Clinical Pharmacologyfor MRCP 1Andrew Webb

Topics

Clinical Pharmacology:• The principles behind the prescribing process

Therapeutics:• The process of Medical treatment

Main Topic

Pharmacokinetics&

Pharmacodynamics

Interaction

Adverse effects and toxicology

Specific situation/ susceptibility

• Individual drugs: classic & new• Basic science & Mechanisms of action• Clinical trails

Pharmacokinetics

“What the body does to drugs”• Absorption • Distribution• Metabolism• Excretion

PK: Absorption

• GI motility:– Migraine s absn of paracetamol

• Malabsorbtive states:– Coeliac s absn digoxin• But absn propranolol

• Food: milk chelates tetracycline

Interactions!

Precipitant Object

May be two-way

Precipitant Object

PK interaction: absorption

• GI motility– Opioids/antimuscarinic TCADs – Metoclopromide

• Absn

– Cholestyramine – digoxin, warfarin (anionic)• Chelation– By antacids (Al, Mg, Ca) of pred, iron + tetracylines,

• Gut flora – – Antibiotic vit. K synthesis potentiate warfarin

A 65-year-old was advised to start oral digoxin at a dose of 205 µg

daily. His physician explained that the full effect of this treatment

would not be apparent for at least a week.

Which one of the following pharmacokinetic variables did the

physician use to give this explanation?

Which one of the following pharmacokinetic variables did the physician use to give this explanation?

• Bioavailability

• Half-life

• Plasma protein binding

• Renal clearance

• Volume of distribution