ALPHA1- AND MIXED ALPHA/BETA-BLOCKERS Antihypertensive drugs belonging to the adrenergic inhibitors (sympatholytics) class. These drugs work to suppress the actions of adrenergic receptors in the sympathetic nervous system, specifically on blood vessels, affecting blood pressure. (Lewis, et al., 2017, p. 690).

ALPHA1- AND MIXED
ALPHA/BETA-BLOCKERS
Antihypertensive drugs belonging to the adrenergic inhibitors (sympatholytics) class. These drugs work to suppress the actions of adrenergic receptors in the sympathetic nervous system, specifically on blood vessels, affecting blood pressure. (Lewis, et al., 2017, p. 690).

Representative Drugs

Alpha1-Blockers: selective activity for alpha1 receptors:

Mixed Alpha/Beta-Blockers: act on alpha1, beta1, and beta2 receptors

Terazosin (HTN; BPH)

Alfuzosin (BPH)

Doxazosin (HTN; BPH)

Tamsulosin (BPH)

Silodosin (BPH)

Carvedilol (HTN)

Labetalol (HTN)

Indications

Mechanism of Action

Contraindications

Pharmacokinetics

Absorption

Distribution

Metabolism

Excretion

Nursing Implications

Patient Teaching

Know the signs & symptoms of orthostatic hypotension: dizziness, lightheadedness on standing)

"First-dose effect"

Reflex tachycardia

Assessment

Labs

(Essential) Hypertension (Burchum & Rosenthal, 2016, p. 157; National Institute of Diabetes and Digestive and Kidney Diseases, 2016).

Reverse Toxicity from Alpha1Agonists (Burchum & Rosenthal, 2016, p. 157).

BPH (Benign Prostatic Hyperplasia) (Burchum & Rosenthal, 2016, p. 158; National Institute of Diabetes and Digestive and Kidney Diseases, 2016).

Pheochromocytoma (Burchum & Rosenthal, 2016, p. 158).

Hypersensitivity (Skidmore-Roth, 2017).

Pre-assessment: Obtain a complete health history including allergies, drug history, and
possible drug interactions. Baseline vital signs particularly BP. (Burchum & Rosenthal, 2016; Skidmore-Roth, 2017).

Post-assessment: BP, allergic reactions (Burchum & Rosenthal, 2016; Skidmore-Roth, 2017).

Evaluation: BP, pulse (rhythm and rate), weight change

Monitor blood pressure - goal is decreased BP in patients with HTN (Burchum & Rosenthal, 2016, 166).

Avoid sudden changes when sitting up or standing to avoid drop in BP; if orthostatic hypotension does occur, sit or lie down (Burchum & Rosenthal, 2016; Skidmore-Roth, 2017).

Few patients faint after the first dose due to severe orthostatic hypotension; dosage starts small and gradually increases (Skidmore-Roth, 2017).

Administered orally and well-absorbed in the GI tract (Burchum & Rosenthal, 2016). Labetalol can also be administered IV, absorbed directly to the blood (Moser et al., 2015. p. 182; Wolters-Kluwer, 2016).

Compensatory increase in heart rate can occur; notify prescriber if this happens. May be treated with a beta-blocker (Burchum & Rosenthal, 2016, p. 157).

May cause Nasal Congestion due to vasodilation of blood vessels in nasal mucosa (Burchum & Rosenthal, 2016, p. 157).

May inhibit ejaculation in males (Burchum & Rosenthal, 2016, p. 157).

Sodium retention

Can lead to compensatory elevation of BP; often combined with a diuretic for patients with HTN (Burchum & Rosenthal, 2016, pp. 157-158).

Vasodilation

Prazosin (HTN)

Take first dose at bedtime

Monitor for improvement of symptoms of BPH - reduction in pain and retention (Burchum & Rosenthal, 2016, 166).

Avoid driving for 12-24 hours after first dose

Most are distributed through protein binding (90%+) (Burchum & Rosenthal, 2016).

Extensively metabolized by the liver (Burchum & Rosenthal, 2016; Moser et al., 2015. p. 182).

Most are excreted through urine and feces (Burchum & Rosenthal, 2016). Labetalol is also excreted in the breast milk (Moser et al., 2015. p. 182; Wolters-Kluwer, 2016).

Renal and liver function tests (Sikdmore-Roth, 2015, 211, 674).

blood glucose

potassium

triglycerides

uric acid

bilirubin

creatinine

sodium

cholesterol

Emphasize the consequences of non-compliance. Not to discontinue drug abruptly, life-threatening dysrhythmia may occur. Effects may take weeks to be evident.
(Burchum & Rosenthal, 2016; Skidmore-Roth, 2017).

Mixed alpha/beta blockers work by blocking properties that are responsible for vasodilation and decreased heart rate. Mixed alpha/beta blockers work by blocking alpha 1, beta 1, and beta 2 in order to promote vasodilation of arterioles and veins and to reduce HR, contractility, and suppress renin release. (Burchum & Rosenthal, 2016, p. 507).

Alpha 1 blockers work by blocking catecholamines (epinephrine and mostly norepinephrine) from reaching the postsynaptic site of alpha 1 receptors on smooth muscle cells, leading to vasodilation in peripheral blood vessels, the bladder neck and prostate (Moser et al., 2015. p. 181).

BUN

Reinforce the need to continue additional therapies for hypertension
(weight loss, sodium restriction, stress reduction, regular exercise, moderation
of alcohol consumption, and smoking cessation). Medication controls but
does not cure hypertension. (FDA, 2016).

