How Do Alpha-2 Adrenergic Agonists Work?

Alpha-2 adrenergic agonists are drugs used to treat attention deficit hyperactivity disorder (ADHD), high blood pressure, and muscle spasticity associated with multiple sclerosis and spinal cord injury. Alpha-2 adrenergic agonists stimulate alpha-2 adrenergic receptors in the central nervous system and decrease sympathetic nervous system activity. Alpha-2 receptors are found on cells in the sympathetic nervous system. The sympathetic nervous system is the part of the nervous system that produces fight-or-flight response and increases heart rate, blood pressure, breathing rate, and pupil size.

Alpha-2 adrenergic agonists are used to treat:

• ADHD
• Muscle spasticity
• Cramps and tightening of the muscles
• Hypertension (high blood pressure)

Side effects of alpha-2 adrenergic agonists include:

• Dizziness
• Lightheadedness
• Headache
• Tiredness
• Sleeplessness
• Nausea and vomiting
• Constipation
• Abdominal discomfort
• Decreased appetite
• Syncope
• Bradycardia (low heart rate)
• Hypotension (low blood pressure)
• Yellowing of skin or eyes
• Increased bruising and bleeding
• Dry mouth
• Mood disorders
• Anxiety
• Blurred vision
• Anaphylaxis (life-threatening allergic reactions)

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 alpha-2 adrenergic agonists include:

• Guanfacine (Intuniv, Tenex)
• Tizanidine (Zanaflex)