Pharmacology Flashcards
mechanism of action on benzodiazepines
GABA A receptor agonist which potentiates effects of GABA nad increased frequency of Cl channel opening (activates Cl channels)
mechanism of action of melatonin
binds to MT1 receptors in suprachiasmic nucleus of anterior hypothalamus and regulates circadian rhythm
mechanism of action of methyphenidate
inhibits reuptake of dopamine and noradrenaline so increases level of dopamine and noradrenaline in basal ganglia
sodium dependent dopamine transporter inhibitor
side effects of methylphenidate
- reduced appetite
- sleep disturbance
- hypertension
mechanism of action of atomextine
noradrenergic effect via alpha and beta receptors
side effects of atomextine
hypertension
tachycardia
stroke, heart attacks
sudden death
mechanism of action of rituximab
targets CD20 surface molecule on B cells
mechanism of action of tociluzumab
acts by inhibiting IL-6 and prevents inflammation
mechanism of action of adalidumab
binds to TNF-alpha and neutralises its bioactivity and causes apoptosis of TNF expressing mononuclear cells
mechanism of action of IV immunoglobulin
blocks fragment crystallisable receptors and reduces haemolysis
mechanism of action of vigabatrin
inactivates GABA transaminase so inhibits GABA breakdown
side effects of vigabatrin
diplopia
reduced peripheral vision
optic neuritis
retinal atrophy
aggression
alopecia
mechanism of action of phenobarbital
binds to GABA -A receptors and prolongs chloride channel opening time and increases threshold for action potential and depressing central nervous system
mechanism of action of phenytoin
blocks voltage gated Na channels and reduces synpatic transmission
side effects of phenytoin
hair changes - excessive hair growth
nystagmus
teratogenic
gingivial hypertrophy
vit D deficiency
mechanism of action of sodium valproate
reduction of catabolism of GABA to increase availability of GABA.
blocks voltage gated Na channels and suppresses neuronal hyperexcaitability
side effects of sodium valproate
- teratogenic
- increased appetite and weight gain
- insulin resistance and metabolic syndrome
- easy bruising
- hair loss
- tremor
mechanism of action of retinoids
vitamin A derivative
features of fetal retinoid syndrome
small low set ears
stenosis of ear canals +/- deafness
microcephaly
celft lip and palate
transposition of great arteries, hypoplastic l heart syndrome
mechanism of action of lidocaine
prolongs inactivation of voltage gated sodium channels which prevents action potentials firing
mechanism of action of bisphosphonates
inhibits osteoclast actvity
mechanism of action of oxybutynin
muscarinic receptor antagonist for acetylcholine which causes relaxtion of bladder smooth muscle to increase capacity
mechanism of action of desmopressin
synthetic analogue of ADH - increases cellular permeability of collecting ducts and increases reabsorption of water
mechanism of action of adenosine
A1 adenosine receptor agonist which reduces conduction time in AV node by inhibiting calcium influx and promoting K efflux
1/2 life of adenosine
10 secs -> give large vein close to heart
mechanism of action of amiodarone
potassium channel blocker which prolongs action potential
side effects of amiodarone
pulmonary fibrosis
hypothyroidism
corneal deposits
photo sensitivity rash
mechanism of action of milrinone (phosphodiesterase 3 inhibitor)
+ve inotrope and vasodilator
competitive phosphodiesterase 3 inhibitor that inhibits degradation of camp and increase cAMP to increase myocardial contractility, promotes myocardial relaxation and reduced vascular tone in circulation
mechanism of action of atropine
blocks vagal impulses
mechanism of action of statins
inhibits HMG Co-a and reduces LDL cholesterol levels
mechanism of action of ezetimibe
inhibits dietary cholesterol absorption in intestine by blocking NPC1L1 at brush border
mechanism of action of trimethoprim
dihydrofolate reductase inhibitor so blocks DNA synthesis
/ inhibition of tetrahydrofolic acid synthesis
side effect: rise of creatinine
side effects of rifampicin
orange bodily fluids
liver dysfunction
potent enzyme inducer (effects INR)
side effects of isoniazid
peripheral neuropathy (vit B6 deficiency)
deranged liver function
agranulocytosis
cutaneous adverse reactions
seizures (if in newborn)
side effects of ethambutol
visual disturbances
ocular toxicty
treatment of TB meningitis
12 months rifampicin and isoniazid
2 months pyrazinamide and ethambutol
initial steroids
mechanism of action of fusidic acid
inhibit protein synthesis (bacteriostatic effect)
mechanism of action of aminoglycoside
eg. gentamicin, amikacin
inhibit protein/ bacterial synthesis (binds to 30S ribosome)
side effects of gentamicin
vestibulo toxicity -> hearing loss
nephrotoxicity
how is heparin monitored
anti Xa levels
antidote of unfractioned heparin
protamine
mechanism of action of ibuprofen
reduces prostaglandin synthesis through non selective inhibition of COX 1 and 2
mechanism of action of osmotic diuretic e.g. mannitol
osmosis in the proximal renal tubule.
