Psychopharmacology by Sue Henderson

1. Psychopharmacology by Sue Henderson

2. Terminology

3. National Health Survey 04-05

6. Decline in hospital stay

8. Key points about drugs: Drugs alter or mimic body functions (but do not create new functions) Drugs have multiple actions (which may or may not be desired). Most psychotropic drugs interact with the body via receptors.

9. Development of a drug 2. “Gee it’s wonderful. It’s simple & cures magically” 1. “Another one of his fool ideas” 4. Used carefully in selected cases it is the best therapy for “X” disease. 3. Death from “X”. “It’s a poison! I wouldn’t give it to a dog!”

10. Pharmacokinetics (Study of movement of drug through the body) • Absorption • Distribution • Metabolism • Elimination

11. Pharmacokinetics (Study of movement of drug through the body) Absorption: The rate at which a drug gets out of the G.I. tract & into the blood stream. Distribution: process of drug molecules leaving the blood stream to reach tissues & organs.

12. Body membranes affecting drug distribution: Capillaries • General body capillaries allow drug molecules to pass freely into the surrounding tissue.

13. Glial cells Capillary wall Blood Brain Barrier BBB • Brain capillaries have a dense walled structure & are surrounded by glial cells (lipid). This prevents many drug molecules from entering the surrounding tissue.

14. Termination of drug action. Metabolism: Detoxification or breakdown. Enzymes (Cytochrome P450) in liver cells transform drug from fat soluble to water soluble. Elimination: removal of drug from body. Most via kidney’s, lungs & G.I. Tract (small amounts)

15. Pharmacodynamics. How drugs act on body Drug receptor interaction: drug concentrated at the site of action. Effect (body responses): Therapeutic effects, intoxication & side effects. The effect will vary depending on age, gender & health of person, plus the route, frequency of use, duration of use and the environment in which the drug is consumed.

16. Mechanism of action • Blockade of receptors • Receptor sensitivity changes • Reuptake inhibition • Interference with storage vesicles • Pre-curser chain interference • Synaptic enzyme inhibition • Second messenger cascade

18. Neurotransmitter Re-uptake pump Receptor Axon Dendrite Synapse Presynaptic storage vesicles Normal neurotransmission Dendrite

19. Agonist = Mimic

20. Agonist = Facilitate binding

21. Blocking = Antagonist

22. Up-regulation

23. Down-regulation

24. Acetylcholine Serotonin GABA Glutamate Dopamine Noradrenaline All 6 major neurotransmitters have been shown to influence each other’s function in the brain.

25. Dopamine Noradrenaline Serotonin = Acetylcholine Normal

26. Acetylcholine Noradrenaline& Serotonin Depression

27. Glutamate, Noradrenaline Dopamine Acetylcholine Mania

28. Dopamine Acetylcholine Schizophrenia

29. Parkinson’s Acetylcholine Dopamine

30. Dopamine Norepinephrine Serotonin Acetylcholine Dementia

31. References • Bryant, B. J., Knights, K. M., & Salerno, E. (2002). Pharmacology for health professionals. Marrickville, N.S.W.: Elsevier Science Harcourt Australia. • Glod, C. A. (1998). Contemporary psychiatric-mental health nursing : the brain-behavior connection. Philadelphia: F.A. Davis.

32. References • Julien, R. M. (2001). A primer of drug action : a concise, non-technical guide to the actions, uses, and side effects of psychoactive drugs. New York: W. H. Freeman and Co. • Salerno, E. (1999). Pharmacology for health professionals. St. Louis: Mosby. • Townsend, M. C. (2000). Psychiatric mental health nursing: Concepts of care. (3rd ed.). Philadelphia: F. A. Davis.

33. References • Whelan, G. (1998). The pharmacological dimensions of psychoactive drugs. In M. Sabto (Ed.), Drug use in Australia: A harm minimisation approach (pp.14-29). Melbourne: Oxford University Press.