Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
18 Cards in this Set
- Front
- Back
|
what does the plasma drug concentration _generally_ correlate well with?
|
the effect of the drug
|
|
|
define: volume of distribution
|
the volume that would be required to contain the total amount of absorbed drug in the body at a uniform concentration equivalent to that in the plasma at steady state
|
|
|
equation for volume of distribution
|
Vd = Dose/[Drug]_plasma
|
|
|
how are alcohol and anesthetit gases elimiated?
|
lungs
|
|
|
give an example of an osmotic diuretic
|
mannitol
|
|
|
How are H ions targeted by drugs
|
administratino of ammunium chloride can acidify urine. The ammonium is metabolized to urea and the Cl goes into the urine. Loss of Cl obligates loss of H in urine --> lowered pH
|
|
|
How do drugs target metal ions?
|
chelating EDTA can bind Pb++. Metal ions are frequntly drug targets in poison cases
|
|
|
How does digitalis glycosides work?
|
inhibits membrane enzye Na/K/ATPase --> increases myocardial contractility
|
|
|
explain the mechanism of CHF
|
LV has systplic dysfunction --> not enough CO. To improve this, the heart increase the end diastolic volume, and stroke volume increases. At a certain point, the increase in end diastolic volume cause an increase in LV diastolic pressures. Increased pressures cause increased LA and pulmonary capillary pressures --> interstitial and alveolar edema --> elevated RH pressures --> systemic venous hypertension and peripheral edema
|
|
|
what are cardiac glycosides?
|
positive inotropes --> increased contractile force of myocytes
|
|
|
define: Starling relationship
|
increased streatch of the muscle exposes additioanl sites for calcium binding and for actin-,myosin interaction.
an increase in the end diastolic volume of the LV leads to an increase in stroke volume |
|
|
what are the three key proteins involved in Ca regulation in the sarcolemma?
|
1. Na/K/ATPase (sodium pump)
2. Na Ca exchanger 3. Ca pump |
|
|
what belongs in the cardiac glycoside family?
|
digitalis derivatives: digoxin and digitoxin
non digitalis agents: ouabain |
|
|
what is the most commonly used cardiac glycoside?
|
digoxin
|
|
|
how does digoxin work?
|
inhibits the Na/K/ATPase pump. Intracellular Na levels rise, and the Na Ca exchanger doesn't work as well. You get more Ca intracellularly
During an action potential, there is more Ca available to bind troponin C and tension development during contraction is facilitated Note also: the SR of digoxin-treated cells sequesters more Ca for use in subsequent contraction cycles |
|
|
Define ED_50
|
the median effective dose: the dose at which 50% of the patients will have a response to the drug
|
|
|
Define efficacy
|
the maximum effective of which the drug is capable
|
|
|
how is affinity quantified?
|
by k_D
|
