Drugs and MoA

Question 1

sodium valporate

Answer 1

inhibits voltage-gated sodium channels which stabilises the neurotransmitters in the brain to stop the seizure.

Question 2

carbamezepine

Answer 2

decreases neuronal excitability or enhances inhibition by altering sodium, potassium or calcium conductance or affecting GABA, glutamate or other neurotransmitters that cause seizure activity.

Question 3

Lamotrigine

Answer 3

inhibits voltage gated sodium channels which stabilises and inhibits presynaptic glutamate.

Question 4

Levetiracetam

Answer 4

modulates the synaptic neurotransmission release via binding to the protein SV2A.

Question 5

Topiramate

Answer 5

increases GABA by inhibiting glutamate activity.

Question 6

Phenytoin

Answer 6

voltage gated sodium channel blocker

Question 7

Gabapentinoids

Answer 7

inhibits calcium release

Question 8

SSRIs(1st) such as Citalopram, fluoxetine, sertraline, paroxetine

Answer 8

selectively inhibit the re-uptake of serotonin (5HT) in the synapse at the serotonin transporters (SERT)

Question 9

SNRIs such as venlafaxine, duloxetine

Answer 9

these drugs target SERT AND NET (norepinephrine transporters) and block the reuptake of serotonin and norepinephrine.

Question 10

TCAs such as Amitriptyline, Clomipramine, Imipramine, Nortriptyline

Answer 10

Also target SERT and NET but also have inhibitory effects on sodium channels in the heart and histamine receptors causing them to be more sedating. The first two listed are more sedating than the second two listed.

Question 11

MAOIs such as phenelzine sulphate, moclobemide, selegiline HCl

Answer 11

target the Monoamine oxidase enzyme that are located within the synapse and are responsible for the degradation of 5HT, DA and NE. By stopping their breakdown, levels of each remain higher.

Question 12

Atypical: Bupropion

Answer 12

weak NE and DA reuptake inhibitor. Mirtazapine – a2 receptor antagonist that increases 5HT and NE transmission. Trazodone – inhibits SERT and blocks postsynaptic 5HT receptors.

Question 13

lithium

Answer 13

still unknown

Question 14

Dopamine precursors such as levodopa preparations like levodopa + carbidopa/benserazide

Answer 14

these directly add more dopamine into the brain. The co-admission stop levodopa from being broken down in the gut and allow it to cross the BBB to be used in the brain.

Question 15

Dopamine agonists such as Ropinirole, Pramipexole, Rotigotine, apomorphine

Answer 15

stimulate the dopamine receptors to cause more dopamine to be released.

Question 16

COMTIs such as Entacapone and Tolcapone

Answer 16

inhibits COMT enzymes which break down dopamine in the brain and levodopa in the periphery

Question 17

All Benzodiazepines -

Answer 17

effect the Chlorine channel which is normally stimulated by GABA.
Benzodiazepines have a binding site between the gamma and alpha subunits. Once bound allosterically, benzodiazepines increase the frequency of the channel opening. Anion channels dampen fear and stress responses so reduces anxiety.

Question 18

Adrenergic B-receptor blockers, Bisoprolol, propranolol

Answer 18

Reduce sympathetic manifestation of the heart by blocking those receptors in the heart which reduces the symptoms expressed from anxiety.

Question 19

Serotonin pathways, Buspirone + antidepressants

Answer 19

Buspirone is a partial 5-HT agonist whilst other antidepressants are listed above.

Question 20

1st generation antipsychotics, Chlorpromazine, Benperidol, Flupentixol –

Answer 20

high affinity to the D2 dopamine receptor. It’s only effective against positive symptoms e.g hallucinations.

Question 21

2nd generation antipsychotics, Aripiprazole, Risperidone, Olanzapine

Answer 21

Low affinity to D2 receptor, they tend to inhibit the 5HT receptor more. They have less extrapyrimidal side effects and target positive and negative symptoms.

Question 22

Hyoscine Hydrobromide

Answer 22

Anticholinergic, relaxes smooth muscles which can help with travel sickness and cramps.

Question 23

Metoclopramide (anti-emetic)

Answer 23

acts directly on gastric smooth muscle which stimulates gastric emptying and also blocks the 5HT receptors.

