Summary of Chapter 4 — Transcript

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1. 0:00welcome back to the final portion of
2. 0:03this chapter and in this final portion
3. 0:05we're going to be just reviewing what we
4. 0:08learned and making sure that we're able
5. 0:11to apply that information
6. 0:13as we're learning other medications from
7. 0:16other systems
8. 0:18so we started out the chapter by talking
9. 0:20about pharmacokinetics and the
10. 0:22pharmacokinetics is the absorption the
11. 0:25distribution the metabolism and the
12. 0:28excretion and we use the medication
13. 0:31called Omeprazole as the example and
14. 0:34although I wasn't asking you to memorize
15. 0:37everything about the pharmacokinetic
16. 0:39stuff Omeprazole we learned a lot of
17. 0:41terms and we learned how to understand
18. 0:44when someone was talking about the
19. 0:47pharmacokinetics of any medication so we
20. 0:51can apply that information directly to
21. 0:53when someone else is talking about a
22. 0:56pharmacokinetics
23. 0:58and after that pharmacokinetics review
24. 1:01We investigated a little bit more about
25. 1:04pharmacodynamics and pharmacodynamics is
26. 1:07the mechanisms basically the mechanisms
27. 1:10by which drugs act and we were taking a
28. 1:13look at the enzymatic Inhibitors we said
29. 1:16that the main thing that we were to put
30. 1:19in our mind is to try to figure out
31. 1:21whether the enzymatic inhibitor was a
32. 1:24reversible inhibitor or whether it was
33. 1:26an irreversible inhibitor and then the
34. 1:30reversible Inhibitors we further divided
35. 1:33them into subclasses the most important
36. 1:37of which were the competitive Inhibitors
37. 1:40and the non-competitive inhibitors
38. 1:43the most common type of enzymatic
39. 1:46inhibition involves competitive
40. 1:48inhibition in which the medication binds
41. 1:52to the active site of the enzyme and
42. 1:55prevents the actions of that enzyme
43. 1:58obviously we don't take a large enough
44. 2:01dose of that medication to bind all of
45. 2:04the enzymes so there's still some
46. 2:06activity of the enzyme involved
47. 2:09the medication is simply competing for
48. 2:12the active site and when the medication
49. 2:15is not in the active site but the
50. 2:19substrate is the enzyme is going to be
51. 2:22doing its job
52. 2:25we also looked at a few examples of
53. 2:27irreversible inhibition in that case the
54. 2:30medication or toxin will normally bind
55. 2:33covalently in a very very strong bond at
56. 2:38the active site of the enzyme
57. 2:40that is not always the case but in most
58. 2:43instances it is a covalent bond and in
59. 2:47most instances it is bonding to the
60. 2:50active site of the enzyme
61. 2:53from that explanation you can see that
62. 2:55irreversible inhibition of an enzyme can
63. 2:58be very dangerous and even fatal but
64. 3:01it's also the type of inhibition that's
65. 3:03involved in Omeprazole and other proton
66. 3:06pump inhibitors
67. 3:08that's also the reason that despite the
68. 3:11fact that Omeprazole has a half-life of
69. 3:14just about one and a half hours it has a
70. 3:16duration of action in the body that
71. 3:19lasts up to 72 hours
72. 3:22the reason that proton pump inhibitors
73. 3:24are not associated with life-threatening
74. 3:27effects has to do with the fact that
75. 3:29it's affecting an enzyme that's only
76. 3:32used in two places in the body
77. 3:35we furthered our discussions of
78. 3:37enzymatic Inhibitors by discussing
79. 3:40medications that have drug to drug
80. 3:42reactions because of the fact that they
81. 3:45inadvertently affect an enzyme that
82. 3:48metabolizes other drugs
83. 3:52when you hear something that affects one
84. 3:54of the cytochrome p450 enzymes or one of
85. 3:58the cyp enzymes
86. 4:01it's your cue to find out if the client
87. 4:04is on any other medications and if so
88. 4:07whether that medication is
89. 4:10contraindicated for use with the
90. 4:12medication that affects the liver
91. 4:14enzymes
92. 4:17we also briefly discussed the pregnancy
93. 4:19categories finding that pregnancy
94. 4:21category D or E are potentially so
95. 4:25harmful to the growing fetus that the
96. 4:28woman of child bearing age should be
97. 4:31taken off the medication even if she's
98. 4:33not considering getting pregnant
99. 4:36and meanwhile the pregnancy category a
100. 4:39is the very best category and you should
101. 4:42not expect any adverse effects on the
102. 4:45growing fetus
103. 4:47and finally we discussed the indications
104. 4:50contraindications mechanisms of action
105. 4:52and the side effects of the proton pump
106. 4:55inhibitors
107. 4:57but we also use that section to
108. 4:59emphasize that no matter how benign the
109. 5:02condition was that prompted the person
110. 5:04to be prescribed a medication we should
111. 5:08not just suggest to the client that they
112. 5:11go off that medication without first
113. 5:13getting all the details
114. 5:15for instance the person who is on proton
115. 5:18pump inhibitors may say that they're on
116. 5:21them because of gastroesophageal reflux
117. 5:24disease but they really were put on the
118. 5:27medication for a pre-cancerous disease
119. 5:29called Barrett's esophagus and the
120. 5:33person who has Barrett's disease needs
121. 5:36to make sure that there's no acid that's
122. 5:40splashing up into their esophagus
123. 5:42otherwise their condition can progress
124. 5:46to esophageal cancer
125. 5:48so what we have left is just one last
126. 5:51chapter in our understanding medications
127. 5:54course and in that chapter we're going
128. 5:57to look at
129. 5:59neurotransmitters and specifically
130. 6:01neurotransmitters that are involved in
131. 6:04the process of a mesis or vomiting but
132. 6:08that information is going to be able to
133. 6:11be
134. 6:12applied to any of the medications that
135. 6:16affect neurotransmitters
136. 6:18so this is a really interesting chapter
137. 6:21coming up and I'm really hoping you
138. 6:24enjoy it we'll see you there