Pharmacokinetics - Drug effects

Question 1

Chelation reactions (drug-drug)

Answer 1

Some drugs contain ions that complex with antibiotics and prevent ABX absorption

Question 2

Example of drug-drug interactions that involve pH reactions

Answer 2

Antifungals are weak bases, and need acidic environment to dissolve. If pt has been taking antacids (alkaline enviro) the antifungals become insoluble

Question 3

Example of drug-drug interactions with GI stuff

Answer 3

If you take a drug to increase GI motility, absorption of other drugs may decrease (because must oral drugs are absorbed in SI)

Question 4

What is an example of a drug drug interaction that involves distribution

Answer 4

If a drug binds or is competitive with an albumin protein, it may inactive another drug.

Question 5

What happens when two drugs compete for the same site on the albumin protein

Answer 5

One drug will bind, which will lower its Vd, and concentration. While the other drug will have a higher Vd and higher concentration.

Question 6

What effect do drug-drug interactions have on metabolism

Answer 6

Some drugs can inhibit or induce CYP450

Question 7

What effects do drug-drug interactions have on excretion

Answer 7

1. Drugs can compete for tubular secretion

2. Drugs can inhibit secretion at renal tubule which can cause toxic build up of another drug

Question 8

What type of pts are at higher risk for drug-drug interactions

Answer 8

1. elderly
2. people taking lots of different meds
3. Kidney failure
4. Liver failure
5. Narrow therapeutic range

Question 9

Overdose

Answer 9

Excessive and potentially toxic amount of meds. Exceeds therapeutic window

Question 10

Allergy

Answer 10

An immune response to a foreign antigen

Question 11

Anaphylaxis

Answer 11

Acute, sudden, and severe allergic reaction between antigen and immunoglobulin IgE bound to mast cells which stimulates the sudden release of immunological mediators

Question 12

Idiosyncratic

Answer 12

Accelerated, toxic, or inappropriate response to usual therapeutic dose in a given pt. Basically an abnormal response for given pt

Question 13

Excessive pharmacologic effect

Answer 13

Getting a much stronger than desired effect from a drug

Question 14

Mutagenic

Answer 14

Agent that causes a genetic mutation (i.e. radiation, UV light)

Question 15

Carcinogenic

Answer 15

Cancer produce substance

Question 16

Teratogenic

Answer 16

Causing abnormal development of the embryo

Question 17

Ways to prevent adverse drug interactions

Answer 17

1. Start low, go slow
2. Determine therapeutic window
3. Understand the receptor binding and structure of the drug (i.e. strong agonist, vs weak vs antagonist)

Question 18

What does the acronym AVOID stand for in pharm

Answer 18

A - allergies
V - vitamins
O - old drugs (and current)
I - interactions
D - Dependence