Different categories of medicines and their actions. Iain G. Jack 4 th February 2011. Content of today’s lecture. How can we categorise drugs? How do drugs cause their effects? Specific receptors: lock & key Non-specific effects Pharmacokinetics. Introduction. What is a drug?
Iain G. Jack
4th February 2011
Insulin, growth hormone
Most modern medicines
How the body deals with the drug
We need to consider:
Route of Administration
Absorption and distribution
Metabolism and excretion
Route of administration depends on:
Absorption irregular and unpredictable
Less convenient than oral route
Low patient acceptabilityRectal & Vaginal Route
Drugs inhaled through the nose or mouth to produce local or systemic effects
Drug dose required to produce desired effect is much smaller than oral route therefore reduction in side effectsInhalation Route
Binding to plasma proteins: if a drug is bound to large plasma proteins, it will be unable to get out as the proteins are too large.
Arggh! I can’t fit through!
Extent of blood supply.
If a tissue is well perfused with blood,
drugswill get there faster.
Adipose tissue has low blood
perfusion sodrugs reach itslowly.
TimeMetabolism: what happens to a drug