Centrally acting alpha2 adrenergic agonists

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Centrally acting alpha2 adrenergic agonists are medications that are primarily used to treat hypertension. There are 3 centrally acting alpha2 adrenergic agonists: clonidine, methyldopa, and guanfacine.

Okay, so normally, neurons in the brainstem carry signals to the spinal cord, where they release the neurotransmitter norepinephrine, which stimulates the sympathetic nervous system, or SNS. This triggers actions like an increase in heart rate and blood pressure, and vasoconstriction.

Now, alpha2 adrenergic agonists, like clonidine, work by selectively stimulating alpha2 receptors in the brainstem which then activate inhibitory neurons that oppose the SNS. This results in reduced sympathetic outflow to the heart and blood vessels, promoting vasodilation, decreased heart rate, decreased blood pressure, as well as decreased cardiac output.

Alright, common side effects of clonidine can include CNS depression, bradycardia, and hypotension. Xerostomia, also known as dry mouth, is common but this usually decreases after 2 to 4 weeks of therapy. And rarely, nausea, taste changes, anorexia, loss of appetite, and even heart failure can occur.

Now, as far as contraindications go, clonidine should be used with caution in older adults due to the high risk of orthostatic hypotension and CNS depression. In patients with altered renal function, the dosage of clonidine should be reduced, and the patient should be monitored closely. Clonidine should also be avoided in patients with a history of addiction or drug misuse, since clonidine can be used to intensify effects like euphoria. Clonidine should also be avoided in pregnancy and during breastfeeding. Lastly, clonidine is considered a high alert medication, meaning there is an increased risk of causing significant harm if used in error. Regarding interactions, excessive hypotension could result if clonidine is combined with other antihypertensive medications; and combining clonidine with beta blockers can potentiate bradycardia. Also, medications like tricyclic antidepressants and monoamine oxidase inhibitors can decrease the antihypertensive effect of clonidine.

Alright, when caring for your patient taking clonidine, start by obtaining a baseline assessment focused on the cardiovascular system and vital signs. Also be sure to review their most recent laboratory test results, especially their renal function. Following administration, assess your patient for side effects, and evaluate the effectiveness of therapy.

Finally, when educating your patient about their medication, focus your teaching on safe self-administration. Teach them to take their medication exactly as directed and emphasize that clonidine should never be stopped abruptly due to the potential for rebound hypertension. Also advise them to take their medication at night to offset daytime drowsiness, and to avoid hazardous activities like driving until they adjust to the medication. Also, teach them about other potential side effects like dry mouth, and let them know that taking frequent sips of water and chewing sugarless gum can be helpful.

Alright, as a recap.... Centrally acting alpha2 adrenergic agonists are primarily used to treat hypertension and include clonidine, methyldopa, and guanfacine. Clonidine works by blocking sympathetic outflow from the brainstem, which promotes vasodilation, decreased heart rate, decreased blood pressure, and decreased cardiac output. Common side effects include CNS depression, hypotension, and bradycardia, as well as dry mouth. Nursing considerations for alpha2 adrenergic agonist therapy include establishing a baseline assessment, monitoring for side effects, evaluating the effectiveness of therapy and providing teaching for safe self-administration.