PCB Pharmacist Registration cheat sheet

Bioavailability (F) = (AUC_oral / AUC_IV) × (Dose_IV / Dose_oral); absolute F compares extravascular to IV, relative F compares two extravascular products.

First-order drug elimination: t½ = 0.693 / k; after 4 half-lives ~94% eliminated, after 5 ~97%, after 7 ~99%.

Volume of distribution Vd = Dose / C0 (IV bolus); large Vd (>1 L/kg) indicates extensive tissue distribution.

Clearance CL = k × Vd = Dose / AUC; hepatic clearance CLh = Q × (fu × CLint) / (Q + fu × CLint) per the well-stirred model.

Noyes–Whitney dissolution rate dC/dt = (D·A/h)·(Cs − C); particle size reduction raises A and dissolution rate.

Higuchi square-root release: Q = kH·t^0.5 for matrix diffusion-controlled systems; zero-order release gives Q = k0·t.

Sustained-release dosing interval: loading dose = (Css × Vd) / F; maintenance rate = (CL × Css) / F.

Sterile filtration uses 0.22 µm membranes for bacteria; 0.45 µm prefilters clarify; 0.1 µm filters retain mycoplasma.

Tablet hardness typically 4–10 kp (or 40–100 N); friability <1% w/w after 100 revolutions at 25 rpm.

Henderson–Hasselbalch: pH = pKa + log([A−]/[HA]) for acids; pH = pKa + log([B]/[BH+]) for bases; equal ionized/unionized when pH = pKa.

For a weak acid, percent ionized = 100 / (1 + 10^(pKa − pH)); for a weak base, percent ionized = 100 / (1 + 10^(pH − pKa)).

Lipinski Rule of Five: MW ≤500, logP ≤5, H-bond donors ≤5, H-bond acceptors ≤10; violation of ≥2 flags poor oral absorption.

Prodrug design masks polar groups (e.g., ester of a carboxylic acid) to improve permeability; hydrolysis in vivo regenerates the active drug.

Bioisosteres: replace –OH with –NH2 or –CH3; replace –COOH with tetrazole; replace phenyl with thiophene to retain activity while altering metabolism.

Ester hydrolysis follows pseudo-first-order kinetics; acid-catalyzed hydrolysis is accelerated by electron-withdrawing substituents and by heat.

Chiral switch: single enantiomer often shows higher potency or lower toxicity than racemate because the eutomer binds the receptor preferentially.

pKa of carboxylic acid ≈4–5; aliphatic amine ≈9–10; phenol ≈10; sulfonamide ≈5–7; these values govern ionization and renal reabsorption.

Receptor occupancy: [LR]/[Rtotal] = [L] / (Kd + [L]); at [L] = Kd, half of receptors are occupied.

Competitive antagonist shifts the agonist dose–response curve right without changing Emax; noncompetitive antagonist lowers Emax.

Therapeutic index TI = TD50 / ED50; a higher TI indicates a wider margin of safety.

Cytochrome P450 inducers: rifampicin, carbamazepine, phenytoin, St John's wort; inhibitors: ketoconazole, erythromycin, grapefruit, cimetidine.

Organophosphate poisoning: acetylcholinesterase inhibition → SLUDGE + nicotinic signs; treat with atropine plus pralidoxime.

Paracetamol overdose: NAPQI accumulates when glutathione is depleted; N-acetylcysteine replenishes glutathione and is most effective within 8–10 h.

Warfarin toxicity is reversed by vitamin K1 (phytomenadione); severe bleeding also requires prothrombin complex concentrate or FFP.

First-pass metabolism reduces oral bioavailability of drugs such as propranolol, lidocaine, and morphine.

Alkaloids are basic nitrogen-containing plant compounds; examples include morphine (Papaver somniferum), quinine (Cinchona), and atropine (Atropa belladonna).

Glycosides yield a sugar plus aglycone on hydrolysis; cardiac glycosides (digoxin from Digitalis lanata) inhibit Na+/K+-ATPase.

Tannins are polyphenols that precipitate proteins; they are astringent and used in wound healing; tannic acid is a hydrolysable tannin.

Essential oils are volatile terpenoids; eugenol (clove), menthol (peppermint), and thymol (thyme) are common examples.

Resins are plant exudates insoluble in water; examples include colophony and myrrh; gum resins contain both gum and resin.

Senna (Cassia angustifolia) contains anthraquinone glycosides (sennosides) that act as stimulant laxatives via colonic irritation.

Digitoxin is more lipophilic and longer-acting than digoxin; both are cardiac glycosides with narrow therapeutic indices.

Pharmacognostic standardization uses organoleptic, microscopic, physical, chemical, and biological methods; ash value and extractive value are key quality parameters.

Prescription elements: patient name, date, superscription (Rx), inscription (drug and strength), subscription (dispensing directions), signa (patient directions), and prescriber signature.

Dispensing errors are reduced by the 'five rights': right patient, right drug, right dose, right route, right time.

Patient counseling should cover indication, dose, administration, common side effects, storage, and what to do about missed doses.

Medication reconciliation is performed at admission, transfer, and discharge to prevent unintended discrepancies.

Pharmacovigilance reporting: serious adverse drug reactions should be reported to the national authority within 15 days; fatal cases immediately.

Adherence can be assessed by pill counts, pharmacy refill records, and validated questionnaires such as the Morisky scale.

Therapeutic drug monitoring is indicated for drugs with narrow therapeutic indices and good exposure–response relationships, e.g., digoxin, lithium, phenytoin, vancomycin.

Pharmacist-led medication review reduces inappropriate polypharmacy in elderly patients using criteria such as Beers or STOPP/START.

