Drug Receptor Intercations And Drug Mechanisms

Question 1

Name the four protein drug targets and give an example of each

Answer 1

Receptors e.g. nAch and nicotine
Ion channels e.g. Calcium channel blockers, lidocaine
Transport systems (selective not specific, against concentration gradient) e.g. Cardiac glycosides and TCAs
Enzymes- inhibitors like neostigmine , false substrates like methyl dopa or pro drugs like the conversions of trichloroethanol into chloral hydrate.

Question 2

Name 4 types of antagonism and give examples of each

Answer 2

1) receptor blockade, so atropine to nicotinic receptors
2) physiological antagonism, e.g. Histamine and NA on BP
3) chemical antagonism e.g. Dimercaprol synthesis of heavy metal complexes
4) pharmacokinetic antagonism e.g. Barbiturates increases the synthesis of microsomal enzymes

Question 3

Name 5 mechanism of drug tolerance and give examples

Answer 3

1) pharmacokinetic- the metabolism of that drug increases, e.g. Alcohol
2) REceptor downregulation e.g. Endocytosis of b adrenoceptors
3) receptor densensitisation e.g. nAch at NMJ
4) exhaustion of mediator stores e.g. Amphetamines
5) physiological adaptation e.g. Homeostatic mechanisms that decrease side effects over time