Question 24

Methoxsalen, Khelling, Photofrin (for Vitiligo, psoriasis, cutaneous t-cell lymphoma, graft-versus-host disease)

Answer 24

all contain the psoralen skeleton, these are used alongside UV therapy to make PUVA. Psoralen intercalates into DNA and once exposed to UV it forms adducts with pyrimidine bases. This adduct can be further excited by a proton to blind again with another thymine forming covalent interstrand crosslinks. All this ultimately stops cell multiplication.

Question 25

Hydrogen peroxide 1% (impetigo)

Answer 25

aspecific biocide which generates free radicals which destroys the cell wall components, killing the bacteria

Question 26

For widespread imeptigo, Fursidic acid, Mupirocin

Answer 26

these two topical antibiotics inhibit the protein synthesis of bacteria, causing a bacteria static effect.

Question 27

For any worse bacterial infection, oral Flucloxacillin or Clarithromycin/Erythromycin

Answer 27

flucloxacillin is a cell wall inhibitor which stops transpeptidase from forming cross links with peptidoglycan in the cell wall. Clarithromycin is a bacterial protein synthesis inhibitor as is erythromycin

Question 28

cutaneous human papilloma virus infection, salicylic acid, cryotherapy

Answer 28

salicylic acid is a keratolytic agent and gradually lyses keratinocytes of the growth and reduces its thickness. Cryotherapy causes thermal injury.

Question 29

Mild to moderate, Benzoyl peroxide

Answer 29

Is converted to benzoic acid radicals and nonspecifically interfere with bacteria present in the skin and reduced sebum around the follicles. It also can cause increased turnover rate of epithelial cells which causes skin peeling.

Question 30

Moderate to severe, Topical adapalene + benzoyl peroxide (plus doxycycline)

Answer 30

adapalene inhibits keratinocyte differentiation via binding to retinoid receptors that modulate transcriptional activity of DNA.

Question 31

Moderate to severe, Azelaic acid (plus doxyxyline)

Answer 31

normalises the keratin process and acts against aerobic and nonaerobic bacteria

Question 32

Peripheral pain targeting, Aspirin, Paracetamol, Ibuprofen/Naproxen/Diclofenac –

Answer 32

All are antipyretic (reduces fever). Inhibition of the COX enzyme stops the conversion of arachidonic acid to prostaglandins and thromboxanes.

Question 33

General pain management, opioids such as morphine, codeine, fentanyl, co-codamol, tramadol –

Answer 33

target and agonise the opioid receptors and activate the reward pathway. Diamorphine is typically given in a syringe

Question 34

Non-opioid

Answer 34

paracetamol/NSAID +- adjuvant

Question 35

weak Opioid

Answer 35

codeine, dihydrocodein, tramadol

Question 36

strong opioid

Answer 36

morphine, oxycodon

Question 37

Loop diuretic, Furosemide/Bumetanide

Answer 37

powerful diuretics that cause 15-25% of Na+ to be excreted. They work by blocking the Na+/k+/2Cl symporter at the end of the ascending limb in the loop of henle.

Question 38

For oedema and high intra ocular pressure: Osmotic agents, Mannitol

Answer 38

an inert solute, mannitol increases osmolality of tubular fluid in the PCT and LH which prevents passive water reabsorption, causing an increased urine output.

Question 39

For oedema and hypertension: Thiazide and thiazide like diuretics, Bendroflumethiazide, Indapamide

Answer 39

these drugs cause 5% of Na+ to be secreted by blocking the Na+/Cl- symporter in the early DCT. This inhibits Na+ reabsorption and Cl- transport.

Question 40

For oedema, hyperaldosteronism and heart failure: Potassium sparing diuretics, Spironolactone, Eplerenone

Answer 40

These drugs are aldosterone receptor antagonists which prevents the insertion of Na+/K+ ATPase pumps and ENaC channels in the DCT and collecting duct.

Question 41

For acute alcoholic liver disease (ADL) and withdrawals, Benzodiazepines, Diazepam, Chlordiazepoxide -

Answer 41

Benzodiazepines have a binding site between the gamma and alpha subunits of GABA receptors. Once bound allosterically, benzodiazepines increase the frequency of the channel opening which is similar to the effects of alcohol.

