Central-acting agents are medicines that slow the heartbeat and lower blood pressure. They block the signals from the brain to the nervous system that narrow blood vessels and make the heart beat faster. As a result, the heart does not pump as hard. Blood flows more easily through the body's veins and arteries. This makes blood pressure go down.

Central-acting agents also are called:

• Central adrenergic inhibitors.
• Central alpha agonists.
• Central agonists.

Several central-acting agents are available. The best one for you depends on your health and the condition being treated.

Examples of central-acting agents include:

• Clonidine (Duraclon, Nexiclon XR).
• Guanfacine (Intuniv).
• Methyldopa.

Central-acting agents are often used with other medicines if the other medicines have not helped lower blood pressure.

Central-acting agents also may be used to prevent, treat or improve symptoms of other health conditions, such as:

• Attention-deficit/hyperactivity disorder (ADHD).
• Medicine withdrawal, such as from opioid pain medicines.
• Hot flashes in menopause.
• Tourette syndrome.

Central-acting agents can have strong side effects. Some possible side effects are:

• Slow heart rate.
• Constipation.
• Dizziness.
• Extreme sleepiness.
• Dry mouth.
• Extreme tiredness.
• Fever.
• Headache.
• Trouble getting erections, also called erectile dysfunction or impotence.

Do not suddenly stop taking a central-acting agent. Doing so can cause a dangerous increase in blood pressure. Do not stop taking these medicines without talking with your healthcare professional.

Talk with your healthcare team if you have any questions about the medicines you take.