Block 13 Pharmacology DONE Flashcards
paclitaxel class (2)
microtubule stabilisation, taxoid antineoplastic agent
paclitaxel use (2)
ovarian, breast cancer
paclitaxel MOA (5 steps)
- binds B subunit of tubulin
- hyper stabilises microtubule
- prevents cell from disassembly
- prevents microtubule reorganisation
- ruins cell function as chromosomes can’t move
as well as its main MOA, how else does paclitaxel tackle cancer? (4 steps)
- binds to B-cell leukaemia 2
- blocks its anti-apoptotic function
- cell apopotosis
cisplatin class (1)
antineoplastic alkylating agent
cisplatin use (1)
cancer
cisplatin 3 main mechanisms
- alkyl groups attach to DNA bases, DNA fragmentation, prevents DNA synthesis/RNA transcription
- damages DNA by cross-linking, prevents synthesis
- nucleotide mispairing so mutations
cisplatin MOA summary (4 steps)
- affect DNA so it can’t uncoil
- no DNA replication
- no cell proliferation
- cell death
isoniazid class (2)
bactericidal agent, highly specific
isoniazid use (4)
Mycobacterium tuberculosis, M. bovis, M. kansaii
isoniazid is bactericidal to
rapidly dividing mycobacteria
isoniazid is bacteriostatic to
slow growing mycobacteria
isoniazid is a _____ that must be _____
prodrug, activated
isoniazid is activated by
bacterial catalase
isoniazid MOA (2 steps)
- prodrug activated by bacterial catalase
- inhibits synthesis of mycoloic acids, essential part of cell wall
- disrupts DNA, lipids, carbs, nicotinamide adenine dinucletoide (NAD) synthesis
ethambutol class
bactericidal, oral chemotherapeutic agent
ethambutol is specifically active against
actively growing Mycobacterium, e.g. M. tuberculosis
ethambutol MOA is not fully understood but it is thought to… (5 steps)
- inhibit arabinosyl transferase involved in cell wall synthesis
- cell wall production inhibited
- increased cell wall permeability
- inhibits RNA synthesis
- decreases tubercle bacilli replication
rifampicin class
broad spectrum antibiotic
rifampicin targets what kind of bacteria?
gram positive, gram negative
rifampicin advantages
easily absorbed and distributed
rifampicin MOA (3 steps)
- inhibits DNA-dependent RNA polymerase
- decreased RNA synthesis
- cell death
rifampicin can target ____ but not _____ versions of the DNA-dependent RNA polymerase enzyme
bacterial, but not mammalian
rifampicin is restricted to use mainly on
Mycobacterium
rifampicin is restricted to use mainly on mycobacterial infections because of
emergence of resistant bacteria
rifampicin is metabolised where?
liver
rifampicin is eliminated in
bile, urine
pyrazinamide use
with other drugs, TB
pyrazinamide is active only against
M, tuberculosis
pyrazinamide is only active in what conditions?
slightly acidic pH
pyrazinamide MOA (4 steps)
- activated to Pyrazinoic acid in bacilli
- interfere with fatty acid synthesis so growth and replication
- disrupt membrane potential and energy production needed for survival in acidic infection
- binds to ribosomal protein S1, inhibits trans-translation (so can effect dormant mycobacteria)
ciprofloxacin class
broad-spectrum antibiotic, quinolone
ciprofloxacin targets what kind of bacteria?
gram positive, gram negative
bacteria that are resistant to other antibiotics such as beta-lactams, macrolides, tetracyclines, or aminoglycosides may be susceptible to ciprofloxacin as it has a
different MOA
ciprofloxacin MOA (2 steps)
- inhibits topoisomerase 2 (DNA gyrase) and topoisomerase 4
2. bacteria can’t replicate, repair or recombinate
B2 receptor (agonist) stimulation in the lung causes
relaxation of bronchial smooth muscle, bronchodilation, increased airflow
B2 receptor agonists uses (2)
asthma, COPD
salbutamol class
B2 adrenergic agonist
salbutamol has
2 isomers
2 isomers of salbutamol
- R-isomer, levalbuterol
- S-isomer
R-isomer, levalbuterol of salbutamol is responsible for
bronchodilation
S-isomer of salbutamol is responsible for
increasing bronchial reactivity
salbutamol MOA (7 steps)
- stimulates B2 adrenoreceptor’s adrenergic receptor
- activates adenyl cyclase
- increases cAMP and cAMP-dependent protein kinase A (PKA)
- PKA modulates myosin and lowers Ca2+
- relaxes smooth muscle, bronchodilation
- inhibits release of bronchoconstricting agents
- enhances mucociliary clearance
salmeterol class
B@ adrenergic agonist, LABA
salmeterol has a (structure)
long, lipophilic side chain
salmeterol MOA (5 steps)
- side chain binds near receptors so active part can keep binding/unbinding for more stimulation
- relaxes smooth muscle, bronchodilation
salmeterol should be used
regularly
if used regularly, salmeterol decreases the
number and severity of asthma attacks
salmeterol is not for use in an
asthma attack already started