What are the side effects of amlodipine?

Side Effects of Amlodipine

The most common side effects of amlodipine are peripheral edema (swelling of legs/ankles), headache, dizziness, flushing, and fatigue, with edema being dose-dependent and occurring in up to 10.8% of patients at the 10 mg dose 1.

Common Side Effects (Dose-Related)

The FDA drug label clearly documents that certain side effects increase with higher doses 1:

• Peripheral edema: 1.8% at 2.5 mg, 3.0% at 5 mg, and 10.8% at 10 mg (compared to 0.6% with placebo)
• Dizziness: 1.1% at 2.5 mg, 3.4% at 5 mg and 10 mg (vs 1.5% placebo)
• Flushing: 0.7% at 2.5 mg, 1.4% at 5 mg, 2.6% at 10 mg (vs 0% placebo)
• Palpitations: 0.7% at 2.5 mg, 1.4% at 5 mg, 4.5% at 10 mg (vs 0.6% placebo)

Other Common Side Effects (>1% incidence)

1:

• Fatigue: 4.5% (vs 2.8% placebo)
• Nausea: 2.9% (vs 1.9% placebo)
• Abdominal pain: 1.6% (vs 0.3% placebo)
• Somnolence: 1.4% (vs 0.6% placebo)

Gender Differences

Women experience significantly higher rates of certain side effects compared to men 1:

• Edema: 14.6% in women vs 5.6% in men
• Flushing: 4.5% in women vs 1.5% in men
• Palpitations: 3.3% in women vs 1.4% in men

Cardiovascular Side Effects

Less common (<1% but >0.1%) cardiovascular effects include 1:

• Arrhythmias (including ventricular tachycardia and atrial fibrillation)
• Bradycardia
• Chest pain
• Syncope
• Tachycardia
• Vasculitis

Other Notable Side Effects

1:

• Gastrointestinal: Constipation, gingival hyperplasia, pancreatitis (rare)
• Dermatologic: Angioedema, erythema multiforme, pruritus, rash
• Musculoskeletal: Muscle cramps, myalgia, arthralgia
• Neurologic: Paresthesia, tremor, peripheral neuropathy
• Psychiatric: Sexual dysfunction, insomnia, nervousness, depression
• Hematologic: Leukopenia, purpura, thrombocytopenia (rare)
• Metabolic: Hyperglycemia

Pediatric Considerations

In children, amlodipine-related edema appears less common than in adults, but generalized edema can occur and requires monitoring 2, 3. Pediatric guidelines list common adverse effects as flushing, peripheral edema, and dizziness 2, 4.

Severe/Life-Threatening Effects

2, 5:

• Angioedema (rare but serious)
• Severe hypotension (especially in overdose)
• Bradycardia and cardiac depression (particularly in overdose or with concomitant beta-blockers)

Management of Edema

Peripheral edema from amlodipine does not respond to diuretics 6. Management options include:

1. Reduce dosage (edema is significantly less frequent at lower doses)
2. Switch to lercanidipine or lacidipine
3. Add or increase ACE inhibitor/ARB (can reduce edema)
4. Switch to verapamil or diltiazem
5. Administer at night
6. Switch to another antihypertensive class

Important Clinical Caveats

• Discontinuation rate: Only 1.5% of patients discontinue amlodipine due to adverse effects, similar to placebo 1
• Laboratory effects: Amlodipine does not cause clinically significant changes in routine laboratory tests, including electrolytes, glucose, lipids, or renal function 1
• Contraindications in heart failure: While amlodipine is reasonably well-tolerated in mild LV dysfunction, other calcium channel blockers (diltiazem, verapamil, nifedipine, felodipine) should be avoided in heart failure with reduced ejection fraction 7
• Pregnancy: Limited safety data exists, though no heightened risk of major congenital malformations has been identified 8