does not cross blood brain barrier - increases intravascular volume and promotes fluid shift from brain to blood to prevent cerebral oedema
mechanism of action of potassium sparing diuretics e.g. spironolactone
block action of aldosterone at collecting duct leading to loss of Na and water excretion (retain K and H ions)
mechanism of action of loop diuretics e.g. furosemide, bumetanide
inhibit Na-K-Cl co transporter in thick ascending limp of loop of henle causing loss of Na, K, Cl and water in the urine
side effect of furosemide
metabolic alkalosis
dizziness
headache
hypokalaemia
hyponatraemia
hypocalcaemia
mechanism of action of thiazide diuretics e.g. bendroflumethiazide
acts at proximal part of distal convulated tubule
mechanism of action of prostaglandin E1
acts on E4 receptors on smooth muscle of ductus coupled to Gs GPCR and causes smooth muscle relaxation and patent ductus arteriosus
side effects of prostaglandin E1
apnoea
resp depression
tissue oedema
fever
seizures
side effects of calcium channel blockers
gym hypertrophy (nifedipine)
constipation
bradycardia
hypotension
AV blocker
vertigo
side effects of corticosteroids
1st week - insomnia *, psychosis
prolonged - diabetes, immunosuppression, pathological fractures (osteoporosis)
striae
acne
hypertension
glaucoa
reduction in growth velocity
mechanism of action of low dose of adrenaline
acts at beta 1 adrenoreceptors in myocardium (in the heart) to increase contractility and reduced systemic vascular resistance
mechanism of action of high doses of adrenaline
acts at alpha 1 ** and 2 adrenoreceptors on peripheral vasculature (in veins + arterioles) to cause vasoconstriction to increase systemic vascular resistance (IN ANAPHYLAXIS)
mechanism of action of ipratropium
anti muscarinic bronchodilator and cholingeric receptor blocker
side effects of ipratropium
myodriasis
flushing of skin
hyperthermia
dry skin
agitation
mechanism of action of salbutamol
beta 2 adrenergic receptor agonist
activates adenyl cyclase to form cAMP and relaxes smooth muscle
mechanism of action of montelukast
leukotriene receptor antagonist which reduces bronchoconstriction and inflammation in asthma
indicated , 5 y/o when unable to use iCS
mechanism of action of aminophylline
phosphodiesterase inhibitor (type 3) to relax smooth muscle
mechanism of action of penicillin
inhibit bacterial cell wall synthesis
mechanism of action of quinolones e.g. ciprofloxacin
inhibit DNA gyrase
side effects of vancomycin
red man syndrome (GIVE SLOWLY IV)
ototoxicity - auditoray portion of VIII cranial nerve
nephrotoxicity - interstitial nephritis short term
mechanism of action of dornase alpha
endonucleatic cleavage of extracellular DNA and reduces sputum viscosity (used in CF)
mechanism of action of WARFARIN
vitamin K antagonist and reduces factors 2, 7, 9 , 10 and protein C and S
mechanism of action of ondansetron
selective 5-HT3 (serotonin) receptor antagonist