Drugs Flashcards
Digoxin
Positive inotropic agent
Blocks Na+K+ ATPase, less NA leaves slowing Na/Ca ATPase.
Protects AV node in patients with co-morbidities of HF and Afib
Digoxin Pharmacokinetics
Variable oral bioavailability depends on dosage form
Renal excretion 70% unchanged
Digoxin precautions
Hypokalemia
AE of digoxin
Altered cognition, visual disturbances ( toxic levels)
bradeycardia /atropine bradycardia
Antidote: digibind
Milirinone
Inodilator –> dual MOA
cAMP +cardiac contractility bc it increases intracellular Ca and accelerates relaxation of smooth and cardiac muscle
Milrinone
Short t1/2 , continuous IV infusion,
renal sufficiency dose adjustment
Milrinone Precautions
Ventricular Tachycardia
EKG monitoring recommended in high risk patient
Vtach
Dobutamine + IV Dopamine MOA
Both are B-1 adrenergic receptor agonists
Dopamine –> dose dependent effects. Not as selective as dobutamine
Activates D1
Activates B1
Dopamine: +renal perfusion at low doses + CO at moderate
Dobutamine Clincal Use
It is only IV infusion
Dobutamine Clinical Use:
IV infusion only, both may cause tachyphylaxis
Dobutamine Adverse Effects
Tachycardia
+Myocardial Oxygen consumption
Use caution in HF patients
Diuretics Clinical
Acute and chronic HF, pulmonary and peripheral edema
What do loop diuretics do?
loop diuretics affect the 1Na/2Cl/1K co-transporter/symporter at the loop of Henle
Butmetanide
Thiazides
Block Na/Cl co-transporter at early distal tubule
Hydrochlorathiazide for mild chronic HF
Vasopressin Antagonists
Aquaretics block V2 receptors at the at the late distal and collecting tubule ot inhibit H2O reabsorption +H2O
Tolvapan–> block N/Cl co-transporter for chornic HF
conivaptan –> IV
Hypokalemia
Angiotensin Antagonists ACEi and ARBs
Prils –> ACE converts Ang 1 and Ang 2
Sartans –> competitive antagonists of the ang 2 type 1 receptor
block ang 2 signaling
Candesartan is considered best choice for HF
contraindicated in pregnancy
Angiotensin Antagonists ACEi and ARBs
AE: Hyper-kalemia,
Ang 2 absense –> orthostatic hypotension
Acute Renal Failure, + bradykinin: ACE and kininase 2 are the same
Captopril Cough
Aldosterone Antagonists: Spironolactone, Eplerenone
Spironolactone: competitive antagonists of the Ang 2 Type 1 receptor
Eplerenone: more selctive w/less side effects
Clinical use: chronic HF w/other recommended therapies
Aldosterone Antagonists: Spironolactone, Eplerenone Adverse Effects
Hyperkalemia
Neprilysin
at least 3 well characterized naturetic peptides
+cGMP potent vasodilator
Neprilysin: enzyme found in many tissues
+ANP
