MOA and class of ALL case study drugs Flashcards
hydrocortisone, prednisolone, dexamethasone
Corticosteroid: Binds to glucocorticoid receptors – induces changes in gene expression.
Inhibition of prostaglandin synthesis via actions on TF
Prostaglandins are inflammatory mediators.
Structurally similar to cortisol.
they also limit the migration of leukocytes to sites of inflammation
mehotrexate
DMARD - disease modifying anti rheumatic drug- maintenance
Directly inhibit cell proliferation and inhibit wide range of cytokines including interleukins, interferons and TNFalpha -(inflammatory mediators)
- Dihydrofolate reductase inhibitor – this enzyme is used for thymine synthesis which is used to make DNA
- Prevents synthesis of pyrimidine (used for DNA/RNA bases)
BOTH = immune cells cannot produce autoimmune antibodies
Folic acid
Synthetic vit B9 (folate) : Converted into tetrahydrofolic acid (THF).
Undergoes methylation – to be used in DNA/RNA bases.
salbutamol, Formoterol
SABA Increase FEV1
Act on beta 2 adrenoceptors to induce bronchodilation.
Bind to B2AR, activate adenylyl cyclase, atpcAMP, activate protein kinase A, close Ca2+ chanells and open K+(change in membrane potential), inhibition of MLC-phos
= airway relaxation
tiotropium, glycopyrrinium
LAMA
Act on muscarinic receptors – antagonise
Blocks parasympathetic bronchoconstriction by preveting ach binding to M3 receptors which would normally induce inc of calcium and lead to contraction of airwatys. Long acting due to slow receptor dissociation
latanaprost
Selectively stimulates the prostaglandin F2 alpha receptor dereasing intraocular pressure via increasing outflow of aquous humor in eye.
beclometasone
Inhaled corticosteroid Prevent the release of inflammatory mediators from cells and inhibit the activity of inflammatory cells.
risedronate, alendronic acid
bisphosphonate: Decreases the rate of bone resorption (where bone tissue is broken down, allowing minerals such as calcium to enter the bloodstream)
carbosistine
mucolytic: Mops up reactive oxygen species and, therefore, prevents cell death of lung cells, which would be caused by reactive oxygen species activating apoptosis pathways.
A balance of different glycoproteins controls the viscosity of mucus.
clarithromycin
macrolide antibiotic
Targets ribosome. Binds to the 50S unit of the ribosome, preventing amino acid translocation and, therefore, preventing the formation of the peptide chain.
ipartropium
Inhibition of the parasympathetic nervous system to induce bronchodilation.
Non-selective M3 antagonist.
Can also inhibit mucus secretion
adcal D3
Colecalciferol with calcium carbonate
nystatin
Polyene antifungal
Inhibits fungal growth
sulfasalazine
aminosalucylatate. inhibit leukotrienes and prostaglandins by blocking the cyclooxygenase pathway. Anti-inflammatory
co-amoxiclav
Beta lactam antibiotic
Binds to penicillin binding protein found on many bacteria and create a covalent bond, preventing the growth and replication of the bacterium.
The acid increases the effectivity of the amoxicillin present in the drug
Contains 1.Amoxicillin, an antibiotic that belongs to the penicillins 2.Clavulanic acid, which helps the amoxicillin work better by reducing drug resistance.
metronidazole
Enters cell via passive diffusion
Interferes with DNA replication
lansoprazole
PPI Creates disulfide bridge with the proton pump to block it. Stops secretion of gastric acid
loreazepam, diazepam
Benzodiazepine
Used for the short-term management of anxiety
Occupy the binding site of GABAa receptors, causing a conformational change, leading to GABA binding. This causes a greater flow of chloride ions into the neurone leading to hyperpolarisation of the membrane and therefore, inhibition of signalling
infliximab
Monoclonal antibody TNF alpha inhibitor
TNF alpha is a chemical messenger the immune system produces that induces inflammation.
Activated primarily by macrophages
amlodopine
Calcium channel blocker
Calcium influx into heart muscle cells leads to contraction, and calcium influx into vascular smooth muscle leads to vasoconstriction. By blocking the calcium channel, the influx of calcium is limited.
This leads to vasodilation, decreased contraction and overall reduction in heart rate and blood pressure.
Think Calcium = Contraction
used in hypertension to lower BP
bisoprolol, atenolol
- Selectively blocks beta 1 adrenoceptors mainly found in the heart and kidney. Blocking this reduces the adrenaline effect on the heart = causing a slower heart rate and relaxed blood vessels
- Reduced sympathetic drive od adrenaline to the heart – reducing cardiac output
atorvastatin, simvistatin
statins
The enzyme HMG-CoA reductase is involved in the synthesis of cholesterol
Statins inhibit this enzyme to therefore, stop the synthesis of cholesterol and, therefore, reduce plasma cholesterol levels
The reduction of plasma cholesterol leads to the upregulation of LDL (bad cholesterol) receptors in the liver, leading to the uptake of cholesterol from the plasma into the liver, therefore also lowering plasma cholesterol levels
apixaban, edoxaban, rivaroxaban
DOAC - direct oral anti coagulant
Apixaban and rivaroxaban are oral reversible inhibitors of activated factor X.
