Generic Name

Candesartan

Mechanism

• Selective AT1 receptor antagonist: competes with angiotensin‑II for binding to the AT1 receptor on vascular smooth muscle, myocardium, kidney, and adrenal cortex.
• Resulting effects
• Vasodilation → decreased systemic vascular resistance.
• Inhibition of aldosterone synthesis → natriuresis, decreased sodium retention.
• Modulation of sympathetic tone and neurohormonal pathways → improved cardiac remodeling.

Pharmacokinetics

• Absorption: Oral tablets; first‑pass hepatic metabolism. Peak plasma concentration ≈ 10 min post‑dose.
• Distribution: Extensive; crosses placenta (contraindicated in pregnancy) but not significantly excreted via the breast‑milk route.
• Metabolism: Primarily CYP3A4‑dependent.
• Elimination: ~80 % fecal, ~20 % renal.
• Half‑life: 8–9 h (dose‑dependent).
• Special populations
• CKD: Glomerular filtration impairment leads to accumulation; dose adjustment recommended.
• Hepatic impairment: Mild‑moderate decreases clearance; monitor hepatic function.

Indications

• Hypertension (monotherapy or adjunct).
• Heart failure (NYHA II–IV) – reduces mortality & hospitalization when added to standard therapy.
• Diabetic nephropathy & proteinuric kidney disease – slows progression, especially when combined with ACE inhibitors.

Contraindications

• Pregnancy: Category X – teratogenic; avoid in all trimesters.
• Severe renal impairment (CrCl <30 mL/min) without dose adjustment.
• Hyperkalemia or concurrent use of potassium‑sparing diuretics or potassium supplements.
• Bilateral renal artery stenosis: monitor kidney function, possible dose decrease.
• Hypersensitivity to ARBs or excipients.

Warnings
• Volume depletion (diuretics); monitor blood pressure.
• Drug interactions: CYP3A4 inhibitors (ketoconazole, clarithromycin) ↑ candesartan levels.
• Adrenal suppression: Rare, especially with co‑administration of steroids.

Dosing

Administration: Take once daily, morning or evening. May be taken with or without food; absorption not significantly affected.

Adverse Effects

• Common
• Dizziness, orthostatic hypotension (more common in elderly).
• Headache.
• Fatigue.
• Diarrhea (often mild).
• Serious
• Hyperkalemia—symptoms: muscle weakness, arrhythmia.
• Renal function decline (riser serum creatinine >30 %).
• Angioedema (rare).
• Hepatotoxicity (↑ ALT/AST).

Monitoring

Clinical Pearls

• Diabetic Nephropathy: Initiating candesartan 4 mg daily can reduce proteinuria by 20–30 % over 6 mo; combine with ACE inhibitors only after at least 2 weeks apart (to mitigate hyperkalemia).
• Elderly Patients: Lower starting dose (2–4 mg) reduces orthostatic hypotension incidents; titrate slowly with daily BP monitoring.
• Drug Interactions: Concomitant CYP3A4 inhibitors (e.g., amiodarone) and strong ARB‑enhancers require dose vigilance; consider reducing candesartan or extending interval.
• Breastfeeding: Minimal excretion into milk; safe for nursing mothers (use standard precautions).
• Painful Interstitial Nephritis: Though rare, if unexplained rash, fever, and eosinophilia appear, discontinue immediately and evaluate for acute interstitial nephritis.

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• Reference
• Katzung, B. G., & Trevor, A. J. (2023). *Basic & Clinical Pharmacology*. 15th ed.
• Parry, J., & Gill, D. K. (2022). *Clinical Pharmacology of ARBs*. *Seminars in Nephrology*, 38(4), 290‑301.

*This drug card is intended for educational purposes. Always consult current prescribing information and local guidelines before clinical use.*