Select the adverse effects of dihydropyridine calcium‑channel blockers (e.g., amlodipine, nifedipine, felodipine): peripheral edema, facial flushing, bradycardia, angioedema, or dry cough.

Adverse Effects of Dihydropyridines

The correct adverse effects of dihydropyridine calcium channel blockers are peripheral edema (a) and facial flushing (b), while bradycardia (c), angioedema (d), and dry cough (e) are not characteristic adverse effects of this drug class. 1, 2

Confirmed Adverse Effects

Peripheral Edema (Option a - CORRECT)

• Peripheral edema is the most common adverse effect of dihydropyridines, occurring in 10.7% of patients compared to 3.2% with placebo 3
• The FDA label for amlodipine reports dose-dependent edema rates: 1.8% at 2.5mg, 3.0% at 5mg, and 10.8% at 10mg, compared to 0.6% with placebo 2
• This edema results from preferential dilation of pre-capillary arterioles, increasing capillary hydrostatic pressure without causing true fluid retention or volume overload 4
• Women experience significantly higher rates than men (14.6% vs 5.6% for amlodipine) 2
• The incidence increases with duration of therapy, reaching 24% after 6 months 3

Facial Flushing (Option b - CORRECT)

• Flushing is a well-documented vasodilatory adverse effect of dihydropyridines 1, 2
• The FDA label reports flushing in 2.6% of patients on amlodipine 10mg versus 0% with placebo 2
• Women experience higher rates than men (4.5% vs 1.5%) 2
• This effect is particularly common with short-acting dihydropyridines due to reflex sympathetic activation 1

Incorrect Options

Bradycardia (Option c - INCORRECT)

• Dihydropyridines do NOT cause bradycardia; in fact, reflex tachycardia is more common, especially with short-acting formulations 1
• Dihydropyridines have high selectivity for vascular L-type calcium channels and minimal effects on cardiac pacemaker and AV conduction cells 1
• Bradycardia is characteristic of non-dihydropyridine calcium channel blockers (diltiazem and verapamil), not dihydropyridines 1

Angioedema (Option d - INCORRECT)

• While the FDA label mentions angioedema as occurring in <1% of patients, this is extremely rare and not a characteristic adverse effect of dihydropyridines 2
• Angioedema is far more commonly associated with ACE inhibitors, not calcium channel blockers 5

Dry Cough (Option e - INCORRECT)

• Dry cough is NOT an adverse effect of dihydropyridine calcium channel blockers 5
• Dry cough is a characteristic adverse effect of ACE inhibitors, occurring due to bradykinin accumulation 5
• This is an important distinguishing feature when selecting antihypertensive agents 5

Additional Common Adverse Effects Not Listed

• Headache, dizziness, palpitations, and systemic hypotension are other vasodilatory effects commonly seen with dihydropyridines 1, 2
• All these effects are related to the peripheral vasodilatory action of the drug class 6