copyright © 2007 by saunders, inc., an imprint of elsevier inc. principles of pharmacology chapter...
Post on 26-Dec-2015
235 Views
Preview:
TRANSCRIPT
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc.
Principles of Pharmacology
Chapter 32
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 2
Clinical Pharmacology
Study of the biologic effects of a drug on a patient and the actions of the drug over time
Medical assistants must understand:– Drug action
– Typical side effects
– Route of administration
– Recommended dose
– Individual patient factors that can alter the drug’s effect and elimination
Be prepared to provide safe drug therapy patient education.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 3
Government Regulation
Several federal agencies regulate drugs in the United States.
FDA regulates development and sale of prescription drugs and OTCs.
– New drugs must gain FDA approval before release.
– Drug must pass tests starting in the laboratory on animals and then in human clinical trials.
– Drug must have acceptable benefit-to-risk ratio.
– Copyright awarded to pharmaceutical company for 17 years.
– FDA ensures generic brands are effective and safe.
DEA enforces federal laws designed to control drug abuse and also educates the public on drug-abuse prevention.
FTC regulates OTC advertisement.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 4
Controlled Substances Act (CSA)
DEA enforces CSA regulations.
Drug that has potential for illegal use and abuse must be placed on controlled substance list.
Any new medication that has similar action to drug already on controlled list is automatically considered a controlled substance.
CSA divides controlled substances into five sections according to drug addictive abilities and potential for abuse.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 5
Classification of Controlled Substances
Schedule I—No accepted medical use; illegal to possess. Examples: heroin, LSD, Quaalude, amphetamines.
Schedule II—Severe restrictions; high potential for abuse. Examples: morphine, cocaine, cannabis, Percodan.
Schedule III—Accepted use; moderate to low physical and high psychologic dependence. Examples: Tylenol with codeine, paregoric, anabolic steroids.
Schedule IV—Accepted for use; low potential for abuse. Examples: Librium, Valium, Darvon, Tranxene, Xanax.
Schedule V—Accepted for use; low potential for abuse; drug mixtures that contain limited amounts of narcotics.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 6
Regulations for Management of Controlled Substances
Physician Controlled Substance Registration Certificate– DEA registration number must be included on all
prescriptions for controlled substances.– Renewable every 3 years and specific to site of practice.
Documentation– Number of doses dispensed and administered. – Count of doses on site before and after medication
dispensed.– Specific forms developed for this purpose.– Any discrepancy in drug count must be cosigned.
Record keeping
– Records maintained on purchase and use.– Kept separate from patient chart for 2 years.– Be readily available for DEA inspection.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 7
Controlled Substance Regulations (cont’d)
Controlled substance disposal– Drug loss must be reported to DEA immediately.
– Drug disposal requires two employees to witness and document procedure (Critical Application p. 570).
– Contact DEA for guidelines on disposal of large amount.
Storage
– Immovable locked cabinet.
– Limited access to keys.
*MA must be aware of specific state regulations.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 8
Controlled Substance Prescriptions Must be written in ink or typed.
Prescription must include name and address of patient; physician information including DEA number; amount prescribed, written out, and usually for small quantities; must be manually signed by the physician.
Orders for Schedule II drugs cannot be phoned in except in an absolute emergency, and written prescription must be delivered to pharmacy within 72 hr. Prescription cannot be refilled.
Schedule III, IV, and V drugs may be prescribed by phone or written and refilled up to five times in a 6-month period.
In some states Schedule V drugs can be dispensed by the pharmacist without a physician prescription.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 9
Drug Abuse
Patients may misuse or abuse prescription, OTC, and illegal drugs.
Drug dependence—inability to function unless under the influence of the substance. Can have acute and chronic effects
Physical dependence (addiction)—biochemical changes within the body that require the substance to be used continuously in order for the person to function and to avoid physical discomfort
Psychologic dependence—compulsive craving for the substance
Habituation—mild form (caffeine)
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 10
Prevention of Drug Abuse
Monitor patients who repeatedly call for controlled substance prescription refills.
Request medical records for patients with history of controlled substance use.
Keep prescription pads in safe place.
Store limited amount of controlled substances in office.
Maintain complete and accurate records; keep patient records accurate and complete.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 11
Drug Names
A single drug may have as many as three names: chemical, generic, and trade.
Chemical name is the drug’s formula.
Generic or official name is assigned to the drug and may reflect the chemical name. Is not protected by copyright law.
The trade or brand name is the name given the compound by the developing pharmaceutical company and is protected by copyright for 17 years.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 12
Approaches to Studying Pharmacology
Using drug reference materials is crucial to the safe administration of medications.
Most drug reference books supply the action, indication, contraindications, precautions, adverse reactions, dosage, administration guidelines, and method of packaging.