Question 42

Ascites (Swelling of abdomen), Spironolactone

Answer 42

These drugs are aldosterone receptor antagonists which prevents the insertion of Na+/K+ ATPase pumps and ENaC channels in the DCT and collecting duct.

Question 43

Portal vein hypertension, Propanolol, Carvedilol

Answer 43

Reduce sympathetic manifestation of the heart by blocking those receptors in the heart which reduces the symptoms expressed from anxiety.

Question 44

Varicies, Terlipressin

Answer 44

increases systemic vascular resistance, particularly in the splanchnic ares, resulting in a decrease of portal pressure

Question 45

Encephalopathy, Thiamine, Pabrinex

Answer 45

contains vitamins B1,2,6, nictinamide and vitamin C. Lactulose – used to reduce gut transit time which decreases time available for ammonia to be reabsorbed.

Question 46

Rifamaxin

Answer 46

prevents the build up of toxins in the brain which is caused by liver disease. It modulates the gut microbiota to prevent or help with hepatic encephalopathy.

Question 47

Bleeding, Vitamin K –

Answer 47

Stimulates proteins to promote clotting factors.

Question 48

Spontaneous bacterial peritonitis, co-trimoxazole, ciproflox

Answer 48

Co-trimoxazole is a folic acid inhibitor of bacteria and ciproflox inhibits the replication, transcription, repair and recombination of DNA.

Question 49

For bacterial acute otitis media – Amoxicillin(1st)/clarithromycin/erythromycin

Answer 49

Amoxicillin is a cell wall inhibitor which stops transpeptidase from forming cross links with peptidoglycan in the cell wall. Clarithromycin is a bacterial protein synthesis inhibitor as is erythromycin.

Question 50

glaucoma - Latanoprost, travoprost, bimatoprost

Answer 50

all prostaglandin analogues; they work by enhancing uvescleral outflow of the aqueous humour which decreases intraocular pressure and also increase blood flow to the optic nerve.

Question 51

glaucoma - Batoxolol, Timolol

Answer 51

B2 adrenoceptor antagonists which inhibit the production of aqueous humor by inhibiting Cilia cell that produces it.

Question 52

rhinitis - Antihistamines, Cetrizine, loratadine, azelastine

Answer 52

second generation antihistamines which are reverse agonists of the h1 receptor. These do not cross the BBB as they are less lipid soluble due to them being zwitterions. First generation antihistamines are less used but still have certain clinical properties.

Question 53

chlorphenamine

Answer 53

for allergies

Question 54

Promethazine

Answer 54

sedating properties

Question 55

Cyclizine

Answer 55

vomiting and motion sickness.

Question 56

Adrenergic a1 receptor agonists, Pseudoephidrine, ephedrine

Answer 56

Adrenergic a1 receptor agonists, Pseudoephidrine, ephedrinepossess a mixture of direct and indirect acting agonists. Direct versions bind directly to the adrenergic receptors and cause similar effects to noradrenaline; activating sympathetic nervous system, causing vasodilation and closing smooth muscles cells which stops leakage and congestion whilst indirect either antagonise the reuptake and metabolism of NE or increase the output of NE which has the same outcome

Question 57

For bacterial sore throat – Phenoxymethylpenicillin, clarithromycin/erythromycin

Answer 57

Phenoxymethylpenicillin is a cell wall inhibitor which stops transpeptidase from forming cross links with peptidoglycan in the cell wall. Clarithromycin is a bacterial protein synthesis inhibitor as is erythromycin.

Question 58

For fungal mouth/throat infection – Miconazole oral gel/ Oral fluconazole (severe) –

Answer 58

inhibits the fungal enzyme CYP450 14a-lanosterol demethylase which is responsible for changing the production mechanisms of ergosterol, causing irreversible cell membrane damage that impairs its permeability

Question 59

For Rheumatoid arthritis, Methotrexate, Sulfasalazine

Answer 59

Sulfasalazine is not well understood but possesses anti-inflammatory effects. As for methotrexate, it interferes with DNA synthesis which stops the proliferation of cells