Side Effects of Amlodipine 2.5 mg Daily
At the 2.5 mg daily dose, amlodipine is generally well-tolerated with minimal side effects, though peripheral edema remains the most common adverse effect even at this low dose. 1
Common Side Effects at 2.5 mg Dose
The FDA-approved labeling provides specific incidence data for the 2.5 mg dose from controlled clinical trials 1:
- Peripheral edema: 1.8% (compared to 0.6% with placebo) 1
- Dizziness: 1.1% (compared to 1.5% with placebo) 1
- Flushing: 0.7% (compared to 0% with placebo) 1
- Palpitations: 0.7% (compared to 0.6% with placebo) 1
Additional Side Effects (Non-Dose-Related)
Other adverse reactions reported at >1% incidence across all doses include 1:
Gender-Specific Considerations
Women experience significantly higher rates of certain side effects compared to men, even at lower doses 1:
- Peripheral edema occurs in 14.6% of women versus 5.6% of men at therapeutic doses 1
- Flushing affects 4.5% of women versus 1.5% of men 1
- Women have a 2.6-fold increased risk of developing edema compared to men 2
Less Common Side Effects (<1% incidence)
The following occurred in <1% but >0.1% of patients 1:
- Cardiovascular: arrhythmias, bradycardia, chest pain, syncope, tachycardia 1
- Neurological: paresthesia, tremor, vertigo, hypoesthesia 1
- Gastrointestinal: constipation, diarrhea, dysphagia, gingival hyperplasia 1
- Musculoskeletal: muscle cramps, arthralgia, myalgia 1
- Dermatologic: rash, pruritus 1
- Other: sexual dysfunction, insomnia, nervousness 1
Serious but Rare Adverse Effects
Angioedema has been reported in postmarketing surveillance, though causality is uncertain 1. Other rare serious effects include 1:
Important Clinical Considerations
The 2.5 mg dose demonstrates significantly lower side effect rates compared to higher doses - edema increases from 1.8% at 2.5 mg to 10.8% at 10 mg 1. This dose-dependent relationship makes 2.5 mg an appropriate starting dose for most patients 3, 4.
Amlodipine does not cause clinically significant changes in laboratory parameters, including serum potassium, glucose, lipids, or renal function 1. The drug has minimal effects on heart rate and does not alter cardiac electrical conduction 1, 5.
Discontinuation due to adverse effects is rare - only about 1.5% of patients discontinued amlodipine in controlled trials, not significantly different from placebo 1.
Mechanism of Edema
The peripheral edema caused by amlodipine results from preferential dilation of pre-capillary vessels, increasing capillary hydrostatic pressure rather than fluid retention or volume overload 2. This typically affects the lower limbs due to gravitational effects 2.
Tolerability Advantages at Low Dose
Amlodipine's gradual onset of action and long half-life (35-50 hours) contribute to better tolerability compared to other dihydropyridines, particularly regarding vasodilatory side effects like headache, flushing, and dizziness 5, 6. The 2.5 mg dose capitalizes on this favorable pharmacokinetic profile while minimizing adverse effects 3, 4.