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Clinical pharmacy 2024/2025 Level 3 Pharm D Pharmacology 1 (PO 502)
7- β-Adrenergic Agonists [Dobutamine]
➢ improves cardiac performance by causing positive inotropic effects and vasodilation
(coronary artery
➢ Dobutamine is the most commonly used inotropic agent other than digoxin
➢ ↑intracellular cyclic adenosine monophosphate (cAMP) ➔ activation of
protein kinase G ➔ phosphorylation of Slow calcium channels ➔ entry
of calcium ion into the myocardial cells ➔ contraction
MOA ➢ Intravenously infusion (in the hospital)
[no effective oral inotropic agents exist other than digoxin]
Not affect oxygen consumption as it acts as dilator for coronary arteries so not
increase oxygen demand.
8- Phosphodiesterase Inhibitors )Inamrinone(
(formerly amrinone) and milrinone
➢ ↑ intracellular concentration of cAMP ➔↑intracellular calcium ➔↑ cardiac contractility.
➢ Both long-term Inamrinone and milrinone ➔ associated with a substantial increase in the
risk of mortality.
➢ However, short-term use of IV milrinone is not associated with increased mortality, and
some symptomatic benefit may be obtained when it is used in patients with refractory
HF. (reserved for refractory HF).
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