PCB Pharmacist Registration flashcards

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

Bioavailability formula

For extravascular dosing, F = (AUC_oral × Dose_IV) / (AUC_IV × Dose_oral). Absolute bioavailability compares an extravascular product with intravenous dosing; relative bioavailability compares two extravascular products.

Half-life relation

For first-order elimination, t½ = 0.693 / k, where k is the elimination rate constant. About 94% of a dose is eliminated after four half-lives and about 97% after five.

Volume of distribution

Vd = Dose / C0 after an intravenous bolus. A value above about 1 L/kg suggests extensive distribution into tissues rather than confinement to plasma.

Clearance relation

Clearance CL = k × Vd = Dose / AUC. For hepatic elimination, the well-stirred model gives CLh = Q × (fu × CLint) / (Q + fu × CLint), where Q is liver blood flow.

Noyes–Whitney equation

Dissolution rate dC/dt = (D·A/h)·(Cs − C), where D is diffusion coefficient, A surface area, h diffusion layer thickness, and Cs saturation solubility. Reducing particle size raises A and the rate.

Higuchi release model

For diffusion-controlled matrix systems, cumulative release Q = kH·t^0.5, so a plot of Q against square root of time is linear. Zero-order release instead follows Q = k0·t.

Henderson–Hasselbalch equation

For weak acids, pH = pKa + log([A−]/[HA]); for weak bases, pH = pKa + log([B]/[BH+]). When pH equals pKa, ionized and unionized fractions are equal.

Percent ionized

For a weak acid, percent ionized = 100 / (1 + 10^(pKa − pH)). For a weak base, percent ionized = 100 / (1 + 10^(pH − pKa)). Ionization strongly affects absorption and renal excretion.

Lipinski Rule of Five

Poor oral absorption is likely when molecular weight exceeds 500, logP exceeds 5, hydrogen-bond donors exceed 5, or acceptors exceed 10. Two or more violations flag a problematic candidate.

Prodrug concept

A prodrug is an inactive derivative that is converted in vivo to the active drug, often by esterase or phosphatase action. It is used to improve permeability, solubility, or targeting.

Bioisosteric replacement

Bioisosteres are groups with similar size and electronic properties that can replace one another with retention of activity. Examples include replacing –OH with –NH2 or –COOH with tetrazole.

Therapeutic index

TI = TD50 / ED50, the ratio of the median toxic dose to the median effective dose. A larger index indicates a wider margin between therapeutic and toxic exposures.

Competitive antagonism

A competitive antagonist binds reversibly at the agonist site and shifts the agonist dose–response curve to the right without reducing maximal response. Higher agonist concentrations can overcome the block.

CYP450 inducers

Rifampicin, carbamazepine, phenytoin, and St John's wort induce cytochrome P450 enzymes and lower concentrations of co-administered substrates. Enzyme inhibitors include ketoconazole, erythromycin, and grapefruit.

Organophosphate poisoning

Organophosphates inhibit acetylcholinesterase, causing muscarinic, nicotinic, and central effects. Atropine blocks muscarinic effects and pralidoxime reactivates the enzyme before aging occurs.

Paracetamol antidote

In paracetamol overdose, the reactive metabolite NAPQI accumulates when glutathione is depleted. N-acetylcysteine replenishes glutathione and is most effective when given within 8–10 hours.

Alkaloid definition

Alkaloids are basic, nitrogen-containing plant secondary metabolites, often pharmacologically active. Examples include morphine from Papaver somniferum, quinine from Cinchona, and atropine from Atropa belladonna.

Cardiac glycosides

Cardiac glycosides such as digoxin and digitoxin consist of a steroid aglycone linked to sugars. They inhibit Na+/K+-ATPase, raising intracellular calcium and increasing cardiac contractility.

Tannins

Tannins are polyphenolic plant constituents that precipitate proteins and have astringent properties. They are classified as hydrolysable (e.g., tannic acid) or condensed (proanthocyanidins).

