4.11 Alpha-2 Antagonists

Clonidine is an Alpha-2 antagonist.

Mechanism of Action:  Clonidine reduces sympathetic outflow from the central nervous system and decreases peripheral resistance and renal vascular resistance.

Indications for Use: Clonidine is used to treat hypertension (HTN) and attention deficit hyperactivity disorder (ADHD).

Nursing Considerations Across the Lifespan: Alpha-2 antagonists can be used safely in pediatric and older adult populations.  For pediatrics, dose adjustments need to be made based on the child’s weight, and titrated slowly.  In older adult populations, dose adjustments are necessary when there is underlying kidney dysfunction.

Nurses need to monitor blood pressure and pulse rate frequently when giving these medications. Dosage is usually adjusted to the client’s blood pressure and can cause hypotension, bradycardia, and sedation. Rebound hypertension may occur if stopped abruptly.

Patient Teaching & Education: Clients should be taught the importance of adhering to the same dosing schedule each day.  Clients may experience orthostatic blood pressure changes and should be cautioned against the use of alcohol while taking this medication.  Additionally, clients may experience increased susceptibility to blood pressure changes when exercising and exposed to hot environments.  If the client experiences mental depression as a side effect of the medication, a different medication therapy may be needed.^[1]

Now let’s take a closer look at the medication grid on clonidine in Table 4.11.^[2][3] Because information about medication is constantly changing, nurses should always consult evidence-based resources to review current recommendations before administering specific medication.

Table 4.11 Clonidine Medication Card

Alpha-2 Antagonists

A2 antagonists are used in research with limited clinical application.^[4]