Drugs That Decrease Heart Rate

Many medications can decrease the heart rate. Drugs are classified according to how they work in the body. Medications that affect the heart rate do so by interfering with or altering how heart cells send and receive electrical impulses. A cardiac impulse is a complicated process involving the movement of electrolytes like calcium and potassium across cell membranes. Many drugs can delay or block this process, causing a slower heart rate.

Antiarrhythmics

Antiarrhythmic medications are a class of drugs used to treat irregular heart rhythms that produce a dangerously fast heart rate. Physicians admit patients to the hospital to begin antiarrhythmic therapy because the risk for dangerous side effects exists until the patient achieves a therapeutic drug level. Patients require close monitoring during initiation of drugs such as amiodarone, flecainide or lidocaine. Although these powerful drugs slow the heart rate, they can cause low blood pressure, chest pain, and other irregular heart rhythms. Patients may take amiodarone and flecainide once sent home to prevent the recurrence of the fast heart rate. Lidocaine is used in emergency situations to slow the heart rate and can only be administered in the hospital setting.

Beta Antagonists

Beta antagonists, also known as beta-blockers, work specifically on heart cells and block the absorption of certain chemicals in the body that normally maintain or increase the heart rate. Beta-blockers like propranolol, metoprolol tartrate and atenolol slow down the heart rate and decrease the strength of heart muscle contraction. In addition to a slow heart rate, low blood pressure frequently occurs as a result of this medication.

Anti-Migraine Drugs

Two drug classifications used to treat vascular migraine headaches are ergot Aakaloids and serotonin 5-HT1 receptor agonists. Ergotamine tartrate and sumatriptan affect absorption of body chemicals that work on cranial blood vessels, however, they have a simultaneous affect on the cardiovascular system. Both medications can cause a transient slow heart rate. A patient receiving one of these drugs requires careful monitoring until the individual's response to the medication is established.

Calcium Channel Blockers

Calcium channel blockers delay the movement of calcium across heart cell membranes causing a delay in the transmission of electrical impulses through the heart muscle. A slower heart rate results. Physicians frequently prescribe drugs like diltiazem to treat high blood pressure and irregular heart rhythms.

Digitalis Lanata Cardiac Glycoside

Another commonly prescribed class of drugs used to slow the heart rate is cardiac glycosides. Digoxin, a well known drug from the Digitalis lanata plant, slows down the rate at which an electrical impulse travels through the heart muscle's conduction system. This means the message to beat is delayed, resulting in a slower heart rate. At the same time, digoxin helps the heart beat stronger so although a patient experiences a slower heart rate, the blood pressure remains stable.