Drug Interactions, Contraindications, Allergies Flashcards
What are drug interactions?
The effects that may occur when the drug is given along with another drug, food, or substance.
What can drug interactions cause?
They can make drugs less effective, lead to unexpected side effects, or increase the action of a particular drug.
What are the types of pharmacodynamic drug interactions?
Additive, synergistic, and antagonistic.
What is an additive drug interaction?
Two drugs with similar therapeutic effects result in those effects added together.
What is a synergistic drug interaction?
Two drugs multiply each other’s effects, resulting in an effect that is more pronounced than just two added together.
What is an antagonistic drug interaction?
Drugs effectively counteract each other.
What are pharmacokinetic drug interactions?
Changes that occur in the absorption, distribution, metabolism, or elimination of drugs.
What is a common mechanism for drug interactions?
Changes in drug metabolism.
What happens when drugs inhibit the activity of enzymes or drug transporters?
It results in slow drug metabolism and more pronounced effects.
What happens when drugs induce the activity of enzymes or drug transporters?
It results in more rapid metabolism and less pronounced effects.
What does contraindication infer?
A drug should not be used due to a heightened safety concern for a particular patient.
What are absolute contraindications?
When the medication should never be given, as the risks outweigh the benefits.
What are relative contraindications?
Situations in which the benefits of administering the drug may outweigh the risks.
What are reasons for contraindications?
Allergy, existing health condition, drug interaction, genetics, age or disease-related changes in organ function.
What are types of drug to drug interactions?
Alcohol, antacids, anti-histamines, and beta-blockers.
What is the interaction between alcohol and drugs?
Additive depression (somnolence) with opiates, benzodiazepines, muscle relaxants, and hepatotoxicity (acetaminophen).
What do antacids do in drug interactions?
They reduce the ability of the other drug to be absorbed into the body.
What is the effect of anti-histamines in drug interactions?
They can have additive sedative effects with other sedating medications.
What is the effect of beta blockers in drug interactions?
Beta blockers can mask symptoms of hypoglycemia from insulin and lead to dangerous bradycardia when combined with other drugs that lower heart rate.
What is the effect of metronidazole?
It inhibits metabolism of alcohol; consumption can cause severe illness when taking metronidazole.
What are the effects of NSAIDs (Nonsteroidal anti-inflammatory drugs)?
They increase the risk of bleeding with anticoagulants and antiplatelets and reduce the effectiveness of anti-hypertensives.
What is the effect of ritonavir?
It increases the toxicity of many drugs by inhibiting metabolism.
What do SSRIs (Selective serotonin reuptake inhibitors) cause when combined with other drugs?
They can cause serotonin syndrome when combined with other drugs that increase serotonin levels.
What drugs are prone to drug interaction problems?
Amiodarone, antidepressants, antipsychotics, digoxin, drugs for epilepsy, and warfarin.
