Drug Interactions, Adverse Drug Reaction Flashcards
Additive drug interaction
1+1=2 If 2 drugs are taken together, the response is the same as if it was just one drug taken.
Potentiate
a+b= B One of the drug’s response is magnified.
Synergism
1+1=5 the response is greater than the 2 drugs taken together.
Antagonism
Blocks the response of one drug. 1+1=0
Idiosyncratic
1+1 =437 anything than what we expected,
Inhibitory
1+1=0.5 response is decreased
Pharmacokinetic Interactions (ADME) Interactions with absorption
Absorption: pH depends on environment, decrease or increase in peristalsis(decrease peristalsis increase chance of absorption), absorbent drugs (Metamucil)
What affects Distribution?
Protein binding- highly protein bound drugs
What affects Metabolism?
CYP450
Factors affectin Excretion
- drugs that decease cardia output affect GFR
- alter the filtration,reabsorption, or active secretion of drugs
- P-glycoprotein: pumps drugs out of cell
- protective mechanism
Pharmacodynamic interations
- interaction of drugs at the same site
- interaction of drugs at separate site
What is Cytochrome P450?
-5 Isoenzymes responsible for the metabolism of most drugs
-CYP1A2
-Cyp3A4
-Cyp2c19
-cyp2d6
-cyp3a4
Inhibitors: more drug available results in toxicity
-Inducers : increase the metabolism of the drug resulting in less drug and response ex: oral contraceptive pills
Drug-Food Interactions
- decreased absorption (delay onset of the drugs)
- increased absorption ( certain types of food and minerals) iron and orange juice
- Gi distress( Take with food to prevent discomfort and ulceration)
Drug food interaction examples
- MAO inhibitors and Tyramine rich foods
- chocolate,beer,aged cheeses,pepperoni, salami, hot dogs, avocados, favs beans
Grapefruit and grapefruit juices?
interacts with the CYP450 metabolism
- major toxicity risk
- calcium channel blockers
- statin drugs
- transplant Drugs
- SSRIs
- Versed (anesthesia procedures)
When to take medication on a empty stomach?
- 1hr before or 2 hours after a meal
- stop tube feedings
What is an adverse drug reaction
Poly pharmacy increases risk of ADR in older adults true of false?
True
What is Toxicity and how to decrease it?
- excessive dosing
- start low and slow in older adults
- lower doses in children
- ethnic have varied responses
Drugs are the leading cause of what type of acute organ failure?
Liver -fatal -toxic products injure liver -nausea, vomit, jaundice -AST and ALT _S/s of hepatitis
What to measure for Kidney toxicity
- BUN
- GFR
- creatinine clearance
How to monitor Bone marrow toxicity?
- monitor CBC
What to look out for in Heart toxicity?
-dysrhythmias increased QT interval
Allergic rxn
- less than 10%
- exposed to allergen first
- intensity of dosage is independent of amount of dose
- PCN,NSAIDS, sulfa drugs
