Pharm 2c Flashcards
Give an example of a specific 5HT3AR antagonist and its side effects
ondansetron. Used to treat chemotherapy induced nausea and vomiting
In general, 5HT antagonists have very ‘classic’ side effects eg constipation, headaches.
Give 4 main classes of antiemetic drugs
Antagonists of:
- 5HT3ARs
- H1Rs
- D2Rs
- mAChRs
give an example of a D2R antagonist. What are the side effects of D2R antagonists
Metoclopramide
extrapyramidal side effects (blocks dopamine receptors on extrapyramidal motor pathways) and galactorrhea (dopamine normally inhibits prolactin release)
H1 receptor antagonist (histamine antagonist) and side effects
Promethazine
Histamine H1 receptor antagonists: drowsiness
Muscarinic antagonist and side effect
hyocine
Muscarinic receptor antagonists: drowsiness, dry mouth, constipation
Nb muscarinic antagonists often given together with H1 receptor antagonists for motion sickness = double drowsiness
State the steps involved in the production of THF from PABA.
PABA –> DHOp (enzyme = dihydropterase synthase)
DHOp –> DHF
DHF –> THF (enzyme = DHF reductase)
2 classes of antibiotics that interfere with DNA synthesis
Sulphonamides – inhibits dihydropterate synthase
Trimethoprim – inhibits DHF reductase
Often used together=Co-trimoxazole
List 4 groups of AB drugs that interfere with ribosomes.
Macrolides Chloramphenicol Aminoglycosides Tetracyclines MCAT
Name a group of AB drugs that interfere with RNA synthesis and state its main target.
Rifamycins (e.g. rifampicin) – inhibits RNA polymerase
Which groups of drugs interfere with peptidoglycan synthesis and how do they do this?
Glycopeptides (e.g. vancomycin) – they bind to the pentapeptides and inhibit peptidoglycan synthesis
This is used as a last resort for Gram-positive bacteria that are resistant to other antibiotics
What are beta lactams and what are its 3 subsets
they act by binding to transpeptidase enzyme involved in intergrating PtG into the cell wall.
Cephalosporins
Penicillins
Carbapenems
two main antifungal classes and MOA
azoles and polyenes
Azoles: inhibit ergosterol production
polyenes: These interact with membrane sterols and form channels (punching holes in the membrane)
name two drugs that interfere with cell wall stability
Lipopeptide - (e.g. daptomycin) disrupt Gram +ve cell membranes
Polymyxins - binds to LPS (found in outer membrane of Gram –ve membrane) & disrupts Gram -ve cell membranes
name 2 drugs that are resistant to beta lactamases
Flucloxacillin and temocillin
What drugs commonly cause ADR
Antineoplastics
Cardiovascular drugs
NSAIDs/analgesics
CNS drugs
Name 3 anticholinesterases in the treatment of Alzheimers
Donepezil
Rivastigmine
Galantamine
all 3 above are reversible anticholinesterases (rivastigmine is pseudo-reversible and also inhibits BChE)
Name a NMDAR antagonist and its use
Memantine- use dependent NMDAR antagonist
used for Alzheimers (severe alzheimers, because glutamate receptors will be more activated)
what do first generation and second generation antypsychotics block
first gen- D2 antagonists
Second gen- eg clozapine- 5HT2a antagonism
risperidone 5ht2a antagonism + D2 antagonism
second gen is more ‘messy’
side effects of clozapine
(SWAMP) Side effects: Weight gain Agranulocytosis Myocarditis Potentially fatal neutropenia
4 important dopaminergic pathways in the brain
- Nigrostriatal tract = Substantia nigra to striatum (most important in PD)
- Mesolimbic pathway = VTA to NA
- Mesocortical area = VTA to cerebrum
- Tuberoinfundibular (endocrine)
MAO-B inhibiting drug and what is it used for
selegiline - potentiates action of dopamine by reducing its breakdown by MAO-B. Used in Parkinsons treatment
4 inhalational GA
Nitrous oxide
Diethyl ether
Halothane
Enflurane
2 IV GA
Propofol
Etomidate
Which specific subunits of the GABA-A receptor do IV act on, where are they and what are the effects
Beta 3 subunits – brainstem/spinal cord, activation causes reflex suppression
Alpha 5 subunits – hippocampus, activation causes amnesia
