Alpha-2 adrenergic agonists: Nursing Pharmacology

Notes

ALPHA-2 ADRENERGIC AGONISTS
DRUG NAME	clonidine (Catapres-TTS, Duraclon, Kapvay), guanfacine (Intuniv), methyldopa
CLASS	α2 selective adrenergic agonists
MECHANISM of ACTION	Stimulate presynaptic α2-adrenergic receptors in the CNS → dilates peripheral blood vessels → lowers peripheral resistance → reduces blood pressure
INDICATIONS	Hypertension Clonidine: Pain management (epidural) Attention-deficit / hyperactivity disorder (ADHD) Methyldopa: Hypertensive crisis
ROUTE(S) of ADMIN	Clonidine: PO, TD, Epidural Guanfacine: PO Methyldopa: PO, IV
SIDE EFFECTS	Nausea, vomiting, constipation, dry mouth Bradycardia Clonidine: rebound hypertension when stopped abruptly, CNS depression Guanfacine, methyldopa: orthostatic hypotension, sedation Methyldopa: granulocytopenia, thrombocytopenia, hemolytic anemia, hepatotoxicity, hepatic necrosis
CONTRAINDICATIONS & CAUTIONS	Pregnancy and breastfeeding Children and elderly clients Cardiovascular, cerebrovascular, or renal disease Clonidine: epidural use for obstetrical, postpartum, or perioperative pain management not recommended (boxed warning) Methyldopa: active hepatic disease, MAO inhibitors Drug interactions: Clonidine: verapamil, diltiazem, beta-blockers Methyldopa: lithium, MAO inhibitors, levodopa

NURSING CONSIDERATIONS for
ALPHA-2 ADRENERGIC AGONISTS

ASSESSMENT & MONITORING

Assess

Monitor

CLIENT EDUCATION

Purpose of medication: blood pressure control
Transdermal patch
- Apply every seven days at a consistent time each week
- Apply to a clean, dry, intact and hairless skin
  - Chest or upper arm preferred
  - Rotate the application site
  - Proper disposal of a used patch
Do not discontinue abruptly
- Notify healthcare provider for symptoms of hypertension: sweating, flushing, nervousness, severe headache, blurred vision
Side effects
- Nausea, vomiting, constipation
  - Management: consuming smaller, more frequent meals; increasing fluids, fiber-rich foods
- Dry mouth, suggest
  - Use sugar-free hard candy or gum; frequent sips of water
- Drowsiness
  - Avoid alcohol or other CNS depressants
  - Avoid activities that require alertness
- Dizziness, bradycardia and hypotension
  - Make position changes slowly; use caution when going up and down stairs
Lifestyle modifications for blood pressure management
- Weight loss, smoking cessation, increased physical activity as tolerated, low sodium diet
- Blood pressure self-monitoring
  - Abnormal readings that warrant medical attention

Sources

"Focus on Nursing Pharmacology" LWW (2019)
"Pharmacology - A Patient-Centered Nursing Process Approach (8e)" Elsevier Health Sciences (2014)
"Mosby's 2021 Nursing Drug Reference" Mosby (2020)
"Saunders Comprehensive Review for the NCLEX-RN® Examination (7e)" Saunders (2017)

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