How Do Dihydropyridine Calcium Channel Blockers Work?

Dihydropyridine calcium channel blockers are drugs used to treat high blood pressure and severe angina (chest pain caused by lack of oxygen to the heart muscle). Dihydropyridines are one of the different types of calcium channel blockers; they predominately act on blood vessels with less effect on the heart.

Dihydropyridine calcium channel blockers work by blocking the entry of calcium into the cells through voltage-gated calcium channels present on the cells. Calcium present in the cells is responsible for contractions of the cells and muscles. Blocking the calcium channels located on the smooth muscle of blood vessels decreases calcium levels in the cells and causes vasodilation (widening of blood vessels), so the systemic pressure is decreased and the free flow of the blood to the tissues is increased.

These drugs are further divided into three categories based on their effect on contractility:

• Short-acting (capsule-containing liquid)
• Longer-acting formulations with little cardiac depressant activity
• Long-acting agents with no cardiac depressant activity

Dihydropyridine calcium channel blockers are used to treat:

• Hypertension (high blood pressure)
• Angina
• Tachycardia (rapid heartbeats)
• Neurological deficits due to subarachnoid hemorrhage (uncommon type of stroke caused by bleeding in the space between the brain and its outer coverings)
• Subendocardial ischemia in the presence of critical stenosis (myocardial damage which is often confined to the deep [subendocardial] layer of the muscle of the left lower chamber)

Common side effects of dihydropyridine calcium channel blockers may include:

• Headache
• Flushing (involuntary, temporary reddening of the skin, usually seen in the face)
• Dizziness 
• Lightheadedness
• Blood pressure fluctuation
• Swelling of foot, ankles, and hands
• Heart burn
• Constipation

Serious side effects of dihydropyridine calcium channel blockers may include:

• Bradycardia (low heart rate)
• Tachycardia (rapid heartbeats)
• Peripheral edema (swelling beneath the skin due to accumulation of fluid)
• Reflex tachycardia (rapid beating of heart without any underlying cause)
• Worsening of ischemia (reversible damage to a tissue caused by lack of oxygen)

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of dihydropyridine calcium channel blockers drugs include:

• Aliskiren/amlodipine (Amturnide, Tekamlo)
• Aliskiren/amlodipine/hydrochlorothiazide
• Amlodipine (Katerzia, Norvasc)
• Amlodipine/atorvastatin (Caduet)
• Benazepril/amlodipine (Lotrel)
• Clevidipine (Cleviprex)
• Felodipine (Cabren, Cardioplen XL, Felendil XL, Felogen XL, Felotens XL, Keloc SR, Neofel XL, Plendil, Renedil, Vascalpha)
• Isradipine
• Levamlodipine (Conjupri)
• Nicardipine (Cardene IV, Cardene SR)
• Nifedipine (Adalat, Adalat CC, Afeditab CR, Nifediac CC, Nifedical XL, Procardia, Procardia XL)
• Nimodipine (Nimotop, Nymalize)
• Nisoldipine (Sular)
• Telmisartan/amlodipine (Twynsta)