Lebanon Pharmacy Colloquium flashcards

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

Absolute bioavailability formula

F = (AUC oral / AUC IV) × (Dose IV / Dose oral). It compares systemic exposure after extravascular dosing with intravenous exposure, correcting for different administered doses.

Biopharmaceutics Classification System

Groups drugs by aqueous solubility and intestinal permeability into four classes. Class I (high/high) drugs are candidates for biowaivers of in vivo bioequivalence studies.

Noyes–Whitney equation

dm/dt = (D·A/h)(Cs − C). Dissolution rate rises with surface area, diffusion coefficient, and solubility, and falls with boundary-layer thickness.

Higuchi release model

Q = kH·t^0.5 describes diffusion-controlled release from a matrix. A plot of cumulative amount released against square root of time is linear.

Sterility assurance level

A probability of 10⁻⁶ that a single unit is non-sterile after sterilization. For moist heat, F0 ≥ 12 minutes at 121 °C with z = 10 °C is the overkill standard.

Competitive antagonism

The antagonist binds reversibly at the same site as the agonist, shifting the dose–response curve rightward without reducing maximal effect. Higher agonist concentrations surmount the block.

Clearance and half-life relation

CL = k·Vd and t½ = 0.693·Vd/CL. Half-life lengthens when volume of distribution rises or clearance falls, as in hepatic or renal impairment.

Loading dose calculation

Loading dose = (Vd × target concentration)/F. It rapidly fills the apparent volume of distribution; maintenance dosing then depends on clearance.

Narrow therapeutic index drugs

Drugs where toxic and therapeutic concentrations are close, such as digoxin, warfarin, lithium, and phenytoin. They require therapeutic drug monitoring and careful dose titration.

CYP3A4 inhibition

Ketoconazole, clarithromycin, and grapefruit juice inhibit CYP3A4, raising concentrations of statins, tacrolimus, and many calcium channel blockers, increasing toxicity risk.

Lipinski Rule of Five

Predicts oral absorption: molecular weight ≤ 500, log P ≤ 5, hydrogen-bond donors ≤ 5, acceptors ≤ 10. Two or more violations suggest poor bioavailability.

Prodrug concept

An inactive derivative converted in vivo to the active drug, often by esterase hydrolysis. It improves absorption, stability, or targeting, as with enalapril to enalaprilat.

Bioisosteric replacement

Substituting a group with similar size and electronic properties, such as carboxyl with tetrazole or hydroxyl with amino, to retain activity while improving pharmacokinetics or stability.

Phase II metabolism

Conjugation reactions such as glucuronidation, sulfation, acetylation, and glutathione conjugation. They increase water solubility and usually inactive the drug for renal or biliary excretion.

Cardiac glycoside structure

A steroid nucleus, a five-membered lactone ring, and a sugar moiety, found in Digitalis species. They inhibit Na⁺/K⁺-ATPase, increasing intracellular calcium and contractility.

Saponin properties

Steroid or triterpenoid glycosides that foam persistently in water and hemolyze erythrocytes. Ginsenosides from ginseng are triterpenoid examples used as markers.

Pyrrolizidine alkaloid toxicity

Alkaloids in Senecio and comfrey cause hepatic veno-occlusive disease after metabolic activation. They are a classic example of herbal hepatotoxicity.

Standardization marker compounds

Substances used to quantify herbal extracts, such as hypericin in St John's wort or silymarin in milk thistle. The marker is not necessarily the active constituent.

Lebanese Order of Pharmacists

The professional body regulating pharmacy practice in Lebanon. It handles licensure, discipline, and continuing education, and registration is required to practice.

Controlled drug record-keeping

Narcotic and psychotropic medicines require special Ministry of Public Health authorization, official prescription forms, and periodic inventory reconciliation retained for inspection.

Generic substitution conditions

Permitted when the prescriber has not prohibited it and the substitute is bioequivalent and registered with the Ministry of Public Health. The pharmacist must inform the patient.

Teach-back counseling method

The pharmacist asks the patient to restate instructions in their own words. It verifies comprehension of dosing, administration technique, and warning signs before the patient leaves.

Therapeutic drug monitoring indications

Narrow therapeutic index, unpredictable pharmacokinetics, suspected toxicity, or uncertain efficacy. Examples include vancomycin, aminoglycosides, digoxin, lithium, and phenytoin.

Inhaler technique counseling

Demonstrate shaking, exhalation, actuation with slow inhalation, breath-hold, and rinsing after corticosteroids. Distinguish reliever from controller inhalers and check spacer use.

Economic order quantity

EOQ = √(2DS/H), where D is annual demand, S is ordering cost, and H is annual holding cost per unit. It balances ordering and holding costs.

Incremental cost-effectiveness ratio

ICER = (C1 − C2)/(E1 − E2), the extra cost per additional health unit. It is compared with a willingness-to-pay threshold to judge value for money.

ABC inventory analysis

Classifies stock by annual value: A items are high value and tightly controlled, B moderate, C low value. It focuses management effort where financial exposure is greatest.

Paracetamol antidote

N-acetylcysteine replenishes glutathione and detoxifies NAPQI. Treatment is guided by the Rumack–Matthew nomogram using the serum level measured at four hours after ingestion.

Type B adverse drug reaction

Unpredictable, not dose-dependent, and often idiosyncratic or immunologic, such as anaphylaxis or agranulocytosis. They are frequently serious and require withdrawal of the drug.

Serotonin syndrome features

Caused by serotonergic excess, with clonus, hyperreflexia, agitation, and hyperthermia. It contrasts with neuroleptic malignant syndrome, which shows rigidity and elevated creatine kinase.

Incidence versus prevalence

Incidence counts new cases per population at risk over time; prevalence counts all existing cases at a point. For stable disease, prevalence approximates incidence multiplied by duration.

Herd immunity threshold

The proportion needing immunity to interrupt transmission, calculated as 1 − 1/R0. Measles with R0 around 12–18 requires roughly 92–95% coverage.