| Drug Class |
Calcium‑channel blocker (dihydropyridine) |
| Common Uses |
• Primary or secondary hypertension
• Coronary artery disease (stable angina, Prinzmetal’s angina)
• Prevention of angina episodes in patients on nitroglycerin |
| Typical Starting Dose |
2.5 mg once daily (usually in the evening). For hypertension, many patients need 5 mg or more; for angina, 5 mg or 10 mg may be started. |
| Dose Adjustments |
Increase by 2.5 mg increments at 2‑4 week intervals based on BP/angina control and tolerance. Max usual dose: 10 mg daily. |
| Mechanism of Action |
Blocks L‑type calcium channels in vascular smooth muscle → vasodilation of arteries → ↓ systemic vascular resistance and BP. In cardiac myocytes, reduces calcium influx → ↓ myocardial contractility & oxygen demand. |
| Onset & Duration |
Peak effect 6–10 h; effect lasts ~24 h. |
| Common Side Effects |
• Peripheral edema (especially lower limbs)
• Flushing, warmth, headache, palpitations
• Nausea, dizziness, fatigue |
| Serious (but uncommon) Risks |
• Severe hypotension, especially when combined with other antihypertensives
• Angioedema (rare)
• Heart failure exacerbation if used in patients with severe left‑ventricular dysfunction (use cautiously) |
| Contraindications |
• Severe aortic stenosis or decompensated heart failure
• Known hypersensitivity to amlodipine or any excipients |
| Key Drug Interactions |
• CYP3A4 inhibitors (ketoconazole, clarithromycin, ritonavir) → ↑ amlodipine levels, ↑ edema/hypotension.
• CYP3A4 inducers (rifampin, carbamazepine, phenytoin) → ↓ amlodipine levels, ↓ efficacy.
• Beta‑blockers → additive blood‑pressure lowering; may mask tachycardia.
• Digoxin → ↑ digoxin levels when combined with other calcium‑channel blockers, though amlodipine alone is usually fine.
• Nitrates (nitroglycerin, isosorbide dinitrate) → risk of severe hypotension. |
| Monitoring Recommendations |
• Baseline and periodic BP & pulse.
• Check for edema and signs of fluid overload.
• If using with nitrates, monitor for orthostatic hypotension.
• In patients with CKD or liver disease, dose adjustment may be needed (often still 2.5–5 mg, but start low). |
| Special Populations |
• Pregnancy – Category C. Use only if benefits outweigh risks; discontinue if pregnancy is detected.
• Breastfeeding – Limited data; generally considered safe but discuss with a provider.
• Elderly – Start lower; watch for orthostatic hypotension. |
| Adherence Tips |
• Take at the same time each day; evening is common due to flushing at night.
• Use a pillbox or set a daily alarm.
• If you miss a dose, take it as soon as you remember—don’t double‑dose next time. |
| What to Do If You Miss a Dose |
• Take it when you remember.
• If it’s almost time for your next dose, skip the missed one and resume the regular schedule.
• Never double‑dose. |