Pharmacology Flashcards
Bioequivalence
Relative scale. Generic manufacturers must prove formulation has same bioavailability as brand name formulation.
Bioavailability
Rate and extent the active ingredient is absorbed from drug and becomes available at site of action.
Affected by: route of admin, chemical properties, physiochemical properties, presystemic metabolism, site of drug action, pharmacodynamic parameters
F = amount at receptor/amount given
Biosimilar
Biological product that is highly similar to reference product. Also called “follow-on biologics”
What are 10 most commonly used botanical medicines?
Cranberry, soy, saw palmetto, garlic, ginkgo biloba, milk thistle, echinacea, black cohosh root, St. John’s Wort, ginseng
Why would a practitioner prescribe either rhodora or ashwaganda?
They are adaptogens to help enhance the patients resilience to stress.
List 5 adverse drug-herb interactions
- Grapefruit inhibits CYP3A4 in gut. Increases absorption and decreases excretion.
- Gingko biloba inhibits platelet activating factor. May cause hemorrhage with anticoagulant
- St. John’s wort increases brain serotonin. With antidepressant causes hyper serotonin syndrome
- Garlic induces hepatic CYP3A4
- Pomegranate juice has similar effects to grapefruit.
List three favorable drug-herb interactions
- Milk thistle protects from hepatotoxic effects
- Ginger mitigates chemotherapy side effects of nausea, constipation
- Ginkgo biloba ameliorates sexual side effects of SSRIs
What are the 3 criteria for OTC drug status?
- Indication for use - must be easily diagnosable
- Safety profile - low potential for abuse, few adverse events or interactions
- Practical for OTC use - easy to use and monitor
What are the classes of drugs to treat allergic rhinitis?
- Antihistamine. histamine H1 antagonist. eg: diphenhydramine, loratadine
- Decongestant. α, β antagonist. eg: phenylephrine, pseudoephrine, oxymetazoline
What is the mechanism of acetaminophen?
Inhibits COX1 and COX2 in CNS but not in periphery to achieve pain and fever relief.
Hepatotoxicity occurs when NAPQI accumulates. Stimulate GSH with glutathione precursor N-acetylcysteine to detoxify. Antidote for acute poisoning use acetylcysteine
What are the FDA pregnancy risk ratings for drugs?
A - no risk
B - no evidence
C - risk in animals, no evidence in humans
D - risk in humans, but benefits may outweigh
X - fetal risk outweighs benefits. Contraindicated for pregnancy
What are two major concerns with premature infants?
They have greater skin permeability and fewer plasma proteins which can increase the body’s drug load
What are some patterns of the pharmacokinetics for elderly patients?
Decreased pharmacokinetic factors in clearance. Hard to generalize, but usually kidney problems. If liver problems, phase I reactions affected more than phase II.
What are the types of adverse effects?
- Side effect - predictable due to mechanism of drug, not immune mediated, dose dependent
- Idiosyncratic - not predictable, genetically linked.
- Allergic/hypersensitivity - immune mediated, genetic
What is the difference between a pharmacokinetic and pharmacodynamic drug interaction?
Pharmacokinetic interactions alter ADME, can prolong or decrease effect of drug.
Pharmacodynamic interactions are receptor mediated and alter the efficacy of the drug (additive, antagonistic, synergistic, potentiation). May be reversible, competitive, or non-competitive.
How is adherence measured?
Drug levels, self report, clinical response, medication event monitoring system, pill counts, pharmacy refills.
What kinds of patients are least likely to adhere?
Approx 25% of the population is non-adherent. Patients with chronic illnesses and asymptomatic are least adherent.
How do patients attitudes and perspectives affect adherence?
Intentional non adherence is due to fear or apathy. Non intentional non adherence is due to forgetfulness or factors outside their control.
Chart necessity versus concern.
Adherence requires motivation and ability.
What are some health system barriers to adherence?
Poor provider-patient communication.
Patient’s interaction with health care system
Physician’s interaction with health care system
What are some interventions to promote adherence?
Informational - education
Behavioral - through cues and reinforcement
Family and social - support strategies
Directly observed therapy - ingestion observed by healthcare provider
Federal Food, Drug and Cosmetic Act
1938, gave authority for FDA to regulate food, drug and cosmetic safety in US. Result of disaster involving toxic diligent in liquid sulfanilamide formulation. First piece of legislation requiring that drugs be tested for safety. Mandated that drugs be labeled of contents, bear warning if product habit forming, have adequate directions for use
Durham-Humphrey Amendment
1951, aka prescription drug amendment. Created to allow drugs to be legal. Drugs that were taken under medical supervision given exempt status from safety requirement. Mandated ordering and refilling by licensed prescriber and dispensing by licensed pharmacist. “Legend drugs”
Federal Controlled Substances Act (CSA)
1970, enforced by bureau of narcotics and dangerous drugs in dept of justice. Consolidated all federal laws related to drugs of abuse. Consolidated agencies involved into DEA. Limited handling of certain drugs to individuals registered with DEA
Kefauver-Harris Amendment
1962, aka Drug Efficacy Amendment. Reaction to thalidomide tragedy, need to protect the public. Requires manufacturers to prove efficacy AND safety of drugs. Good manufacturing practices to be followed. FDA controls prescription drug adversities. FDA reviews new drug applications. Mandated informed consent of study subjects, report adverse effects.
