Central-acting agents are medicines that lower heart rate and reduce blood pressure. They block the signals from the brain to the nervous system that increase the heart rate and narrow blood vessels. As a result, the heart does not pump as hard. Blood flows more easily through the body's veins and arteries. This lowers blood pressure.

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 (Kapvay, Nexiclon XR).
• Guanfacine (Intuniv).
• Methyldopa.

Central-acting agents are often prescribed in combination with other medicines if other medicines have not helped lower blood pressure.

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

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

Central-acting agents can have strong side effects. Possible side effects include:

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

Suddenly stopping a central-acting agent can cause a dangerous increase in blood pressure. Do not stop taking these medicines without talking to a health care professional.

Talk to your health care team if you have any questions about the medicines you take.