FPGEE flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Henderson-Hasselbalch equation

For a weak acid, pH = pKa + log([A−]/[HA]); for a weak base, pH = pKa + log([B]/[BH+]). It predicts the ionized versus un-ionized fraction at a given pH.

Volume of distribution

Vd equals the amount of drug in the body divided by plasma concentration. A large Vd indicates extensive tissue binding or distribution, which limits removal by hemodialysis.

Drug clearance

Clearance is the volume of plasma cleared of drug per unit time. After an intravenous dose, CL = dose/AUC, and it determines maintenance dosing at steady state.

Oral bioavailability

F is the fraction of an administered dose reaching systemic circulation intact. It is calculated as (AUCoral × doseIV)/(AUCIV × doseoral) and is reduced by first-pass metabolism.

Elimination half-life

t1/2 = 0.693 × Vd/CL. It is the time for plasma concentration to fall by half; approximately four to five half-lives are needed to reach steady state.

First-pass metabolism

Presystemic metabolism of an orally absorbed drug in the intestinal wall or liver before it reaches systemic circulation, lowering oral bioavailability. Intravenous, sublingual, and transdermal routes bypass it.

Minimum inhibitory concentration

The lowest antimicrobial concentration that prevents visible growth of a standardized bacterial inoculum. It is used with PK/PD indices such as time above MIC or AUC/MIC.

Therapeutic index

TI = TD50/ED50, the ratio of toxic to effective dose. A larger index indicates a wider margin of safety; narrow-index drugs require therapeutic drug monitoring.

Competitive antagonist

Binds reversibly at the same receptor site as the agonist, shifting the dose-response curve right and raising EC50 without changing maximal efficacy; high agonist concentrations can overcome it.

Noncompetitive antagonist

Binds at a site other than the agonist binding site or irreversibly, reducing maximal efficacy (Emax) and potentially potency; increasing agonist concentration cannot fully reverse it.

Zero-order elimination

A constant amount of drug is eliminated per unit time because metabolic pathways are saturated. Half-life increases with concentration; examples include phenytoin, ethanol, and high-dose aspirin.

CYP3A4 inhibitors

Drugs or foods that decrease CYP3A4 activity and raise levels of CYP3A4 substrates. Examples include ketoconazole, clarithromycin, ritonavir, and grapefruit juice.

Prodrug

An inactive compound converted in vivo by metabolism to an active drug. Examples include enalapril to enalaprilat and codeine to morphine.

N-acetylcysteine antidote

A glutathione precursor used to treat acetaminophen overdose. It replenishes hepatic glutathione and detoxifies the reactive metabolite NAPQI, especially when given early.

Vancomycin AUC/MIC target

For serious MRSA infections, the target AUC24/MIC is 400–600. AUC-guided dosing is preferred over trough-only monitoring to balance efficacy and nephrotoxicity.

Warfarin INR targets

Most atrial fibrillation and venous thromboembolism indications target INR 2.0–3.0. A mechanical mitral valve typically requires INR 2.5–3.5.

Metformin first-line therapy

Metformin is first-line pharmacotherapy for type 2 diabetes unless contraindicated. It is avoided when eGFR is below 30 mL/min/1.73 m² because of lactic acidosis risk.

Heart failure GDMT

Guideline-directed therapy for HFrEF combines an ARNI, ACE inhibitor, or ARB with a beta-blocker, mineralocorticoid receptor antagonist, and SGLT2 inhibitor to reduce mortality.

Cockcroft-Gault equation

Estimates creatinine clearance: [(140 − age) × weight in kg]/[72 × serum creatinine in mg/dL], multiplied by 0.85 for women. It is commonly used for renal dose adjustment.

CHA2DS2-VASc score

Estimates stroke risk in nonvalvular atrial fibrillation using congestive heart failure, hypertension, age, diabetes, stroke, vascular disease, and sex; higher scores favor anticoagulation.

Beers Criteria

A list of potentially inappropriate medications for adults aged 65 and older, organized by drug class and clinical concern, used to reduce adverse drug events.

Incremental cost-effectiveness ratio

ICER = (cost of intervention − cost of comparator)/(effect of intervention − effect of comparator). It expresses the added cost per additional health outcome, such as per QALY gained.

Quality-adjusted life year

A QALY equals one year in perfect health. It is calculated as time in a health state multiplied by a utility weight from 0 (death) to 1 (perfect health).

Cost-minimization analysis

A pharmacoeconomic method used when two treatments are assumed to have equivalent clinical outcomes; only costs are compared to identify the less expensive option.

Sensitivity analysis

A method that varies key model inputs, such as costs or probabilities, to test whether economic conclusions remain robust under uncertainty. One-way and probabilistic approaches are common.

Transtheoretical model

Describes behavior change across precontemplation, contemplation, preparation, action, and maintenance stages. Interventions are matched to the patient's current stage of readiness.

ABC inventory analysis

Classifies inventory by annual value: class A items are about 20% of items but 80% of value and receive the tightest purchasing and control oversight.

Durham-Humphrey Amendment

The 1951 amendment created the prescription versus over-the-counter distinction and authorized oral prescriptions and refills for certain non-controlled medications.

Controlled Substances Act

The 1970 federal law created schedules I through V based on abuse potential and accepted medical use, and established DEA registration and recordkeeping requirements.

Schedule II refills

Schedule II prescriptions may not be refilled; a new prescription is required. Emergency oral prescriptions require a written or electronic follow-up within seven days.

OBRA-90 counseling

Federal Medicaid law requiring pharmacists to offer counseling and maintain patient records, supporting prospective drug utilization review and pharmaceutical care documentation.

USP 797

United States Pharmacopeia chapter setting standards for sterile compounding, including facility design, environmental monitoring, personnel training, and beyond-use dating.