Pharmacology

Question 1

Define ligand

Question 2

Define receptor

Question 3

Law of mass action

Answer 3

The drug receptor interaction is governed by the concentration of the individual components, and is determined by the rate constant of forward/reverse interactions.

Question 4

CSHT remifentanil

Answer 4

4.5 minutes

Question 5

CSHT propofol

Answer 5

15-45 minutes

Question 6

CSHT alfentanil

Answer 6

50-60 minutes

Question 7

What does CSHT mean

Answer 7

Time taken for drug concentration to halve once an infusion at steady state concentration has ceased.

Question 8

Name the different types of drug mechanisms of action (7)

Answer 8

Receptors, Ion channels, Enzymes, Hormones, Physico-chemical, transport systems, neurotransmitters

Question 9

what are the different types of drug interactions (3 main categories)

Answer 9

Physico chemical W
Pharmacokinetic
Pharmacodynamic

Question 10

What are the 4 types of physicochemical drug interaction

Answer 10

Neutralisation (protamine/heparin), Chelation (roc / suggy), Precipitation (Sux / Thiopentone), adsorption (halothane/rubber)

Question 11

4 types of pharmacokinetic drug interactions and examples

Answer 11

1) Absorption - prokinetics, LA with adrenaline (reduced systemic absorption)
2) Metabolism - enzyme inducers (carbamazepine, phenytoin), inhibitors (cimetidine, omeprazole)
3) Distribution - competition for binding sites (aspirin displaces warfarin for plasma proteins = increased unbound fraction)
4) Elimination - urinary alkalinsation to remove salicylates, opioids/BZD reducing ventilation and reducing inhaled agent elimination.

Question 12

4 types of pharmacodynamic interactions and examples

Answer 12

1) Additive - 1+1=2 - N2O + inhaled anaesthetics
2) Synergism- 1+1 = >2 - Propofol and remifentanil
3) Antagonistic - 1+1 = 0 - Naloxone and morphine
4) Potentiation - amplification of drug effect without effect of its own - probenacid and penicillin (reduces renal clearance), NMBD and magnesium/gentamicin.