Dr Chris Bax London Metropolitan University Dept. Health & Human Sciences c.bax@londonmet.ac.uk

1. PHARMACOLOGY Dr Chris Bax London Metropolitan University Dept. Health & Human Sciences c.bax@londonmet.ac.uk

2. Learning Objectives:

3. Learning Objectives: • Pharmacological principles and processes

4. Learning Objectives: • Pharmacological principles and processes • Drug bioavailability – how do we ensure that a drug is “available”? E.G: will it be absorbed from the gut? • Pharmacokinetics – what the body does to the drug. A D M E

5. Learning Objectives: • Pharmacological principles and processes • Drug bioavailability – how do we ensure that a drug is “available”? E.G: will it be absorbed from the gut? • Pharmacokinetics – what the body does to the drug. A D M E

6. Learning Objectives: • Pharmacological principles and processes • Drug bioavailability – how do we ensure that a drug is “available”? E.G: will it be absorbed from the gut? • Pharmacokinetics – what the body does to the drug: A D M E

7. Pharmacodynamics – what the drug does to the body (esp. at receptor level; drug receptor interactions) • Benefit:risk ratio – the therapeutic index. • Drug overdose and poisoning. • Drug dependence and abuse • An introduction to the pharmacology of the autonomic nervous system

8. Pharmacodynamics – what the drug does to the body (esp. at receptor level; drug receptor interactions) • the therapeutic index. • Drug overdose and poisoning. • Drug dependence and abuse • An introduction to the pharmacology of the autonomic nervous system

9. Pharmacodynamics – what the drug does to the body (esp. at receptor level; drug receptor interactions) • Benefit:risk ratio – the therapeutic index. • Drug overdose and poisoning. • Drug dependence and abuse • An introduction to the pharmacology of the autonomic nervous system

10. Pharmacodynamics – what the drug does to the body (esp. at receptor level; drug receptor interactions) • Benefit:risk ratio – the therapeutic index. • Drug overdose and poisoning. • Drug dependence and abuse • An introduction to the pharmacology of the autonomic nervous system

11. Pharmacodynamics – what the drug does to the body (esp. at receptor level; drug receptor interactions) • Benefit:risk ratio – the therapeutic index. • Drug overdose and poisoning. • Drug dependence and abuse • An introduction to the pharmacology of the autonomic nervous system

12. Recommended Books • Pharmacology – Rang, Dale Ritter & Flower, 2007. Churchill Livingstone.

13. Pharmacology • – the science of drugs

14. Pharmacology • – the science of drugs • - the interaction of drugs with living tissues

15. Routes of drug administration: 1. Oral

16. Routes of drug administration: 1. Oral • Advantages: convenient

17. Routes of drug administration: 1. Oral • Advantages: convenient • Disadvantages: absorption

18. Routes of drug administration: 1. Oral • Advantages: convenient • Disadvantages: absorption digestion

19. Routes of drug administration: 1. Oral • Advantages: convenient • Disadvantages: absorption digestion compliance

20. Routes of drug administration: 1. Oral • Advantages: convenient • Disadvantages: absorption digestion compliance 1st pass effect

21. 2. Sublingual

22. 2. Sublingual • rapid effect

23. 3. Cutaneous - local - systemic

24. 3. Cutaneous - local - systemic Steady rate of absorption

25. 3. Cutaneous - local - systemic Steady rate of absorption Avoids 1st pass effect

26. 4. Intravenous - bolus - steady infusion

27. 4. Intravenous - bolus - steady infusion - Rapid

28. 4. Intravenous - bolus - steady infusion - Rapid - Avoids problems of absorption

29. 4. Intravenous - bolus - steady infusion - Rapid - Avoids problems of absorption • requires clinical expertise

30. 4. Intravenous - bolus - steady infusion - Rapid - Avoids problems of absorption • requires clinical expertise • E.G. anaesthetics, chemotherapeutic agents

31. 5. Nasal

32. 5. Nasal Convenient Rapid effect

33. 5. Nasal Convenient Rapid effect E.G: ADH, GnRH, calcitonin

34. Intrathecal - into the sub-arachnoid space.

35. Intrathecal - into the sub-arachnoid space. - Requires clinical expertise

36. Intrathecal - into the sub-arachnoid space. - Requires clinical expertise • E.G: anti-cancer drugs, local anaesthetics, antibiotics

37. 7. Rectal. For patients who are: vomiting excessively; in status epilepticus; unconscious.

38. 8. Others….. Eye drops Intramuscular Intraperitoneal

39. A D M E • Absorption:

40. A D M E • Absorption: Stomach plasma tissues

41. Most important factor = lipid solubility

42. Most important factor = lipid solubility • The best absorbed drugs are lipid soluble (hydrophobic; lipophilic),

43. Most important factor = lipid solubility • The best absorbed drugs are lipid soluble (hydrophobic; lipophilic), • …and are not electrically charged.

44. Most important factor = lipid solubility • The best absorbed drugs are lipid soluble (hydrophobic; lipophilic), • …and are not electrically charged. • WHY?

45. However, most drugs are not lipids; most are partly hydrophilic, and partly hydrophobic.

46. However, most drugs are not lipids; most are partly hydrophilic, and partly hydrophobic. • In addition, drugs are often not pH neutral, but are weak acids or weak alkalis.

47. A simple example…. • A weak acid such as acetyl salicylic acid HA likes to give away its H (this is the definition of an acid)

48. HA H+ + A- weak hydrogen base acid ion

49. HA H+ + A- weak hydrogen base acid ion Acetyl salicylic H+ ion Acetyl Salicylate acid

50. HA H+ + A- weak hydrogen base acid ion Acetyl salicylic H+ ion Acetyl salicylate acid Uncharged(charged) charged