Adreneric Antagonists

Question 1

Metoprolol (Lopressor)

Answer 1

Class: antihypertensive, antianginal, beta blocker (beta 1 selective)

MOA: blocks stimulation of Beta-1 adrenergic receptors

Pharmacokinetics: Onset- IV immediate, duration- IV 5-8 hrs; HL: 3-4 Hrs

Indications: prevention of MI, hypertension, stable narrow complex tachycardias

AR/SE: bradycardia, CHF, pulmonary edema, fatigue, weakness, hypotension

Contraindications: known allergy, uncompensated CHF, pulmonary edema, cardiogenic shock, bradycardia, heart block

Dosage: MI: 5mg slow IV every 2 minutes for 3 doses

Special Considerations: should not be administered to pts who received IV calcium channel blockers

Question 2

Labetalol (Trandate)

Answer 2

Classification: beta blocker (non-selective), antihypertensive

MOA: blocks the stimulation of beta1, beta2, and alpha1 adrenergic receptors

Pharmacokinetics: onset 2-5 minutes; duration: 2-4 Hours IV; HL: 3-8 Hours

Indications: used to treat Hypertensive Crisis

AR/SE: bradycardia, CHF, pulmonary edema, orthostatic hypotension, fatigue, weakness, dyspnea

Contraindications: known allergy, bronchial asthma/uncompensated CHF/pulmonary edema/cardiogenic shock/bradycardia/ or heart block

Dosage: 20 mg slow IV (over 2 minutes) initially. 40 mg may be given every 10 minutes prn to a total dose of 300 mg

Special Considerations: (P class C)

Question 3

Atenolol (Tenormin)

Answer 3

Class: beta blocker (beta 1 selective), antianginal, antihypertensive

MOA: blocks stimulation of beta 1 adrenergic receptors

Pharmacokinetics: onset: <2 min, duration: 24 Hrs; HL: 6-7 Hrs

Indications: management of hypertension and angina pectoris and prevention of MI, stable narrow complex tachycardias not responding to adenosine.

AR/SE: hypotension, bradycardia, cHF, Pulmonary Edema, erectile dysfunction, fatigue, weakness

Contraindications: known allergy, uncompensated CHF, pulmonary edema, cardiogenic shock bradycardia, or heart block

Dosage: 5 mg IV/IO over 5 minutes; may be repeated at 5 mg in 10 minutes.

Question 4

Esmolol (Brevibloc)

Answer 4

Class: beta blocker (beta 1 selective),antihypertensive

MOA: blocks stimulation of beta 1 adrenergic receptors

Pharmacokinetics: onset: <5 min, duration: 10-30 min; HL: 2-9 min

Indications: management of hypertension , stable narrow complex tachycardias not responding to adenosine., controlling ventricular HR in Afib/Aflutter.

AR/SE: hypotension, bradycardia, cHF, Pulmonary Edema, erectile dysfunction, fatigue, weakness

Contraindications: known allergy, uncompensated CHF, pulmonary edema, cardiogenic shock, bradycardia, or heart block.

Dosage: 500 mcg/kg loading dose over 1 min. followed by 50 mcg/kg/min for 4 minutes.