bigPharma

Question 1

What are the 0th order elimination drugs?

Answer 1

Phenytoin, aspirin, heparin, ethanol

Question 2

What is the purpose of conjugation of drugs?

Answer 2

Addition of hydroxyl or methyl groups to make drugs more water soluble to be excreted. Lipophilic -> hydrophilic

Question 3

Describe the phases of conjugation.

Answer 3

Phase 1- reduction, oxidation, hydrolysis

Phase 2- methylation, acetylation, glucorindation

Question 4

Describe acetylation

Answer 4

Organic esterification with acetic acid. Removal of molecule by addition of acetyl functional group.

Question 5

Why is there a decreased metabolism of drugs in elderly populations?

Answer 5

They have less acetylation so decreased rate of modification- why you never just increase dose and need to track plasma conc.

Question 6

What is cytochrome P450?

Answer 6

Enzyme which metabolises drugs. If inhibited, drug bioavailability increases, so there are more side effects. Can be turned on or off, affected by the liver.

Question 7

What is the function of adrenoceptors?

Answer 7

Vasoconstriction- why beta blockers act against them.

Question 8

Alpha 1 receptors-

Answer 8

Affect- Cardiovascular, GI tract, genitourinary
When activated- Vasoconstriction, smooth muscle contraction
Cause- Circulatory collapse, nasal congestion

Question 9

Alpha 2 receptors-

Answer 9

Affect- Respiratory tract, ciliated cells

Cause- Aqueous secretion

Question 10

Beta 1 receptors-

Answer 10

Affect- Heart, kidneys
Effect- increase cardiac rate, force, contraction
Cause- cardiac decompensation

Question 11

Beta 2 receptors-

Answer 11

Affect- Lungs, smooth muscle, skeletal muscle
Effect- bronchdialation, relaxation of visceral smooth muscle
Cause when blocked- asthma, anaphylaxis

This is why beta blockers induce asthma as they prevent smooth muscle relaxation. Agonists are used to treat asthma and anaphylaxis.

Question 12

Describe Myasthenia Gravis

Answer 12

Non competitive antagonism-
Disease that acts on the neuromuscular junction.
Autoimmune condition that attacks the NMJ - reduces availability of ACh receptors so even at max binding, can’t reach AP. Less neurotransmitter.
Worsens with increased activity.

Question 13

Describe the effects of a non- depolarising blocker

Answer 13

Competitive antagonist. Prevents ACh binding by occupying the receptors. Less ion channel opening so no transmission.
Can reduce the effects by blocking acetylcholine esterase so there is more ACh to increase agonist action.

Question 14

Describe the effects of a depolarising blocker

Answer 14

Agonist action.
Persistent depolarising at the post synaptic membrane. Continued binding so membrane potential above threshold- cannot reset ion channel so remains refractory. Cannot generate another action potential.

Question 15

DDVP pesticide effects and symptoms

Answer 15

Organophosphate poisoning. Irreversible of ACh- esterase. 
D- diarrhoea 
U- Urination
M- Miosis (constriction of pupil)
B- Bronchospasm
B- Bradychardia
E- Emesis (vomit)
L- Lacrimation
S- Sweating
S- Salivation

Question 16

Describe functions of the first 3 (of 5) muscarinic receptors.

Answer 16

M1- neural- slow EPSP
M2- cardiac
M3- glandular secretion, smooth muscle contraction, vascular relaxation

Question 17

What is used to treat DDVP poisoning?

Answer 17

IV route Atropine.

Competitive muscle inhibitor antagonist- muscarinic receptor antagonist

Question 18

What is the Yellow Card Scheme

Answer 18

ADR reporting system to report further rare or long term effects of new drugs. Reverse black triangle symptom on leaflets of medications list these delayed observation symptoms of ADR

Question 19

What drug is used to reverse Paracetamol overdose?

Answer 19

N-acetylcysteine