Hospital formulary is a continually revised list of selected medicines approved by the Pharmacy and Therapeutics Committee.

Drug distribution systems: unit dose is the safest; ward stock and floor stock are less controlled; automated dispensing cabinets improve accountability.

Intravenous admixture preparation requires laminar airflow hoods and aseptic technique; cytotoxic drugs need a biological safety cabinet.

Community pharmacy stock control uses ABC/VED analysis; 'A' items are high-value and need tight inventory control.

Cold chain storage: refrigerated vaccines at 2–8 °C; avoid freezing; monitor with data loggers and temperature charts.

Controlled substances require double-locked storage, running balance records, and witnessed destruction.

Emergency tray contents typically include adrenaline, atropine, hydrocortisone, and a bronchodilator; check expiry monthly.

Hospital antibiotic stewardship programs use formulary restriction, prospective audit with feedback, and de-escalation based on culture results.

Hypertension first-line in most patients: thiazide diuretic, ACE inhibitor/ARB, or calcium channel blocker; combine agents from different classes.

Type 2 diabetes: metformin is first-line unless contraindicated; add SGLT2 inhibitor or GLP-1 agonist when cardiovascular or renal disease is present.

Asthma stepwise therapy: as-needed short-acting beta2 agonist for mild; add low-dose inhaled corticosteroid; escalate to LABA/ICS combination when needed.

Heart failure with reduced ejection fraction: four pillars are ACE inhibitor/ARB/ARNI, beta-blocker, mineralocorticoid receptor antagonist, and SGLT2 inhibitor.

Warfarin dosing is guided by INR; target 2.0–3.0 for most indications, 2.5–3.5 for mechanical mitral valves.

Vancomycin dosing: target AUC24/MIC 400–600; trough monitoring alone is less preferred; adjust for renal function.

Acute coronary syndrome: dual antiplatelet therapy (aspirin plus a P2Y12 inhibitor) plus statin and anticoagulation as indicated.

Pediatric dose calculations often use weight (mg/kg) or body surface area (mg/m²); Clark's rule uses weight/150 for children.

Gram-positive bacteria retain crystal violet–iodine complex due to thick peptidoglycan; Gram-negative have an outer membrane and appear pink with safranin.

Sterility testing uses direct inoculation or membrane filtration; positive controls and method suitability tests are required.

Autoclaving at 121 °C, 15 psi for 15–20 minutes achieves sterilization; biological indicator is Geobacillus stearothermophilus.

Dry heat sterilization at 160 °C for 2 hours or 170 °C for 1 hour is used for glassware and oils.

Antibiotic mechanisms: cell wall synthesis inhibition (beta-lactams, vancomycin), protein synthesis inhibition (aminoglycosides, macrolides), DNA gyrase inhibition (fluoroquinolones).

Vaccines: live attenuated (BCG, MMR), inactivated (IPV, hepatitis A), toxoid (tetanus, diphtheria), subunit/conjugate (Hib, pneumococcal).

Cold chain for most vaccines is 2–8 °C; varicella and MMR are freeze-dried and reconstituted before use.

Antibody structure: two heavy and two light chains; Fab binds antigen; Fc mediates effector functions; IgM is pentameric and first responder.

Glycolysis yields net 2 ATP and 2 NADH per glucose; Krebs cycle yields 3 NADH, 1 FADH2, and 1 GTP per acetyl-CoA.

Oxidative phosphorylation: each NADH yields ~2.5 ATP and each FADH2 ~1.5 ATP; total ~30–32 ATP per glucose.

Normal fasting plasma glucose 3.9–5.5 mmol/L (70–100 mg/dL); HbA1c <5.7% is normal, 5.7–6.4% prediabetes, ≥6.5% diabetes.

Renal clearance Cx = (Ux × V) / Px; inulin clearance measures GFR; PAH clearance measures renal plasma flow.

Acid–base: Henderson–Hasselbalch pH = 6.1 + log([HCO3−] / (0.03 × PaCO2)); normal PaCO2 35–45 mmHg, HCO3− 22–26 mmol/L.

Cardiac output = heart rate × stroke volume; mean arterial pressure ≈ diastolic + 1/3(systolic − diastolic).

Enzyme kinetics: V0 = Vmax[S] / (Km + [S]); Km is the substrate concentration at half Vmax and reflects affinity.

Osmolarity ≈ 2[Na+] + glucose/18 + urea/2.8 (mg/dL); normal plasma osmolality 275–295 mOsm/kg.

The Directorate General of Drug Administration (DGDA) regulates drug registration, licensing, and post-marketing surveillance in Bangladesh.

The Drugs and Cosmetics Act 1940 and the Drugs (Control) Ordinance 1982 are core legal instruments governing drug manufacture, sale, and import.

Drug manufacturing and retail sale require licences issued by DGDA; a qualified pharmacist must be employed for retail pharmacy operations.

Schedule drugs (prescription-only) must be dispensed against a valid prescription; over-the-counter drugs are listed separately.

Pharmacovigilance in Bangladesh is coordinated by the DGDA Adverse Drug Reaction Monitoring Centre; suspected serious ADRs should be reported promptly.

Narcotics and psychotropic substances are controlled under the Narcotics Substances Control Act 1990; record-keeping and secure storage are mandatory.

Good Manufacturing Practice (GMP) compliance is required for all manufacturers; DGDA conducts inspections and may suspend or cancel licences for violations.

Pharmacy ethics: maintain patient confidentiality, avoid conflicts of interest, dispense only quality-assured products, and report counterfeit or substandard medicines.