Drug interaction Flashcards
(91 cards)
Name 3 categories of drug interactions
Incompatibility, Pk interaction, Pd interaction
Two types of incompatibilities
Physical and chemical
Three types of chemical incompat
Precipitation, chelation, binding
Effects of incompatibilities (4)
Damage from toxic compound, particle emboli, change pH leading to tissue irritation, therapeutic failure
Name the 6 drugs incompatible with any others
ADDPNT- aminoglycosides, diazepam, digitalis, pentobarbital, NaHCO3, theophylline
Effect of ket and valium
Precipitate
Effect of doxy and calcium gluconate
Chelation from pH difference
Doxy + anything with a metal ion
Precipitate- poop it out, less efficacy
Name two drugs that interact with IV tubing
Plastic binding- insulin and diazepam
4 changes due to Pk interaction
Change absorption, distribution, metabolism, elimination
What is the most common type of drug interaction
Pk
Omperazole and ketoconazole
Omep increases pH = decreased keto absorption by 50%
Effect of antacids on absorption
Increased pH = decreased abs of weak acids and increased abs of weak bases
Effect of infection or any decrease in pH
Increased abs of weak acids and decreased abs of weak bases
Metaclopramide + digoxin
Increased gastric emptying = dec abs of delayed release Rx
Epinephrine and lidocaine
Increased vasoconstriction leads to prolonged local effect
Insulin and NaCl
Decreased absorption due to pH change leads to hyperglycemia
When two drugs compete for protein binding- what happens
The more potent drug will become even more potent bc it loses the competition for protein binding- increased toxicity risk
Phenobarb and kepra
Phenobarb increases enzymes to speed metabolism- leads to need for 30% more levetiracetam for efficacy
Phenobarb + ammonium chloride
Increased elimination
Phenobarb + NaHCO3
Decreased elimination
Pharmacodynamic effects of interaction
Synergistic or antagonistic
Methods of Pd interaction
Same receptor, common process (diff recep), same final pathway
B blockers and Ca blockers
Bradycardia
