Term
| what is special about the structure of digoxin? |
|
Definition
| unsaturated lactone at C-1 on a steroid ring |
|
|
Term
| mech of action for digitalis |
|
Definition
inhibit Na/K/ATPase, resulting in incr in Na
That sodium acts on Na/Ca exchanger to increase Ca to increase contraction |
|
|
Term
|
Definition
| Ca overload-->delayed after depolarization |
|
|
Term
| Therapeutic use of digitalis |
|
Definition
increases baroceptor sensitivity (PS system)
decreases sympathetic tone
decr in conduction velocity in AV Node
incr. conduction velocity in atrial muscle |
|
|
Term
|
Definition
Kidney excretion
**crosses BBB**
narrow margin of safety- 2 times therapeutic level in serum |
|
|
Term
|
Definition
|
|
Term
|
Definition
disturbed color vision
anorexic nausea vomiting |
|
|
Term
|
Definition
ectopic beats of AV node
incr. automaticity of atria and ventricles
AV block
sinus bradycardia |
|
|
Term
| What should atropine be used for |
|
Definition
|
|
Term
| what should K be used for |
|
Definition
| increased AV nodal or vent. automaticity |
|
|
Term
| What should lidocaine or phenytoin be used for |
|
Definition
| worsening vent arrhythmias |
|
|
Term
| How does the thyroid affect digitalis |
|
Definition
| It affects the renal clearance, leading to toxicity |
|
|
Term
| K, Mg, Ca. How do they promote digitalis toxicity? |
|
Definition
|
|
Term
| What drugs decrease renal clearance of digoxin? |
|
Definition
| Quinidine, propafenone, verapimil |
|
|
Term
| This drug increases renal clearance of digoxin |
|
Definition
|
|
Term
| What are the effects of diuretics on digitalis |
|
Definition
| promote inhibition of Na K ATPase pumpt |
|
|
Term
|
Definition
alters release of NE
interacts w/ alpha and beta 1 receptors |
|
|
Term
|
Definition
| dilate vascular beds w/little effect on heart vessels |
|
|
Term
| High therapeutic doses of Dopamine |
|
Definition
incr heart rate and contractility- decr O2 demand
**a-receptor mediated vasocontriction**
better compared to epinephrine |
|
|
Term
|
Definition
IV infusion to enhance renal perfusion
heart insufficiency or cardiogenic shock |
|
|
Term
|
Definition
analog of dopamine
B1 and 2 stimulation
partial a-agonist |
|
|
Term
| Dobutamine mech of action |
|
Definition
| Does NOT release NE or stimulate dopaminergic receptors |
|
|
Term
| Therapeutic doses of dobutamine |
|
Definition
vasodilation
**better inotropic/chronotropic ration than dopa** |
|
|
Term
| Clinical use of dobutamine |
|
Definition
| superior to dopa for advanced heart failure |
|
|
Term
| Inamrinone and Milrinone mech or action |
|
Definition
| inhibit phosphodiesterase increasing intracellular conc. of cGMP (vasodilation) and cAMP (heart contraction) |
|
|
Term
| Which drug has the shorter half-life? |
|
Definition
|
|
Term
| Clinical use for phospho inhibitors |
|
Definition
| short term support of circulation in advanced heart failure |
|
|
Term
| Side effects of phospho inhibs |
|
Definition
Amrinone (thrombocytopenia)
syncope
nausea
liver toxicity |
|
|
