pharmacology basics

Question 1

example of synergistic action of drugs

Answer 1

aspirin + clopidogrel for acute MI

Question 2

Therapeutic index

Answer 2

median toxic dose / median effective dose

median effective dose (ED50) is the dose that produces a clinically desired effect in 50% of the population that takes it.

(note in graph the dose is in a logarithmic scale)

Question 3

Therapeutic window

Answer 3

The related terms, therapeutic window or safety window, refers to a range of doses that optimize efficacy and toxicity, achieving the most significant therapeutic benefit without resulting in unacceptable side effects or toxicity.

Question 4

What are the phases of drug development

Answer 4

Discovery
Pre clinical research (tested on animals and cell cultures)
clinical research (tested on humans)

Question 5

what are the phases of clinical trial

Answer 5

safety (small size)
efficacy (medium size )
approval (large size- compared with existing drugs)
long term
mnemonic : (SEAL of approval)

Question 6

What are the different names of drugs

Answer 6

Question 7

pharmacodynamics

Answer 7

what the drug does to the body

after the administration of a medication, it binds to receptors or specialized proteins located on the surface of or inside a cell. This gives rise to a signal cascade, which, ultimately, results in some change in the cell’s function, like boosting the production of a particular type of protein or slowing down DNA replication. An ideal medication would produce a single beneficial or therapeutic effect for a certain disease state. In reality, though, most medications produce several unwanted effects, called side effects like nausea or fatigue.

Question 8

pharmacokinetics

Answer 8

what the body does to the drug
absorbption
distribution
metabolism
excretion

Question 9

Low therapeutic index medicines

Answer 9

Commonly used medications known to have a lower TI include warfarin, lithium, theophylline, digoxin, as well as certain antiepileptics

Question 10

loading dose

Answer 10

Question 11

half life of drug

(first order kinetics
excretory rate is proportional to plasma concentration of drug)

Answer 11

half-life is time taken for plasma concentration of a drug to fall by 50%

Question 12

time required for a drug to reach steady state

Answer 12

4-5 half lives

Question 13

adjustments that should be made to the loading dose and maintenance dose to a patient with liver or kidney damage

Answer 13

the clearance value of drug decreases.
therefore maintenance dose should be decreased,
loading dose remains unchanged.

Question 14

bioavailabiliy of intravenously administered drug

Answer 14

100 percent or 1

Question 15

maintenance dose and maintenace dose rate (or infusion rate) equation

Answer 15

maintenace dose rate = excretory rate at steady phase
therefore
maintenace dose rate = plasma concentaration x clearance value of drug

maintenace dose = maintenance dose rate (mg/hr) x dose interval (hr)

It’s important to note that for medications that are not administered intravenously, the dosing rate needs to be divided by the bioavailability to account for the portion of medication that isn’t absorbed into the circulation.