What are the side effects of amlodipine?

Side Effects of Amlodipine

The most common side effects of amlodipine include peripheral edema (especially in the legs and ankles), dizziness, flushing, headache, fatigue, and nausea. 1

Common Side Effects

Amlodipine, a dihydropyridine calcium channel blocker, is associated with several well-documented side effects that occur with varying frequency:

• Peripheral edema: Occurs in 5.6-14.6% of patients, with higher incidence in women and at higher doses (10.8% at 10mg vs 1.8% at 2.5mg) 1, 2
• Fatigue/tiredness: Affects approximately 4.5% of patients 1
• Dizziness: Occurs in 1.1-3.4% of patients 1
• Flushing (hot or warm feeling in face): 0.7-2.6% of patients, dose-dependent 1
• Nausea: Reported in 2.9% of patients 1
• Palpitations: 0.7-4.5% of patients, more common at higher doses 1
• Abdominal pain: Occurs in 1.6% of patients 1
• Somnolence (extreme sleepiness): 1.4% of patients 1

Gender Differences in Side Effects

Women experience certain side effects more frequently than men 1:

Side Effect	Men (%)	Women (%)
Edema	5.6	14.6
Flushing	1.5	4.5
Palpitations	1.4	3.3
Somnolence	1.3	1.6

Less Common Side Effects

The following side effects occur in less than 1% of patients 1:

• Cardiovascular: Arrhythmias (including ventricular tachycardia and atrial fibrillation), bradycardia, chest pain, syncope, tachycardia, vasculitis
• Neurological: Hypoesthesia, peripheral neuropathy, paresthesia, tremor, vertigo
• Gastrointestinal: Anorexia, constipation, dysphagia, diarrhea, flatulence, pancreatitis, vomiting, gingival hyperplasia
• Musculoskeletal: Arthralgia, muscle cramps, myalgia
• Psychiatric: Sexual dysfunction (male and female), insomnia, nervousness, depression, anxiety
• Respiratory: Dyspnea, epistaxis
• Dermatological: Angioedema, erythema multiforme, pruritus, rash
• Special senses: Abnormal vision, conjunctivitis, diplopia, eye pain, tinnitus
• Urinary: Micturition frequency, nocturia
• Other: Dry mouth, increased sweating, hyperglycemia, thirst

Rare but Serious Side Effects

• Heart attack or worsening angina: Can occur when first starting amlodipine or increasing dose 1
• Gingival hyperplasia: Rare but documented side effect, especially in patients with chronic renal failure 3
• Gynecomastia: Reported infrequently in post-marketing surveillance 1
• Generalized edema: Though less common in pediatric populations, cases have been reported 4

Dose-Related Side Effects

Side effects often show dose-dependency 2:

• Lower doses (2.5-5mg) have significantly lower rates of edema compared to higher doses (10mg)
• Interestingly, headache incidence is actually reduced with amlodipine use compared to placebo (7.9% vs 10.9%), particularly at lower doses

Clinical Pearls and Caveats

1. Edema management: Up to 37% of edema cases may not be directly related to amlodipine 2. Consider starting with lower doses (2.5-5mg) to minimize this side effect.

2. Monitoring recommendations:

   • Check for peripheral edema, especially in ankles and legs
   • Monitor blood pressure in both sitting and standing positions to detect orthostatic changes
   • Periodically check electrolytes and renal function if combined with diuretics 5

3. Special populations:

   • Elderly patients may be more sensitive to side effects; consider starting at 2.5mg daily 5
   • Women have higher incidence of edema, flushing, and palpitations 1
   • Patients with renal impairment may be at higher risk for gingival hyperplasia 3

4. Overdose management includes calcium administration, vasopressors for hypotension, atropine for bradycardia, and high-dose insulin for refractory hypotension 5

5. Contraindications: Amlodipine should be avoided in patients with significant left ventricular dysfunction, though it is considered safer than non-dihydropyridine calcium channel blockers in this setting 5