WHAT ARE CENTRAL ALPHA-2 AGONISTS AND HOW DO THEY WORK?

Alpha-2 agonists or alpha-2 adrenoceptor agonists are drugs used to treat high blood pressure. Centrally acting alpha-2 agonists stimulate alpha-2 adrenoceptors receptors in the central nervous system (brain and spinal cord). Alpha-2 receptors are found on cells in the sympathetic nervous system. The sympathetic nervous system is the part of the nervous system that increases heart rate, blood pressure, breathing rate, and pupil size.

When alpha-2 receptors are stimulated, sympathetic nervous system activity decreases. This decreased sympathetic activity leads to a drop in blood pressure and heart rate.

In addition to high blood pressure, central alpha-2 agonists are used in conditions such as:

• Attention-deficit/hyperactivity disorder (ADHD)
• Spasticity (a muscle control disorder that is characterized by tight or stiff muscles and an inability to control those muscles)
• Opioid dependence
• Alcohol addiction
• Menopause symptoms
• Fibromyalgia (widespread muscle pain and tenderness)

The most common side effects of central alpha-2 agonists include:

• Depression
• Bradycardia (low heart rate)
• Orthostatic hypotension (sudden drop in blood pressure when you stand from a seated or lying down position)
• Constipation
• Nausea
• Gastric upset
• Dry mouth (xerostomia) and dry nasal mucosa (caused by increased vagal activity)
• Impotence
• Fluid retention and edema with chronic use

Rare but serious side effects of central alpha-2 agonists may include:

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.

• Hepatic necrosis (death of liver cells)
• Hemolytic anemia (anemia due to death of red blood cells)

Drug names include:

• Aldomet
• Catapres
• Catapres-TTS
• Clonidine
• Duraclon
• Guanabenz
• Jenloga
• Kapvay
• Methyldopa
• Nexiclon XR
• Wytensin