Combined Alpha- and Beta- Agonists and Antagonists

Question 1

Carvedilol

Indications and MOA

Answer 1

• used for HTN, HF with reduced EF, left ventricular dysfunction following MI
• MOA: nonselective beta receptor blockade and alpha-1 receptor blockade; thereby, decreases BP and peripheral resistance; these combined effects decrease myocardial oxygen demand and lower cardiac workload

Question 2

Carvedilol

Caution and Contraindications

Answer 2

• do not abruptly withdraw
• avoid in patients with bronchospasm
• avoid in severe hepatic impairment
• avoid in patients with 2nd or 3rd degree AV block
• avoid in patients with NYHA Class IV HF
• caution in diabetic patients
• caution in HLD
• other agents preferred in pregnancy and lactation
• initiated by cardiologists in pediatrics
• use caution in elderly patients because of orthostatic hypotension

Question 3

Carvedilol

Adverse Drug Effects

Answer 3

• hypotension, dizziness, fatigue, weight gain, hyperglycemia, headache, n/v, impotence
• anaphylactic reactions (rare)

Question 4

Labetalol

Indications and MOA

Answer 4

• used in HTN, including severe acute
• MOA: nonselective beta receptor blockade and alpha-1 receptor blockade thereby decrease BP and peripheral resistance; these combined effects decrease myocardial oxygen demand and lower cardiac workload

Question 5

Labetalol

Caution and Contraindications

Answer 5

• do not abruptly withdraw
• avoid in patients with bronchospasm
• avoid in severe hepatic impairment
• avoid in patient with 2nd or 3rd degree AV block
• avoid in patients with NYHA Class IV HF
• caution in peripheral vascular disease
• caution in diabetic patients
• caution in HLD
• compatible in pregnancy after the first trimester
• caution in lactation
• limited data available in pediatrics

Question 6

Epinephrine

Indications and MOA

Answer 6

• used for emergency treatment of type 1 allergic reaction, including anaphylaxis
• MOA: decreases vasodilation and vascular permeability that occur during anaphylaxis; it relaxes smooth muscles, relieves bronchospasm, wheezing, dyspnea, pruritus, angioedema, and urticaria

Question 7

Epinephrine

Caution and contraindications

Answer 7

• caution in cardiac disease
• compatible in pregnancy and lactation
• approved in pediatrics

Question 8

Epinephrine

Adverse Drug Effects

Answer 8

• apprehensiveness, tremors, anxiety, weakness, headache, palpitations, angina, alterations in blood sugar, disorientation, HTN