Clotting factors and thromboplastin activate factor X. Activated factor X converts prothrombin to thrombin. Thrombin converts fibrinogen to fibrin, which, when stable, leads to clotting.
zopiclone
z-drug
Similar to benzodiazepines
They have a short half-life and bind to the benzodiazepine binding site on GABAa receptors:
causing a conformational change, facilitating GABA binding. This causes a greater flow of chloride ions into the neurone leading to hyperpolarisation of the membrane and therefore, inhibition of signalling
GABA promotes relaxation. Low GABA activity is linked to insomnia and sleep disrorders
warfarin
Vitamin K antagonist
Vitamin K is essential for the production of prothrombin and factors VII, IX, X: all essential in the clotting cascade (see apixaban MOA)
Warfarin blocks the enzyme vitamin K reductase preventing it from being used in the production of the clotting factors
cefuroxime, cefalexin
Cephalosporin:
These are synthetic antibiotics similar to penicillins
They contain the beta lactam ring that is responsible for their function
They disrupt cell wall synthesis by creating a covalent bond with the PBP of bacterial cells. This prevents peptidoglycan synthesis by crosslinking therefore having a bacteriocidal effect
phytomenadione
Vitamin K – counteracts action of warfarin in clotting cascade
cyclizine
antihistamine that treats nausea and vomiting
binds to histamine H1 receptors (muscarinic receptor) present in chemotrigger zone - activated = vomiting
antagonist
anticholinergic properties
opioids: morphine, codeine
Binds to mu -opioid receptors in the CNS. Stops stimulation of ach release from presynaptic neurine that would activate muscarinic receptors on the postsynaptic membrane. This prevents the signal from being transmitted and therefore, depression of the pain response = analgesia.
Binding to GPCR (mu-opioid receptor) = GTPGDP = alpha and beta/gamma subunit dissociation = inhibit adenylyl cyclase = less cAMP
Also = promote K+ efflux = membrane hyperpolarisation = Ca2+ influx inhibited = inhibition on NT release = pain relief
naloxone
counteracts opioid action
Competitive inhibitor of Mu-opioid receptor. Antagonises action of opioids. Prevents the activation of the GPCR and membrane hyperpolarisation. Therefore pain response is transmitted and NT is released as normal
lactulose
osmotic laxative
Increases the water content in stools to soften them.
docusate
Softener
Surfactant effect on intestines that softens stools
Increases concentrations of water, sodium, chloride and potassium in intestine.
senna
stimulant
aquaporin 3 inhibitor
enetrs colon and is metabolised. Stimulates GIT activity by irritating it.
its metabolites increase COX2, inc prostoglandins associated with dec aquaporin expression in large intestinal epithelial cells. this decreases water reabsorbtion
penecillins: flucloxacillin, amoxicillin, piperacillin
Beta lactam antibiotic
Binds to penicillin binding protein found on many bacteria and create a covalent bond, preventing the growth and replication of the bacterium
rifampicin
rifamycin: binds to the beta subunit of RNA polymerase and inhibits the enzyme. This prevents RNA synthesis and therefore cells cannot replicate.
Has no activity to mammalian RNA - only attacks bacteria - selectivity
enoxaparin
heparin
irreversible binding to factor X - precents formation of thrombin (clotting factor) from protothrombin
sertraline, fluoxetine
SSRI- selective seretonin reuptake inhibitor
This blocks the reuptake of seretonin (5-HT) at the presynaptic trasnporter
increases seretonins activity
mirtazipine
NASSA (noradrenergic and specific seretoninergic antidepressant)
* Inhibits the central presynaptic alpha 2 adrenoceptor
o Causing an increased release of serotonin and norepinephrine
* Increases central noradrenergic and serotonergic neurotransmission
haloperidol
typical FGA antipsychotic
dopamine D2 antagonist. halts the overproduction of dopamine
dopamine stops the production of prolactin from the pituitary gland so antipsychotics increase prolactin levels (dec dopamine levels)
in patients with psychosis, there is an imbalance of each and dopamine. There is an overproduction of dopamine.
risperidone
dopamine D2, 5-HT2A, alpha1-adrenoceptor, and histamine-1 receptor antagonist.
ramipril, lisinopril, perindopril
ACE inhibitor
block the conversion of angiotensin 1 to angiotensin 2 by inviting the angiotensin converting enzyme (ACE)
angiotensin 2 is related to vasoconstriction, raising blood pressure.
The blockage of its formation leads to marinating vasodilation and keeping blood pressure low.
metoclopramide
anti-emetic
targets D2 (dopamine) and 5HT (seretonin) receptors in the CTZ. it is an antagonist
inhibits the actions on the presynaptic and post synaptic D2 receptors and inhibits the muscarinic 5HT receptors
prevents neurotransmission of nausea signal.
losartan, candesartan, irbesartan
These are angiotensin receptor blockers that prevent the binding of angiotensin 2 to the angiotensin receptor.
The angiotensin receptor when active, stimulates vasoconstriction, increasing blood pressure.
ropinerole
dopamine receptor agonist. specifically D2 and D3
trimethoprim
dihydrofolate reductase inhibitor. Binds reversibly. this reduces the conversion of THF to DHF
DHF is essential for bacterial replication as it is used to synthesise bacterial nucleic acids. it has bactericidal activity.
donepezil
Acetylcholinesterase inhibitor
This enzyme typically breaks down Ach. Donepezil inhibits the enzyme. This enhances Ach transmission and relieves symptoms of dementia.
Ach is a neurotransmitter so prevention of its breakdown = increased neurotransmission
entacapone
This is used to optimise parkinson’s medications during off-periods that mimic the activity of dopamine in the brain.
Entacapone prevents the peripheral breakdown of levodopa, by inhibiting catechol-O-methyltransferase, allowing more levodopa to reach the brain.
domperidone
This delays gastric emptying and stimulates the intestine. This makes It ideal for constipation relief and prevention of nausea and vomiting
it can be used low-dose in Parkinson’s
acts on the D2 AND D3 receptors in CTZ. It acts as an antagonist here
co-beneldopa, co-careledopa
(levodopa)
dopamine receptor agonist. Parkinsons: loss of neurons that produce dopamine, which is an essential chemical messenger in the brain relating to cognitive and motor functions. These levodopa drugs act as synthetic dopamine
