Chapter 3: Administration of Pharmacologic Agents

Transcription

1 Chapter 3: Administration of Pharmacologic Agents

2 Administration of Pharmacologic Agents This chapter provides an overview of drug prescriptions, dosage forms, immunization and patient rights.

3 Drug Prescriptions A. A prescription is an order written by a physician that specifies the medication to be dispensed by the pharmacist to a patient. 1. The prescription should contain: a. the patient s name, b. the date the prescription is filled, c. an Inscription that includes the drug name, the dosage, and quantity, d. the Signa (sig.), i.e. the directions, and e. the signature and address of the prescribing physician. f. It should also be labeled if a Generic substitution is permitted or not.

4 Drug Prescriptions g. The DEA number of a physician, is required on controlled substance prescriptions, but not on a non-controlled substance prescription.

5 Verifying a Controlled Substance Prescription A. A DEA# consists of two letters and seven digits 1. Example: John Smith, M.D. DEA# AS

6 Verifying a Controlled Substance Prescription B. Here are the STEPS TO VERIFY A DEA NUMBER: Example: AP Step 1: add the first, third, and fifth digits of the DEA number. DEA# AP = 15 Step 2: add the second, fourth, and sixth digits of the DEA number. DEA# AP = 16 Step 3: multiply the result of Step 2 by two. DEA# AP the sum of step 2 is 16 x 2 = 32

7 Verifying a Controlled Substance Prescription C. Step 4: add the result of Step 1 to the result of Step 3. The last digit of this sum must be the same as the last digit of the DEA number. DEA# AP the result of step 1 is 15 + the result of step 2 which is = 47 (The last digit in this sum 7 must match the last digit in the DEA # 7. So in this example, DEA #AP is a correct DEA number for the physician.)

8 Verifying a Controlled Substance Prescription 1. The DEA # consists of two letters with the 2nd letter corresponding to the prescriber s last name. Example: Arthur Palmer, M.D. DEA # AP or Arthur Palmer, M.D. DEA # LP is also correct.

9 Safely Filling a prescription A. When safely filling a prescription, the technician should be familiar with common abbreviations used in prescriptions, and unacceptable abbreviations that were formerly in common use. (Pause and discuss the Verifying a Controlled Substance Handout and assign worksheets.)

10 Safely Filling a prescription B. Common Abbreviations used in filling a prescription (View Table in guide)

11 Safely Filling a prescription C. Unacceptable Abbreviations that were formerly in common use 1. This list of abbreviations are deemed dangerous by the Institute for Safe Medication Practices (ISMP) and should not be used per The Joint Commission (TJC) formerly known as the Joint Commission on Accreditation of Healthcare Organizations (JCAHO) accreditation standards.

12 Five Rights when filling a prescription A. There are five rights (right = the correct way) that are used to remember and avoid medication errors. The potential for a drug misadventure exists whenever practitioners do not adhere to them. 1. Right Patient: Always verify patient s name. 2. Right Drug: Always check medication against original prescription. 3. Right Strength: Always check medication against original prescription (age pediatric / elderly). 4. Right Route: Always check route of administration. 5. Right Time: Always check time of administration.

13 Dosage Forms and Routes of Administration A. Routes and dosage forms are determined by many factors: 1. disease being treated, 2. area of body being treated, 3. chemical composition of drug, and characteristics related to absorption, distribution, metabolism, and elimination.

14 Dosage Forms and Routes of Administration B. There are three routes of administration: 1. (Peroral or PO) aka Oral Routes... administering medication orally is the most economical and convenient way to give medication. a. Examples: Tablets, Capsules, Syrups, Suspensions, Solutions, Elixirs, and Powders.

15 Dosage Forms and Routes of Administration 2. Parenteral Routes... medications injected directly into the tissue of the body that do not pass through the liver before entering the bloodstream, thus avoiding the first pass effect through the liver. a. Benefits: Parenteral routes allow for quick absorption of injected medication into the bloodstream and a rapid effect, especially for the IV route. b. Disadvantages: Pain during administration and the possibility of infection since the skin is punctured. Also, once the medication is injected, there is no way to retrieve it if an error has been made. i. Intrarterial (IA): in the artery ii. Intramuscular (IM): in the muscle

16 Dosage Forms and Routes of Administration iii. Intradermal (ID): just beneath the skin iv. Intravenous (IV): in the vein v. Subcutaneous (SQ): in the tissue beneath the skin vi. Intrathecal/Intraspinal: the spinal column

17 Dosage Forms and Routes of Administration 3. Topical Routes Medications are applied to the surface of the skin or mucous membranes. The desired effect can be local (therapeutic effect at the site of administration), or systemic (therapeutic effect after traveling to site of action through systemic circulation). a. Transdermal on the skin surface b. Intraocular - on the eye c. Intranasal in the nose d. Intrarespiratory - in the lungs e. Vaginal - in the vagina f. Rectal - in the rectum g. Aural in the ear

18 Factors That Influence Drug Action A variety of factors can influence the effects of drugs and may require dosage adjustment. A. Age: Pediatric and elderly patients may require a reduced dose because of their smaller size or the inability of the liver to metabolize the medication adequately. 1. In older adults-decreased renal function, changes in gastrointestinal function, and hepatic insufficiency are physiologic changes that can alter drug response. The deterioration of senses like failing eye sight and loss of hearing may make communicating with older adults more complicated it does not alter drug response.

19 Factors That Influence Drug Action 2. The deterioration of senses like failing eye sight and loss of hearing may make communicating with older adults more complicated it does not alter drug response.