1 mg BID/TID and increase to a maximum of 20 mg/day.
For BPH 2 mg BID
(Skidmore-Roth, 2017, pp. 963-963).

8 mg/day with meal. If Creatinine Clearance (CCr) is between 30-49 ml/min give 4 mg/day. <30 ml/min do not give
(Skidmore-Roth, 2017, p. 1070).

References

Patients with diabetes should closely monitor blood glucose, especially if weakness,
malaise, irritability, or fatigue occurs. Medication may mask tachycardia and
increased BP as signs of hypoglycemia, but dizziness and sweating may still occur.(FDA, 2016).

Burchum, J.R., & Rosenthal, L.D. (2016). Lehne's pharmacology for nursing care (9th ed.). St. Louis, MO: Elsevier Saunders.

4 mg/day increasing to 0.8 mg/day if after 2-4 wk
(Skidmore-Roth, 2017, p. 1113).

For HTN 1 mg at bedtime, may increase dosage to desired response but no more than 20 mg/day over a 12 h period.
For BPH 1 mg at bedtime and gradually increase 5-10 mg
(Skidmore-Roth, 2017, pp. 1129-1130).

10 mg/day, after meal
(Skidmore-Roth, 2017, p. 34).

For HTN 1 mg/day h.s. and increase up to 16 mg/day if necessary.
For BPH 1 mg/day h.s. and increase in dosage of 2,4,8 mg at 1-2 wk intervals.
(Skidmore-Roth, 2017, pp 397).

Alfuzosin and Doxazosin may come in extended release tablets. Do not crush.

Raynaud's Disease (Burchum & Rosenthal, 2016, p. 158).

Moser Woo, T., & Robinson, M.V. (2016). Pharmacotherapeutics for advance practice nurse prescribers (pp. 181-183). [Google Books version]. Philadelphia, PA: F.A. Davis. Retrieved from https://books.google.com/books?id=2Q5hCgAAQBAJ&pg=PA182&lpg=PA182&dq=how+are+alpha+1+blockers+absorbed+in+the+body&source=bl&ots=m3N6tcGgMH&sig=nkhn48dhjq2inUy7P6V0g9oIvZg&hl=en&sa=X&ved=0ahUKEwitypP0uP_RAhVC0FQKHcYlCwIQ6AEIRDAG#v=onepage&q=how%20are%20alpha%201%20blockers%20absorbed%20in%20the%20body&f=false

Chronic renal failure (Skidmore-Roth, 2017).

Precaution for pregnant women (Skidmore-Roth, 2017).

Chronic hepatic failure (Skidmore-Roth, 2017).

Precaution for asthma patients when using mixed alpha/beta blockers (Skidmore-Roth, 2017).

Hold the drug and notify the prescriber if pulse <50bpm or systolic BP<90mmHg.(FDA, 2017).

Hold the drug and notify the prescriber if pulse <50bpm or systolic BP<90mmHg. (FDA, 2017).

National Institute of Diabetes and Digestive and Kidney Disease. (2016). Alpha-1 adrenergic receptor antagonists (alpha blockers). U.S. National Library of Medicine. Retrieved from https://livertox.nih.gov/Alpha1AdrenergicReceptorAntagonists.htm

Tabs: 3.125mg, 6.25mg, 12.5mg, 25mg;
ER capsules: 10mg, 20mg, 40mg, and 80mg; 6.25mg PO BID on instances of monitoring standing BP 1 hour after the first dose. If tolerated continue dosage for 7-14 days and may increase to 12.5mg PO BID for 7-14 days following same BP protocol. If tolerated well, may be increased (if needed) to 25mg bid; not to exceed 50mg/day; EXT REL cap 20mg/day, may increase after 7-14 days to 40 mg/day, max 80 mg/day
(Wolters Kluwer, 2016, pp. 278-280).

Wolters Kluwer. (2016). Nursing 2016 drug handbook. Philadelphia, PA: Wolters Kluwer.

Injection: 5mg/mL in 20 and 40 mL multiple-dose vials;
Direct IV route
• Give slow over 2 min at 10 min intervals
Continuous IV INF route
• Diluted in D5W or NNS and use infusion pump; keep patient recumbent during and for 3 hr after administration; monitor VS q5-10min
(Wolters Kluwer, 2016, pp. 810-812).

Tabs: 100mg, 200mg, 300mg;
Adult inpatient: 200mg PO followed by 200 to 400mg PO in 6-12 hours depending on BP response. Increase dose maybe by 200mg PO BID.
Adult outpatient: 100mg PO BID; with or without diuretic; may increase to 200mg BID after 2 days; may continue to increase q2-3 days; max 2400mg/day in divided doses
(Wolters Kluwer, 2016, pp. 810-812).

To report if pregnancy is planned or suspected, avoid breastfeeding.(Sikdmore-Roth, 2015, pp. 210, 672).

Skidmore-Roth, L., (2015) Mosby's nursing drug reference. St. Louis, MO: Elsevier.

Skidmore-Roth, L., (2017) Mosby's nursing drug reference (30th Ed.) St. Louis, MO: Elsevier.

Food and Drug Administration. (2017). MedWatch safety alerts for human medical products. Retrieved from http://www.fda.gov/safety/medwatch/safetyinformation/safetyalertsforhumanmedicalproducts

Lewis, S.L., Bucher, L., Heitkemper, M.M., & Harding, M.M. (2017). Medical-surgical nursing: assessment and management of clinical problems (10th ed.). St. Louis, MO: Elsevier

Xiaotang Jing, Fatmata Kamara, Morgan O'Brien, Brenda Quintana