Istin (Amlodipine)

Amlodipine acts on the cardiovascular system to lower blood pressure and improve myocardial oxygen supply.

• Hypertension: reduces systemic vascular resistance to achieve target blood pressure levels.
• Chronic stable angina: improves coronary blood flow to relieve chest pain during exertion.
• Coronary artery disease: helps prevent angina episodes by decreasing myocardial workload.

• Amlodipine selectively inhibits the influx of calcium ions through L-type calcium channels in vascular smooth muscle and cardiac myocytes. This blockade prevents calcium‑dependent contraction, causing vasodilation of peripheral arteries and reducing afterload, which lowers blood pressure and decreases myocardial oxygen demand.

Amlodipine may cause several adverse reactions, ranging from mild to severe.

Common Side Effects

• Headache: mild to moderate intensity, often transient.
• Peripheral edema: swelling of ankles or lower legs.
• Flushing: warm sensation with reddening of skin.
• Dizziness or light‑headedness, especially after standing.
• Fatigue: general feeling of tiredness.

Serious or Rare Side Effects

• Severe hypotension: marked drop in blood pressure requiring medical attention.
• Myocardial infarction: rare occurrence of heart attack.
• Arrhythmias: abnormal heart rhythms, including tachycardia.
• Hepatic dysfunction: elevated liver enzymes or jaundice.
• Allergic reactions: rash, itching, swelling, or anaphylaxis.

When prescribing amlodipine, clinicians should consider several safety measures.

• Blood pressure monitoring: ensure adequate control without excessive drop.
• Hepatic impairment: use caution and consider dose adjustment.
• Concomitant antihypertensives: avoid additive hypotensive effects.
• Heart failure: monitor for worsening symptoms.
• Pregnancy and lactation: safety not established; weigh risks and benefits.
• Store at room temperature: keep below 25 °C, retain in original packaging, protect from moisture and direct sunlight.

Amlodipine can interact with various medicines, altering its efficacy or safety.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., clarithromycin, itraconazole): may increase amlodipine plasma levels.
• Grapefruit juice: can raise drug concentration and risk of hypotension.
• Other potent antihypertensives: may cause excessive blood pressure reduction.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampin, carbamazepine): may reduce therapeutic effect.
• Diuretics: can enhance orthostatic hypotension.
• Beta‑blockers: may require dose titration for combined effect.
• Digoxin: monitor for potential increased serum levels.