long half-life and gradual onset of effect make it a suitable choice for once-daily dosing, with minimal fluctuation in plasma drug concentration and blood pressure over the 24-hour dose interval 6, 7.