Anthraquinone laxatives

Senna and cascara contain anthraquinone glycosides such as sennosides. Colonic bacteria hydrolyze them to active metabolites that stimulate colonic motility and secretion, producing a laxative effect.

Prescription parts

A prescription includes the superscription (Rx), inscription (drug and strength), subscription (dispensing directions), signa (patient instructions), and prescriber signature, plus patient identification and date.

Five rights

The five rights of medication administration are right patient, right drug, right dose, right route, and right time. They are a basic safeguard against dispensing and administration errors.

Therapeutic drug monitoring

TDM measures plasma drug concentrations for drugs with narrow therapeutic indices and clear exposure–response relationships, such as digoxin, lithium, phenytoin, and vancomycin, to individualize dosing.

Hospital formulary

A hospital formulary is a continually revised list of selected medicines approved by the Pharmacy and Therapeutics Committee. It guides prescribing, procurement, and stock management within the institution.

Unit dose system

In unit dose distribution, each patient dose is packaged and dispensed ready to administer. It improves accuracy, reduces waste, and supports pharmacist review compared with ward stock systems.

Cold chain

The cold chain maintains vaccines and biologicals at 2–8 °C from manufacture to administration. Freezing must be avoided for adjuvanted vaccines, and temperature is monitored with data loggers.

Heart failure pillars

For heart failure with reduced ejection fraction, four drug classes improve outcomes: ACE inhibitor/ARB/ARNI, evidence-based beta-blocker, mineralocorticoid receptor antagonist, and SGLT2 inhibitor.

Warfarin INR targets

Warfarin therapy is monitored by INR. The usual target is 2.0–3.0 for most indications, while 2.5–3.5 is used for mechanical mitral valves and some recurrent thrombosis cases.

Asthma stepwise therapy

Mild asthma is treated with an as-needed short-acting beta2 agonist; persistent symptoms require regular low-dose inhaled corticosteroid, escalating to combination ICS/LABA and specialist referral as needed.

Gram staining

Gram-positive bacteria retain the crystal violet–iodine complex because of thick peptidoglycan and appear purple. Gram-negative bacteria have a thin layer and outer membrane, counterstain pink with safranin.

Autoclave parameters

Steam sterilization is typically performed at 121 °C and 15 psi for 15–20 minutes. Geobacillus stearothermophilus spores are used as the biological indicator to verify effectiveness.

Vaccine types

Vaccines include live attenuated (BCG, MMR), inactivated (IPV, hepatitis A), toxoid (tetanus, diphtheria), and subunit or conjugate (Hib, pneumococcal). Live vaccines generally require stricter cold chain.

Renal clearance formula

Renal clearance Cx = (Ux × V) / Px, where Ux is urine concentration, V urine flow rate, and Px plasma concentration. Inulin clearance measures GFR; PAH clearance measures renal plasma flow.

Michaelis–Menten equation

Enzyme velocity V0 = Vmax[S] / (Km + [S]). Km is the substrate concentration at half-maximal velocity and is inversely related to enzyme affinity for the substrate.

Acid–base equation

Henderson–Hasselbalch for bicarbonate buffer: pH = 6.1 + log([HCO3−] / (0.03 × PaCO2)). Normal PaCO2 is 35–45 mmHg and normal bicarbonate is 22–26 mmol/L.

DGDA role

The Directorate General of Drug Administration in Bangladesh regulates drug registration, manufacturing and retail licensing, inspection, and post-marketing surveillance to ensure safety, efficacy, and quality of medicines.

Drugs (Control) Ordinance 1982

This Bangladeshi ordinance provides for control of drug manufacture, import, sale, and distribution. It empowers authorities to cancel licences, recall products, and regulate prices of essential medicines.

Pharmacovigilance reporting

Suspected adverse drug reactions should be reported to the national pharmacovigilance centre. Serious reactions are reported promptly, and fatal or life-threatening cases require immediate notification.