Pharm: Basic Principles Flashcards
Plasma proteins which bind basic protein
Orosomucoid
Excretion of amphetamine is facilitated by acidifying/alkalinizing urine? How about aspirin?
Excretion of a weak base such as amphetamine is faster in acidic urine. Excretion faster in weak acid such as ASA in alkaline urine.
Is retinoic acid for acne given as a topical preparation or a transdermal preparation?
Topical. Topical route includes application to skin or to mucous memorable of the eye, ear, nose, throat, airway or vagina for local effect. Transdermal route involves application to skin for systemic effect.
This parameter relates the amount of drug in the body to the concentration in the plasma
Volume of distribution
The concentrations of these three drugs decrease in a linear fashion over time
Zero order kinetics
Ethanol
Phenytoin
Aspirin
Identify which type of antagonism exists.
- Pralidoxime + malathion
- Secretin + gastrin
- Atenolol + dobutamine
- Chemical
- Physiologic
- Pharmacologic
T/F. The higher the therapeutic index, the safer the drug
True. Therapeutic index is the ratio of the TD50 to the ED50. A safe drug is expected to have a very large toxic dose and a much smaller effective dose.
Most common type of drug receptors in the body
G-protein coupled receptors
This describes the time required for the amount of drug in the body or blood to fall by 50%. For drugs eliminated by ____ kinetics, this number is a constant regardless of the concentration.
Half-life.
First-order kinetics
A 100 kg man takes in wonder drug X, a drug which is completely retained in the plasma compartment. In this instance, what is the volume of distribution.
4L.
Vd is equal to the plasma volume if the drug is completely retained in the plasma compartment. Plasma volume is about 4% of body weight.
What is the formula for half-life
(0.693 x Vd) / Cl
Quinacrine is a drug avidly bound in peripheral tissues. Do we expect the Vd of the drug to be greater or lesser than the physical body volume?
Greater. Drug would have a low plasma drug concentration.
Vd = (Amount in the body) / (plasma concentration)
How many half-lives of dosing at a constant rate are considered adequate to produce the effect to be expected at steady state?
3 - 4 half lives
What is the formula for maintenance dose? Loading dose?
Maintenance dose =
( Cl x desired concentration ) /
Bioavailability
Loading dose formula as above but change Cl to Vd
T/F. The therapeutic window is the safe range between the maximum therapeutic concentration and the minimum toxic concentration.
F. It is the difference between the MINIMUM therapeutic and toxic concentrations.
