1. introduction to pharmacology

2. Drug Any chemical that affects the physiological processes of a living organism

3. . Pharmacology The study or science of drugs

4. History of Drugs In Primitive times –Herbal Remedies –Arrow Poisons –Mood altering foods Opium Cocoa Were used. These were derived from roots, bark,leaves and berries

5. History of Drugs (cont.) 17 th and 18 th Century –Increased knowledge of drugs and shared with world as increase in world travel continued –Widely accepted by physicians and lay persons

6. History of Drugs (cont.) 19 th Century –The beginning of the modern science of pharmacology –Problems Recognized Dose – effect relationship Processes involved in absorption/excretion Localization of the site of action of a drug Specific mechanisms of drug action Relation between chemical makeup & biologic activity of substances

7. History of Drugs (cont.) Developed –Anesthetics –Injection technique –Antipyretics (Aspirin)

8. History of Drugs (cont.) Modern Medicine –Complex science – Big business –Virtually every body function can be enhanced, suppressed, or manipulated by chemical means –Problem with drug abuse worldwide We need to use this new technology wisely; without poisoning ourselves and environment

9. . Drug Names Chemical name Describes the drug’s chemical composition and molecular structure Generic name (nonproprietary name) Name given by the United States Adopted Name Council Trade name (proprietary name) The drug has a registered trademark; use of the name restricted by the drug’s patent owner (usually the manufacturer)

10. Drug Names (cont'd) Chemical name (+/-)-2-(p-isobutylphenyl) propionic acid Generic name ibuprofen Trade name brufen®

11. Drug Classification By chemistry –electrolytes By mechanism –Beta blockers –benzodiazepines By disease –antihypertensives –Antiemetics

12. Components of a Drug Profile Names Classification Mechanism of Action Pharmacokinetics pharmacodynamics Indications Contraindications Side Effects Interactions Routes of Administration Dosage

13. activity In groups of 5 -list 5 properties you expect a ‘good’ drug to have

14. Properties of an Ideal Drug Effectiveness –A drug that elicits the response it was meant to. Safety –Pharmakon= poison in Greek –Safe even at high concentrations and for long periods of administration Reduced by proper administration (iv, ip, im, sc, etc…) No habit forming aspects No side effects ( excessive dosage of opioid analgesics carries a risk of respiratory failure, cancer drugs increase infections, aspirin causes gastric ulcer etc…)

15. Properties of Ideal Drug Selectivity: –One that elicits only the response for which it is given –Selective for specific reaction with no side effects Drowsiness can be caused by antihistamines Constipation, urinary hesitance, and respiratory depression can be caused by morphine

16. Properties of an Ideal Drug Reversible action –Effects be reversible, i.e., removal/subside within specific time –Example: Contraceptives, which are used in family planning should have the property that fertility should be restored soon once the contraceptive is stopped Ease of Administration –Number of doses should be low and easy to administer A drug to be taken every 3 hourly is difficult to administer Insulin for diabetic patients should be given as SC injections.It is not a pleasant experience

17. Additional Properties of Ideal Drug (Continued) less drug interactions –Should not augment or decrease action of other drugs or have adverse combined effects Respiratory depression caused by diazepam (valium), which is normally minimal, can greatly be intensified by alcohol. Low Cost –Easy to afford (especially with chronic illness) Growth hormone costs between abot Rs. 100000/= per month Lifelong medication: hypertension, arthritis, diabetes

18. Additional Properties of Ideal Drug (Continued) Chemical Stability –Not losing of effectiveness with storage

19. Because No Drug is Ideal…….. Because no drug is ideal……. –No drug is safe –All drugs produce side effects –Drug responses may be difficult to predict –Drugs may be expensive –Drugs may be hard to administer All members of health care team must exercise care to promote therapeutic effects and minimize drug induced harm

20. Pharmacologic Principles Pharmaceutics Pharmacokinetics Pharmacodynamics Pharmacotherapeutics Pharmacognosy

21. Pharmaceutics The study of how various drug forms influence pharmacokinetic and pharmacodynamic activities

22. Figure 2-1 The chemical, generic, and trade names for the common analgesic ibuprofen are listed next to the chemical structure of the drug.