The most frequently consulted drug reference guide is the PDR, but package inserts also can be used.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 13
Learning about Drugs
Take opportunities to observe the use of drugs in patient care.
Concentrate on the most important drugs in each classification.
Learn about a drug’s primary action and use, then expand your knowledge to its other actions and uses.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 14
Dispensing Drugs: Over-the-Counter Drugs
OTC drugs may interfere or interact with prescription drugs.
Gather information about OTC use at each office visit.
Patient education for safe use of OTCs:– Carefully read label and insert for use guidelines.
– Take only the recommended dose.
– Discard when expired.
– Inform the physician of OTC use.
– Be aware of OTC contraindications.
– Check with pharmacist if you have questions.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 15
Dispensing Drugs: Prescription Drugs
Written order by a physician for the dispensing and administration of a drug for a particular patient.
Must be signed by a physician to be legal.
MA may phone in a prescription to a pharmacy, but the order must first be written down and reviewed by the physician for accuracy.
Phoned order must be documented on the patient chart as a record of the medication.
The MA may write a prescription dictated by the physician, but the physician must review and sign the prescription.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 16
Sample Prescription
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 17
Six Parts of a Prescription
Superscription: Patient's name and address, the date, and the symbol Rx (for the Latin “recipe,” meaning “take”)
Inscription: Main part of the prescription; name of the drug, dosage form, and strength
Subscription: Directions for the pharmacist; size of each dose, amount to be dispensed, and the form of the drug such as tablets or capsules
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 18
Six Parts of a Prescription (cont’d)
Signature: Directions for the patient; usually preceded by the symbol Sig: (for the Latin “signa,” meaning “mark”). The physician writes instructions for the label that tell the patient how, when, and in what quantities to use the medication.
Refill information: May be regulated by federal law if drug is a controlled substance; must write number of times refill allowed.
Physician signature: Must include manual signature of physician and DEA number when indicated.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 19
Drug Interactions with the Body: Pharmacokinetics
Study of the movement of drugs throughout the body
Four actions occur when a drug is taken:– Absorption
– Distribution
– Metabolism
– Excretion
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 20
Pharmacokinetic Terms
Absorption: How a drug is absorbed into the body's circulating fluids– May have local or systemic effect
– Rate of absorption depends on route of administration Oral—convenient, safe, relatively inexpensive
Some drugs can be destroyed by GI system Food slows absorption rate and may interfere with action Metabolism in liver may require higher oral dose Drug may require enteric coating to prevent
destruction or GI irritation Some drugs difficult to absorb through the GI mucosa
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 21
Pharmacokinetic Terms (cont’d)
Parenteral—Administration of drugs by injection– Administered directly into the bloodstream (IV) or into
tissues with rich blood supply
– Fastest acting route of administration (IV, IM, SC)
– Rate of absorption increased with massage at site
– Pharmaceutical preparation may prolong absorption (PenG)
Topical and mucous membrane absorption– Local or systemic effects
– Examples: suppositories, nasal sprays, transdermal patches, inhalants
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 22
Pharmacokinetic Terms (cont’d)
Distribution: How a drug is transported from the site of administration
– Drugs attach to plasma proteins and are carried by bloodstream to target tissue
– Blood-brain barrier—functional barrier between brain cells and capillaries
Metabolism: How the drug is inactivated, including the time it takes for a drug to be detoxified and broken down into byproducts– Occurs in the liver for excretion in the kidneys
– Drug tolerance—liver destroys it so rapidly that doses must be increased continuously for same effect
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 23
Pharmacokinetic Terms (cont’d)
Excretion: The route by which a drug is excreted, or eliminated, from the body and the amount of time such a process requires– Primarily eliminated by kidneys, also by exhalation,
milk glands, skin, and so on
– Drug half-life—time required for drug amount to be decreased by 50%
– Half-life used to determine frequency of medication administration to maintain therapeutic blood levels
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 24
Factors That Affect Drug Action
Body weight
Age
Sex
Time of day
Pathologic factors
Immune responses
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 25
Factors That Affect Drug Action (cont’d)
Psychologic factors
Tolerance
Accumulation
Idiosyncrasy
Drug-to-drug interactions– Antagonism—action of one drug decreases intensity
or shortens duration of action of another drug
– Synergism—a drug increases or prolongs action of another drug
– Potentiation—two differently acting drugs increase each other’s effects
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 26
Classifications of Drug Actions
Drugs are generally classified according to their actions on the body or according to the body system they affect.
May have multiple actions and therefore multiple classifications.
