1. Pharmacology For The Physical Therapy Clinician Basic Principles

2. l Pharmacology can be broadly defined as the science dealing with interactions between living systems and molecules

3. l Throughout the ages, drugs have been produced using natural plant and animal products by native people. This practice has been part of every culture and society in every corner of the world.

4. Some Examples……. l Hollyhock Tea - made from the leaf and root of the Hollyhock plant. l Used For : sore throats, duodenal ulcers, GI tract infections

6. l Echinacea - the roots, seed heads & petals can be used to make an Echinacea tincture and salve l Uses : stimulates immune defense, speeds healing, limits edema & swelling.

8. l Jojoba - the beans and the leaves are used to make a variety of oil, soap & shampoo products. l Uses : Soaps, shampoos, oil lubricants - often used for a remedy for asthma, dandruff, and as an anti-inflammatory

10. Advantages Of Synthetic Drugs l Improved purity l Improved action due to an altered chemical structure l Longer biological half-life l Improved fat solubility

11. l Greater drug concentration l Longer shelf life l Preserve the environment l Less costly to produce

12. Drug Interactions With A Biological System l Pharmacodynamic Interactions l Pharmacokinetic Interactions

13. l Pharmacodyamic Interactions The mechanism of action - the the drug works on the body

14. l Pharmacokinetic Interactions The way in which the body absorbs, distributes and eliminates the drug

15. Drug Nomenclature l Chemical Name The chemical name describes the chemical structure of a drug. Used by pharmacists & researchers all over the world

16. Examples……. l Tylenol (Acetaminophen) N-acetyl-para-aminophenol

17. l Phenobarbitol 5,5-phenylethylbarbituric acid

18. l Generic Name It is generally derived from the chemical name but is shorter It is also known as the official or non-proprietary name

19. Examples……. l Dextromethorphan Dextromethorphan is the generic name for the drug with the chemical name of : d-3-methoxy-N-methylmorphinan

20. l Dantrolene Sodium Dantrolene is the generic name for the drug with the chemical name of : 1-[[[5-(4-nitrophenol)-2- furanyl]methylene]amino]-2-4- imidazolidinedione

21. l Trade Name This is the name the manufacturer gives to the drug that distinguishes it from the same drug made by other drug companies

22. Examples……. l Flecanide Acetate is the generic name for a drug with the trade name of : Tambocor

23. l Digoxin is the generic name for the drug with the trade name of : Lanoxin

24. l Bepridil HCl is the generic name for a drug with the trade name of : Vascor

25. l The FDA catalogs the drug by its generic name l The manufacturer catalogs the drug by its trade name l The research pharmaceutical chemists know the drug by its chemical name

26. Routes of Administration l Enteral Routes l Parenteral Routes

27. Enteral Routes l Drugs that are administered through the alimentary canal via the sublingual, oral or rectal routes

28. Advantages Of The Enteral Route l It is not invasive l Ease of drug administration l The mouth and the GI tract have a rich blood supply for pancorporeal dispersal of the medication

29. l The enteral route avoids large fluctuations in drug delivery l Patients are familiar with the oral delivery route l The GI tract has a massive surface area for absorption

30. Disadvantages of the Enteral Route l Drugs must be lipid soluble l Drugs can be irritating to the mucosa of the mouth and the gut

31. l First Pass Effect l The presence of diseases like Crohn’s Disease is a problem l pH of the GI tract

32. Parenteral Routes l Drugs administered through non- alimentary pathways such as : inhalation, intravenous, intra- arterial, subcutaneous, intramuscular, intrathecal, ocular, topical, and transdermal

33. Advantages of Parenteral Routes l Fast delivery of the medications (IV, inhalation, and intra-arterial routes) l Efficient maintenance of therapeutic ranges (IV and intra-arterial routes)

34. l Ease of self administration (topical, inhalation, rectal, & subcutaneous routes) l Can give large quantities of medication (IV, intra-arterial)

35. First Pass Effect l When an enterally administered drug passes for the first time from the gut into the hepatic portal system and enters the liver, it can undergo First Pass Effect

36. l During First Pass Effect, a certain percentage of the drug is changed from the original mother compound into some intermediate metabolite. All of the drug then passes out into the systemic circulation as 1) the intact drug plus its 2) changed intermediates.

37. l For some drugs, like sublingual nitroglycerin, if it were swallowed, it would be totally inactivated by the liver. So, its first pass effect is complete or 100%

38. l For other drugs that are not as easily cleaved, the First Pass Effect might only be 10%. This means that 90% of the mother compound enters the systemic circulation with only 10% that has been changed into an intermediate.

39. l The intermediate compounds after First Pass Effect may be biologically inactive or they might be extremely active in the body. Many cancer drugs are designed to have intermediates that are just as biologically active against the tumor as the mother compound.

40. l Some medications are designed to be inactive in the pill form. Once these medications pass into the liver (First Pass Effect) they are cleaved into their biologically active intermediate forms. In the pill form, these drugs are called Pre-Drugs.

41. Bioavailability l Bioavailability is defined as the amount of drug that actually makes it to the intended downstream target. Bioavailability is influenced by a number of factors.

42. Factors Influencing Bioavailability l First Pass Effect l Route of administration l Lipid solubility of the drug l Blood flow at the administration site

43. l Blood flow at the intended target organ or site l Absorptivity of the gut l How easily the drug is changed or metabolized

44. Drug Elimination l The liver and the kidneys are the major detoxification organs in the body l The blood, muscles and the lungs are secondary areas where detoxification occurs

45. Biotransformation l The body detoxifies itself through inducing chemical changes in the drugs that have been ingested l The body biochemically alters the drugs through biochemical processes like hydrolysis, oxidation, reduction, conjugation

46. Enzyme Induction l Long term use of medications stimulates enzymatic pathways in the body to more vigorously breakdown the medication into intermediates that can be easily excreted in the feces or urine

47. l There are many stimuli that cause enzyme induction to be turned on such as : l tobacco use l alcohol use l drug abuse l environmental wastes and toxins

48. Why Do Humans Respond Differently To Medications ? l Genetic Factors l Diet, Age, & Adiposity l Alcohol & Tobacco Use l Disease State