MT1

Question 1

Volume of Distribution (Vd)

Answer 1

Vd = dose of drug / measured conc.

Question 2

Half Life

Answer 2

t1/2 = (0.693*Vd) / CL (clearance)

Question 3

Factors affecting Distribution

Answer 3

1. organ blood flow
2. molecular size ex. heparin
3. lipid solubility (*brain)
4. plasma protein binding (10-99%)

Question 4

Metabolism

Answer 4

Liver via 2 processes:
Phase 1: Biotransformation
*oxidative / reductive / hydrolytic rxns –> P450 (CYP) monooxygenase system
Phase 2: conjugation rxns –> liver enzymes

Question 5

Metabolism Phase II

Answer 5

commonly added molecules
- glucuronic acid
- sulfate
- carboxylic acid

Question 6

Excretion (kidney - renal)

Answer 6

1. passive glomerular filtration
2. active tubular secretion
3. passive tubular reabsorption (urine pH is key)

Question 7

Excretion (bile)

Answer 7

Liver –> intestine via common bile duct
- larger drugs
- conjugated metabolites
(carrier mediated process)

Question 8

Viral Replication

Answer 8

APURAR

Question 9

Covid-19 virus

Answer 9

• ssRNA
• 125nm diamter
• genomic proofreading mech.

Question 10

RDRP inhibitors

Answer 10

• remdesivir
• ribavirin
• favipiravir

MOA: RDV-TP resembles ATP and competes w the nucleotide during viral RNA synth. RDV-TP forms phosphodiester bond w next nucleotide

Question 11

MIC vs MBC

Answer 11

MIC: lowest conc. of antibiotic that inhibits visible growth of a microorganism after overnight incubation
MBC: min bacteriocidal conc.
MBC:MIC
- less than or equal to 4 is bacteriocidal
- over 4 is bacteriostatic

Question 12

b- lactam antibiotics

Answer 12

Penicillin
MOA: inhibits synth of bacterial PG cell wall

Question 13

Macrolides (antibiotic)

Answer 13

Azithromycin (product of actinomycetes)
MOA: inhibits bacterial protein synth by binding reversibly to 50S ribosomal subunit

Question 14

Aminoglycosides (antimicrobial)

Answer 14

Gentamicin
MOA:
- interferes w bacterial protein synth by irreversibly binding 30 and 50S subunits
- creates fissures in outer membranes of bacteria

Question 15

Tetracyclines (antimicrobial)

Answer 15

Doxycycline
MOA:
- inhibits bacterial protein synth by binding REVERSIBLY to 30S subunit (and possibly 50S)
- cause changes in cytoplasmic membrane

Question 16

Sulfonamides (antimicrobial)

Answer 16

Sulfamethoxazole
MOA: interferes w folic acid synth by inhibiting dihydropteroate synthetase and prevents addition of para-aminobenzoic acid (PABA) into folic acid

Question 17

Quinolones (antimicrobial)

Answer 17

Ciprofloxacin
MOA: inhibits DNA gyrase/ topoisomerase

Question 18

Glycopeptides (antimicrobial)

Answer 18

Vancomycin
MOA: inhibits cell wall synth in gram + bacteria by binding to the D-alanyl-D-alanine terminus of cell wall precursor units

Question 19

Oxazolidinone (antimicrobial)

Answer 19

Linezolid
MOA: inhibits protein synth by binding at the P site of the 50S ribosomal subunit

Question 20

TNM classification of solid tumours

Answer 20

T: extent of primary tumour (size)
N: presence/absence and extent of regional lymph node metastasis
M: presence/absence of distant metastasis

Question 21

Chemotherapy

Answer 21

MOA: damage DNA/ interfere with DNA synthesis
- phase specific vs nonspecific agents
- most cytotoxic to cells w high growth fraction

Question 22

Akylating agents (chemotherapy)

Answer 22

Cyclophosphamide
MOA: bind DNA by creating covalent bonds that cross-link DNA –> prevents unwinding of DNA –> decreased protein synth.

Question 23

Epipodophyllotoxins (chemotherapy)

Answer 23

Etoposide
MOA: inhibits topoisomerase II, inhibits DNA synth.

Question 24

Taxanes (chemotherapy)

Answer 24

Docetaxel
MOA:
- promotes assembly and stabilization of microtubules (prevents cell replication)
- may also inhibit angiogenesis (blood vessel formation)

Question 25

Antimetabolites (chemotherapy)

Answer 25

5-Fluorouracil (5-FU) MOA: - resemble naturally occurring nuclear structural components - incorporate into DNA or RNA - may also inhibit enzymes involved in synthesis of DNA or proteins (ex. polymerase)

Question 26

Antitumour antibiotics (chemotherapy)

Answer 26

Doxorubicin MOA: - insert bw DNA base pairs, uncoil DNA, inhibit synth - may also inhibit polymerase

Question 27

Alkylating agent + antitumour antibiotic

Answer 27

Streptozocin - naturally occurring methylnitrosurea - specific for b and exorine cells of pancreas due to an attached sugar moiety MOA: undergoes spontaneous decomp. --> reactive methylcarbonium ions --> alkylate DNA --> interstrand cross links --> inhibits mitosis

Question 28

Camptothecins (chemotherapy)

Answer 28

Irinotecan MOA: bind topoisomerase I, prevents religation of DNA strand - results in cell death

Question 29

Vinka Alkaloids (chemotherapy)

Answer 29

Vincristine MOA: prevent polymerization of tubulin to form microtubules - induce depolymerization of formed tubules - inhibits mitosis

Question 30

Targeted Therapy

Answer 30

Monoclonal antibodies ex. Trastuzumab (Herceptin): Anti-HER2 (breast cancer cells)

Question 31

Endocrine therapy

Answer 31

Aromatase inhibitors ex. Letrozole

Question 32

Catecholamines

Answer 32

- dopamine - NE - epinephrine (all synth. from tyrosine)