Irbesartan + amlodipine is a combination drug for hypertension that is composed of two medicines: irbesartan and amlodipine. Studies have shown that the combination has more anti-hypertensive effects than when used alone. Irbesartan is an angiotensin receptor blocker while amlodipine is a calcium channel blocker that lowers blood pressure in the blood vessels. The effects of these two drugs are complimentary with each other.