drug names (L1-3)

Question 1

Phenoxymethylpenicillin (pen V)

Answer 1

Adsorbed by food, reduces bioavailability
therefore take on an empty stomach
(sticks to food, so is not absorbed and has a reduced bioavailability)

Question 2

Tetracyclines

Chelate

Answer 2

metals so absorption reduced by
milk, antacids and iron preparations (will bind to metals so it’s more difficult to be absorbed. it will bind the calcium in milk, become charged, no absorption)

Question 3

Aspirin (NSAIDS)

Answer 3

Irritate the stomach: dyspepsia, nausea
vomiting, diarrhoea
1 in 5 chronic users will have gastric damage

Question 4

names of drugs taken via transdermal route of administration

Answer 4

Nicotine patches
HRT (oestrogen/progesterone)
Fentanyl (opioid analgesic) patches (last 72 hours)
Ibuprofen gel

Question 5

names of drugs taken via intranasal route of administration

Answer 5

GTN (angina)
Desmopressin (diabetes insipidus, nocturnal enuresis). it is a peptide that is broken down orally or taken as a nasal spray

Question 6

names of drugs taken via rectal route of administration

Answer 6

Diazepam rectal tubes (status epilepticus)
Diclofenac suppositories (pain and inflammation)

Question 7

heparin (compartment, volume, characteristics)

Answer 7

plasma, 0.05L/kg

the heparin is an anticoagulant because it is a massive molecule made out of sugar. it has the volume of distribution but it doesn’t move out of the plasma.

Question 8

theophylline (compartment, volume, characteristics)

Answer 8

extracellular, 0.2L/kg

can diffuse out of the bloodstream but it’s isn’t highly lipid-soluble so it stays in the extracellular space so it has a distribution of 0.2 l per kilo

Question 9

ethanol (compartment, volume, characteristics)

Answer 9

total body water, 0.55L/kg (like phenytoin, paracetamol, GTN)
can distribute around the whole body

Question 10

anaesthetics (compartment, volume, characteristics)

Answer 10

partition in body fat
tricyclic
binding to anaesthetic means that the recovery is slow because the anaesthetic distribute into the fat where there is not a lot of blood supply

Question 11

antidepressants (compartment, volume, characteristics)

Answer 11

bind to extravascular tissues outside the blodd vessels

Question 12

P-glycoprotein (Pgp)

Answer 12

it’s an active drug efflux pump in endothelial cells of the BBB

Question 13

warfarin

Answer 13

(anti-coagulant)

low lipid solubility and low tissue binding
Volume of distribution 0.14 l/kg

Question 14

amitriptyline

Answer 14

(anti-depressant)

High lipid solubility + tissue binding
Volume of distribution 15 l/kg

Question 15

agonists (2 eg) and their clinical use

Answer 15

• Adrenaline (heart: increase rate and force of contraction)
  also anaphylactic shock
• Salbutamol (asthma)
• Oxymetazoline (nasal congestion)
• Dopamine (heart, increase rate and force of contraction)
• Morphine (analgesic for severe pain)
  (opiate receptor agonist)

Question 16

Clinical use of partial agonists

Answer 16

example - buprenorphine
In theory, a partial agonist would reduce over-activity, but won’t block basal activity

Buprenorphine (Temgesic)
Less abuse liability, less dysphoria
Used as a painkiller, subligual

Also: buspirone, aripiprazole, norclozapine,
acebutolol, penbutolol & pindolol

Question 17

alpha bungarotoxin

Answer 17

it is an irreversible antagonist
alpha bungarotoxin is a snake venom toxin. it is an irreversible blocker of nicotinic receptors that blocks the neuromuscular junctions competitively and paralyze an animal irreversibly