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 27
Adrenergic
Action: Constricts blood vessels, narrows the lumen of a vessel
Examples: Epinephrine, phenylephrine (Neo-Synephrine)
Primary use: Stops superficial bleeding, increases and sustains blood pressure, and relieves nasal congestion
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 28
Analgesic
Action: Lessens the sensory function of the brain
Examples: – Nonnarcotic—aspirin; acetaminophen (Tylenol);
ibuprofen (Advil, Motrin)
– Narcotic—meperidine (Demerol); hydrocodone (Vicodin); propoxyphene (Darvon)
Primary use: Pain relief
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 29
Anesthetic
Action: Produces insensibility to pain or the sensation of pain
Examples: Bupivacaine (Marcaine); lidocaine (Xylocaine)
Primary use: Local or general anesthesia
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 30
Antacid
Action: Decreases the acidity in the stomach
Examples: omeprazole (Prilosec); esomeprazole (Nexium); lansoprazole (Prevacid); pantoprazole (Protonix); magaldrate (Riopan); calcium carbonate (Maalox)
Primary use: Treatment of gastric hyperacidity
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 31
Antianxiety
Action: Reduces anxiety and tension
Examples: Chlordiazepoxide (Librium); diazepam (Valium); alprazolam (Xanax)
Primary use: Produces calmness and releases muscle tension
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 32
Antibiotic
Action: Kills or inhibits the growth of microorganisms
Examples: Cefaclor (Ceclor); tetracycline (Acromycin); amoxicillin (Augmentin)
Primary use: Treatment of bacterial invasions and infections
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 33
Anticholinergic
Action: Parasympathetic blocking agent, reduces spasm in smooth muscle
Examples: Scopolamine; atropine sulfate
Primary use: Dry secretions
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 34
Anticoagulant
Action: Delays or blocks the clotting of blood
Examples: Heparin; warfarin sodium (Coumadin)
Primary use: Prevention of blood clots
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 35
Antidepressant
Action: Treats depression
Examples: Fluoxetine (Prozac); imipramine pamoate (Tofranil); amitriptyline (Elavil)
Primary use: Mood elevator
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 36
Antiemetic
Action: Acts on hypothalamus center in the brain
Examples: Prochlorperazine (Compazine); trimethobenzamide (Tigan); metoclopramide (Reglan)
Primary use: Prevents and relieves nausea and vomiting
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 37
Antiepileptic (Anticonvulsant)
Action: Reduces excessive stimulation of the brain
Examples: Phenytoin (Dilantin); phenobarbital; carbamazepine (Tegretol)
Primary use: Epilepsy and other convulsive disorders
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 38
Antifungal
Action: Slows or retards the multiplication of fungi
Examples: Miconazole (Monistat); nystatin (Mycostatin); amphotericin B
Primary use: Treatment of systemic or local fungal infections
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 39
Antihistamine
Action: Counteracts the effects of histamine; may inhibit gastric secretions
Examples: Brompheniramine maleate (Dimetane); chlorpheniramine (Chlor-Trimeton); diphenhydramine (Benadryl); promethazine (Phenergan); cimetidine (Tagamet); ranitidine (Zantac)
Primary use: Relief of allergies; prevention of gastric ulcers
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 40
Antihypertensive
Action: Blocks nerve impulses that constrict arteries; or slows heart rate, decreasing contractility; or restricts the hormone aldosterone in the blood
Examples: Atenolol (Tenormin); doxazosin mesylate (Cardura); metoprolol (Lopressor); methyldopa (Aldomet)
Primary use: Reduces and controls blood pressure
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 41
Antiinflammatory
Action: Antiinflammatory or antirheumatic
Examples: – Nonsteroidal (NSAIDs): ibuprofen (Advil, Motrin);
naproxen (Naprosyn)
– Steroidal: dexamethasone (Decadron); prednisone (Cortisone)
Primary use: Treatment of arthritic and other inflammatory disorders
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 42
Antineoplastic
Action: Inhibits the development of and destroys cancerous cells
Examples: Interferon alfa-2a (Roferon-A); hydroxyurea (Hydrea); cyclophosphamide (Cytoxan); fluorouracil (Adrucil)
Primary use: Cancer chemotherapy
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 43
Antipruritic
Action: Relieve itching
Examples: Calamine lotion; hydrocortisone ointment; Benadryl
Primary use: Allergies or topical exposures that cause itching
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 44
Antipyretic
Action: Reduces body temperature
Examples: Aspirin, acetaminophen, ibuprofen
Primary use: Reduces fever
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 45
Antispasmodic
Action: Relieves or prevents spasms from musculoskeletal injury or inflammation
Examples: Methocarbamol (Robaxin); carisoprodol (Soma)
Primary use: Sport injuries
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 46
Antitussive (Cough Suppressant)
Action: Inhibits the cough center
Examples: – Narcotic: Codeine sulfate
– Nonnarcotic: Dextromethorphan (Romilar, Robitussin DM)
Primary use: Temporarily suppresses a nonproductive cough; reduces the thickness of secretions
