Drug Adverse Effects and Interactions Flashcards
Carcinogenic effect
cause cancer
Teratogenic effect
birth defects
QT interval interference
cardiac
Side effect
unavoidable secondary effect @ therapeutic doses
Toxicity
ADR caused by excessive dosing
Allergic reaction
an immune response, mild to severe
Idiosyncratic effect
uncommon response - genetic predisposition
Teratogenic effect
drug capable of causing birth defects
Intensification of effects
increase power- sulbactam and ampicillin
decrease power - aspirin and warfarin
Inhibitory
interactions that result in reduced drug effects
Intensification of effects
increase therapeutic effect, increase adverse effect
Reduction of effects
reduce therapeutic effects, reduce adverse effects
Pharmacokinetic interactions
altered renal excretion and altered metabolism
Combined toxicity
drugs with overlapping toxicities should not be used together
Never combine drugs
in the same container without establishing compatibility
Do not run IV medications
together without establishing compatibility
Altered distribution
Competition for protein binding
Drug interactions have the potential
to significantly affect the outcome of therapy
response may be increased or reduced
The risk for serious drug interaction
is directly proportionate to the number of drugs a patient is taking
Interactions are especially important for drugs with
low therapeutic index - more dangerous
Minimizing adverse drug-drug interactions
thorough drug history, adjust the dose, adjust the timing, monitor, low therapeutic index high monitor
The grapefruit juice effect
inhibits the metabolism of certain drugs
raises the drugs’ blood levels
MAOIs and tyramine-containing foods
“cheese effect” - theophylline and caffeine, potassium-sparing diuretics and salt substitutes
Drug action
warfarin and food rich in vitamin K
Vitamin K
aids in clotting and diminishes the effectiveness of warfarin
Antidote to warfarin
vitamin k
Herbal preparations
can interact with conventional drugs
St. John’s Wort
induces drug-metabolizing enzymes and reduces the blood levels of many drugs
Allergic reactions - If no previous exposure
reactions generally occur several days into treatment
Allergic reaction prepare
patient teaching, prevention, emergency management, epinephrine (epi-pen)