20 Factors That Influence Drug Action B. Not understanding these changes can lead to underestimating/overestimating drug dosages in pediatric patients by: 1. Reevaluate all dosages at regular intervals. Be sure the dosage is appropriate for the child s age. 2. A dose appropriate for a neonate may not be appropriate for a premature infant or toddler. 3. Young s Rule is based on the age of the child regardless of weight. It is a dosage calculation rule that converts adult dosing requirements for children.

21 Factors That Influence Drug Action 4. Conversion Formulas to determine a pediatric dosage: Conversion Tips Round to the nearest hundredth. Remember you are calculating the pediatric dose and that the number of times the medication is taken is not affected. Free online math tutor. Multiplying Fractions Keep in mind that you will not have this tutor available to you on exams; it is best to use it only as a guide. (Review Examples)

22 Factors That Influence Drug Action YOUNG S RULE is based on the age of the child regardless of weight. It is a dosage calculation rule that converts adult dosing requirements into pediatric dosing requirements. Age in years x adult dose = pediatric dose Age + 12 years CLARK S RULE is based on a child s weight. Weight in lbs. X adult dose = pediatric dose 150 lbs.

23 Factors That Influence Drug Action C. Gender... men and women have different hormone amounts, thus metabolizing meds at different rates. D. Race... Asian/Pacific Islanders are more likely to be affected by IgA nephropathy (IgA = type of kidney disease) which makes elimination of a med from the body much more difficult and without this function toxicity may occur.

24 Factors That Influence Drug Action E. Patients with specific diseases may not be able to absorb, metabolize or excrete various medications. 1. Impaired gastrointestinal (GI) function may affect absorption. 2. Impaired liver function may affect metabolism. 3. Impaired kidney function may affect elimination. 4. Inadequate nutritional may also adversely affect the metabolism of drugs.

25 Immunization (a.k.a. vaccination) The process in which the immune system is stimulated to acquire immunity to a specific disease. Two types of immunity: 1. Active Immunity results from having contact with an infectious agent or an inactive part of an infectious agent through a vaccine (antibodies are developed). 2. Passive Immunity is the process of becoming immune to a disease by transferring antibodies from a person or animal previously infected.

26 Immunization (a.k.a. vaccination) B. Immunization Schedule 1. Pharmacists can give immunizations if certified. 2. Once a year, high-risk populations and healthcare professionals should be vaccinated against the influenza virus. (Review Immunization Schedule)

27 Teaching Patients to Manage Their Medications A. The pharmacy technician can play an important role in helping patients learn how to manage medications. 1. The technician can have a positive effect on patient drug therapy by accurately collecting and recording the patient s medication history in the patient s profile. 2. A patient s failure to follow the drug regimen is often the result of a lack of understanding and/or motivation.

28 The auxiliary label provides special administration instructions and precautions such as: A. Auxiliary Labels 1. Dietary Auxiliary Labels 2. Dosing Auxiliary Labels a. To decrease the risk of bacterial resistance, pharmacy technicians should place this auxiliary label on antibiotic prescription bottles.c caution is advised 3. Expiration Auxiliary Labels 4. Generic Auxiliary Label

29 The auxiliary label provides special administration instructions and precautions such as: 5. Directional Auxiliary Labels a. Mixing b. Pregnancy Risk Levels i. A no risk in pregnancy ii. C caution is advised iii. D human or animal studies have identified a definite risk iv. X these drugs are not to be used in pregnancy

30 The auxiliary label provides special administration instructions and precautions such as: 6. Legal Auxiliary Label, a.k.a. Transfer Warning required by law to be on the label of a controlled substance when it is dispensed to a patient. 7. Storage Auxiliary Labels 8. Warning Auxiliary Labels

31 Natural Chemicals that Affect Drug Actions and Responses A. The body produces several chemicals that invariably affect the metabolism of drugs (histamine, prostaglandins, and bradykinin). 1. Histamine is widely distributed in bodily fluids and most organs. The highest concentrations are in the lungs, skin, and stomach. a. The release of histamine is the body s mobilization of a protective mechanism which also produces an allergic response (sneezing, itching, watery eyes, runny nose, burning throat).

32 Natural Chemicals that Affect Drug Actions and Responses b. Histamine acts on two separate and distinct receptors, termed H1 and H2. c. H1 receptors are used to affect the contraction of the smooth muscle of the bronchi and intestine and are antagonized by a drug classified as an antihistamine; these include Benadryl, Tavist and Allegra. d. H2 receptors mediate the action of a histamine on gastric secretion and cardiac acceleration. The antagonist of this histamine reaction include Tagamet, Zantac, Pepcid and Axid.

33 Natural Chemicals that Affect Drug Actions and Responses 2. Prostaglandins a. Prostaglandins produce pharmacologic action in several body systems and metabolic pathways. b. In the Endocrine System prostaglandins cause uterine contractions and relaxation. They may also be responsible for uterine spasms and other smooth muscle activity during menstruation. c. In the Cardiovascular System prostaglandins reduce blood pressure, increase the heart rate, and increase the cardiac output.

34 Natural Chemicals that Affect Drug Actions and Responses d. In the Gastrointestinal (GI) System prostaglandins stimulate gastrointestinal mucosal secretion.

35 Natural Chemicals that Affect Drug Actions and Responses 3. Bradykinin a. Cause contraction of the intestinal, uterine, and bronchial smooth muscle. d. Stimulates sensory nerve endings which control pain.