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 47
Bronchodilator
Action: Relaxes the smooth muscle of the bronchi
Examples: Aminophylline (Aminophyllin); theophylline (Theo-Dur); epinephrine (Adrenalin, Sus-Phrine); albuterol (Ventolin, Proventil); isoproterenol (Isuprel)
Primary use: Treatment of asthma, bronchospasm; promotes bronchodilation
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 48
Cathartic (Laxative)
Action: Increases peristaltic activity of the large intestine
Examples: Magnesium hydroxide (milk of magnesia); bisacodyl (Dulcolax); casanthranol (Peri-Colace); psyllium hydrophilic muciloid (Metamucil)
Primary use: Increases and hastens bowel evacuation (defecation)
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 49
Contraceptive
Action: Inhibits conception
Examples: Medroxyprogesterone acetate (Depo-Provera); norgestrel (Ovrett); ethinyl estradiol and ethynodiol diacetate (Demulen 1/35)
Primary use: Family planning
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 50
Decongestant
Action: Relieves local congestion in the tissues
Examples: Ephedrine or phenylephrine (Neo-Synephrine); pseudoephedrine (Sudafed); oxymetazoline (Afrin)
Primary use: Relief of nasal and sinus congestion caused by common cold, hay fever, or upper respiratory tract disorders
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 51
Diuretic
Action: Inhibits the reabsorption of sodium and chloride in the kidneys
Examples: Hydrochlorothiazide (Dyazide, Esidrix, HydroDiuril); furosemide (Lasix); triamterene (Dyrenium)
Primary use: Increases urinary output, decreases blood pressure
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 52
Expectorant
Action: Increases secretions and mucus from the bronchial tubes
Examples: Diphenhydramine (Benylin); guaifenesin guaiacolate (Fenesin, Robitussin)
Primary use: Upper respiratory tract congestion
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 53
Hemostatic
Action: Controls bleeding, a blood coagulant
Examples: Phytonadione, vitamin K (Konakion); absorbable hemostatics, such as Gelfoam and Surgicel, are applied directly to a wound
Primary use: Control of acute or chronic blood-clotting disorder; formation of absorbable, artificial clot
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 54
Hematopoietic
Action: Promotes red blood cell production
Examples: Epoetin alfa (Epogen, Procrit)
Primary use: Treatment of anemia in chemotherapy patients
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 55
Hypnotic (Sedative)
Action: Induces sleep and lessens the activity of the brain
Examples: Secobarbital (Seconal); flurazepam (Dalmane); temazepam (Restoril)
Primary use: Insomnia; lower doses sedate
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 56
Hormone Replacement
Action: Replaces hormones or compensates for hormone deficiency
Examples: Insulin (Humulin); levothyroxine sodium (Synthroid); estrogen (Premarin)
Primary use: Maintenance of adequate hormone levels
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 57
Lipid-Lowering
Action: Decreases blood cholesterol levels and/or increases HDL levels
Examples: Atorvastatin calcium (Lipitor); simvastatin (Zocor)
Primary use: Management of high blood cholesterol
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 58
Miotic
Action: Causes the pupil of the eye to constrict
Examples: Carbachol (Isopto Carbachol); isoflurophate (Floropryl); pilocarpine (Isopto Carpine)
Primary use: Counteracts pupil dilation
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 59
Mydriatic (Anticholinergic)
Action: Dilates the pupil of the eye
Examples: Atropine sulfate (Isopto Atropine)
Primary use: Ophthalmologic examinations
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 60
Narcotic
Action: Depresses the central nervous system and causes insensibility or stupor
Examples: – Natural narcotics: opium group (codeine phosphate,
morphine sulfate)
– Synthetic narcotics: meperidine (Demerol), methadone (Dolophine), and propoxyphene hydrochloride (Darvon)
Primary use: Pain relief
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 61
Oral Hypoglycemic
Action: Decreases blood glucose levels by increasing insulin production and/or decreasing target cell resistance to insulin or by delaying glucose absorption
Examples: Metformin hydrochloride (Glucophage); acarbose (Precose); chlorpropamide (Diabinese); glimepiride (Amaryl); glipizide (Glucotrol); glyburide (Micronase)
Primary use: Management of Type 2 diabetes mellitus
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 62
Osteoporosis Treatment
Action: Inhibits bone reabsorption and/or promotes usage of calcium
Examples: Alendronate (Fosamax); calcitonin (Miacalcin nasal spray and Calcimar); dihydrotachysterol; etidronate (Didronel)
Primary use: To promote bone mineral density and reverse the progression of osteoporosis
Copyright © 2007 by Saunders, Inc., an imprint of Elsevier Inc. Slide 63
Patient Education: Interactions
Monitor for pregnancy.
Question drug allergies each office visit.
Observe patient for 20 minutes after drug administration.
Educate patient on possible drug side effects.
Educate patient on dose, time of administration, and drug storage.
Question patient on whether medication is being taken as ordered.
Answer questions or consult the physician.
top related