23. . Pharmacokinetics The study of what the body does to the drug –Absorption –Distribution –Metabolism –Excretion

24. Pharmacognosy The study of natural (plant and animal) drug sources Natural sources of drugs: –Plants: Alkaloids >>Morphine –Microbes: Antibiotics >> Penicillin, streptomycin –Animal tissues: Hormones>> growth hormone –Minerals: Lithium (Psychotherapy)

25. Pharmacodynamics The study of what the drug does to the body –The mechanism of drug actions in living tissues

26. Pharmacodynamics: Mechanisms of Action Receptor interaction Enzyme interaction other

27. Mosby items and derived items © 2005, 2002 by Mosby, Inc. Drugs act by forming a chemical bond with specific receptor sites, similar to a key and lock. B, The better the “fit,” the better the response. Those with complete attachment and response are called agonists. C, Drugs that attach but do not elicit a response are called antagonists. D, Drugs that attach, elicit a small response, and also block other responses are called partial agonists or agonist-antagonists.

28. Pharmacotherapeutics The use of drugs and the clinical indications for drugs to prevent and treat diseases

29. . Pharmacotherapeutics: Types of Therapies Acute therapy causal therapy Maintenance therapy Supplemental therapy Palliative therapy Supportive therapy Prophylactic therapy Empiric therapy

30. Causal treatment treatment directed against the cause of a disease. conservative treatment that designed to avoid radical medical therapeutic measures or operative procedures. expectant treatment treatment directed toward relief of unpleasant symptoms, leaving cure of the disease to natural forces.

31. palliative treatment treatment designed to relieve pain and distress with no attempt to cure. preventive treatment, prophylactic treatment that in which the aim is to prevent the occurrence of the disease; prophylaxis.

32. Active therapy Short-term medical treatment, usually in a hospital, for patients having an acute illness or injury or recovering from surgery. directed immediately to the cure of the disease or injury.

33. Maintenance therapy Treatment given to sustain level of disease control Ex-asthmatic patients are put on long term steroid inhalers to maintain disease control and prevent acute attacks

34. Palliative therapy Treating a disease which is unable to cure with drugs to comfort the patient and give symptomatic relief Ex-morphine for terminal cancer patients

35. Supportive therapy Any form of treatment intended to relieve symptoms or help the patient live with them rather than attempt changes in the disease course Ex-taking paracetamol for a pneumonia will comfort as the fever and pain will go down, but disease will not be cured

36. empiric treatment treatment by means which experience has proved to be beneficial.

37. Prophylactic therapy Administration of a drug in the absence of known disease, to reduce the occurrence of the disease Ex- antibiotics given after surgery to prevent post op infections

38. Monitoring The effectiveness of the drug therapy must be evaluated One must be familiar with the drug’s: –Intended therapeutic action (beneficial) –Unintended but potential side effects (predictable, adverse reactions)

39. Monitoring (cont'd) Therapeutic index Drug concentration Patient’s condition Tolerance and dependence Interactions Side effects/adverse drug effects

40. . Monitoring (cont'd) Tolerance – A decreasing response to repetitive drug doses

41. Monitoring (cont'd) Dependence – A physiologic or psychological need for a drug

42. Monitoring (cont'd) Interactions may occur with other drugs or food Drug interactions: the alteration of action of a drug by: –Other prescribed drugs –Over-the-counter medications –Herbal therapies

43. Monitoring (cont'd) Medication misadventures –Adverse drug events –Medication errors

44. Other Drug-Related Effects Teratogenic Mutagenic Carcinogenic

45. Toxicology The study of poisons and unwanted responses to therapeutic agents

46. Questions…

47. Thank you…