Metabolism/Pharmacogenetics

Question 1

Buccal

Answer 1

Strengths; avoid first pass, rapid absorption, drug stability.
Weaknesses; inconvenient, advantages lost if swallowed, small dose limit.

Question 2

Sublingual

Answer 2

Strengths; economical, quick termination, avoid first pass, quick absorption.
Weaknesses; unpalatable/bitter drugs, irritates oral mucosa, can’t give large quantities, few drugs absorbed.

Question 3

Rectal

Answer 3

Strengths; children, little/no first pass, vomiting patient, unconscious patient, high concentrations achieved.
Weaknesses; Inconvenient, slow/erratic absorption, irritation and inflammation of rectal mucosa.

Question 4

Solutions/suspensions

Answer 4

Strengths; fastest rate of absorption, easier dosage adjustment, children, those who can’t swallow, feeding tubes.
Weaknesses; loss of potency quickly, bitter taste/odour, preservatives required, potential dosing inaccuracy, inconvenient.

Question 5

Tablets

Answer 5

Strengths; ease of packaging/storage, little taste/smell, accurate dosing.
Weaknesses; slower onset of action

Question 6

Enteric coated

Answer 6

Strengths; mask unpleasant odour, protects from stomach contents, dissolve in intestine.
Weaknesses; can’t be chewed, broken or crushed.

Question 7

Sustained release

Answer 7

Strengths; reduces frequency of dosing.

Question 8

Inhaled

Answer 8

E.g. beta 2 agonists like salbutamol and steroids. Local delivery achieves rapid therapeutic effect for a very low dose so side effects are minimised

Question 9

Topical

Answer 9

E.g. azoles for fungal nail infection or athletes foot. Direct action and no systemic effects so limits side effects.

Question 10

IV

Answer 10

E.g. antibiotics. Rapid onset of action and allows for careful control of drug concentration.