Chapter 11 Therapeutic Medications

Question 1

What are pharmokinetics?

Answer 1

Study of the movement of a drug through the body to produce the desired effects

Question 2

How do drugs move in the body?

Answer 2

Administration
Absorption
Distribution
Metabolism
Excretion

Question 3

What are the two drug administration routes?

Answer 3

enteral route
parental route

Question 4

What is the enteral route of drug administration?

Answer 4

GI tract for entry (oral, sublingual, rectal)
Combined with vehicles to facilitate entry (tablets, capsules, liquids, powders)
Enteric-coated preparations – covered by acid-resistant materials, protect drug from acid and pepsin in stomach, dissolves intestine
Sustained-release preparations – capsules or tablets filled with tiny spheres that contain the drug

Question 5

What is the parental route of drug administration?

Answer 5

do not use GI tract to enter, invasive (intravenous) or noninvasive (inhalation, topical)

Question 6

What are the characteristics of drug absorption?

Answer 6

Movement of a drug from its site of administration into the blood
Rate of dissolution, surface area (small intestine or lungs have large surface area), blood flow (high blood flow) and lipid solubility (cross membrane rapidly)
Liquid medication > enteric-coated preparation
Drug to reach target site – cross cell-membrane
Via channels and pores
Transport system that uses natural body chemicals as carriers
Direct penetration – lipid soluble moving from area of high lipid concentration to low lipid concentration

Question 7

What can affect drug distribution?

Answer 7

blood flow
heart, kidneys, liver and brain has greater blood flow than muscles and skin

Question 8

How are drugs distributed to target sites?

Answer 8

capable of exiting the vascular system and entering the cell membrane via a transport system or through lipid solubility

Question 9

Where do most drugs leave the blood?

Answer 9

at the capillary beds
little to no resistance to the drug’s exit

Question 10

What happens to drugs in the blood to the brain?

Answer 10

Brain – drug must pass through the blood brain barrier, must be lipid-soluble, some don’t exit the blood (drugs that bind to protein, especially albumin)

Question 11

What do most drugs need to exert a therapeutic effect?

Answer 11

they need receptors

Question 12

What are the characteristics of drug metabolism?

Answer 12

The enzymatic alteration of the structure of a drug, where the original drug is broken down into metabolites
Most drug metabolism – liver via hepatic enzymes  first-pass effect
Liver  increase/decrease therapeutic action, toxicity of the drug
No mechanisms to break down drug  excreted in urine unchanged

Question 13

What are the characteristics of drug excretion?

Answer 13

Drug removed from body through urine, sweat, bile, saliva, breast milk or lungs
Two types of drug excretion: renal (kidney) and hepatic (liver), most drugs excreted in the urine by the kidneys
Rate of excretion – quantity and frequency of dosage
Reduced kidney function – at risk to toxicity of medication
Ibuprofen – medication excreted by kidneys

Question 14

What is the minimum effective concentration (MEC) in relation to blood plasma levels?

Answer 14

minimum concentration that must be present for the drug to be effective

Question 15

what are toxic concentrations when talking about a drugs blood plasma level?

Answer 15

drug levels in blood plasma that are too high, increase risk of toxic effects

Question 16

What is the therapeutic range?

Answer 16

Range between the MEC and the toxic concentration

Question 17

what is the objective of drug dosing?

Answer 17

maintain plasma levels within the therapeutic range, wider this range = safer the drug

Question 18

True or False. The toxic concentration of acetaminophen range is 30-fold greater than the MEC

Answer 18

true

Question 19

What do you need to do with medications with narrow therapeutic range?

Answer 19

monitor blood levels (asthmatic medication theophylline)

Question 20

What happens to drug concentrations in blood during metabolism?

Answer 20

it rises

Question 21

What happens to drug concentrations in blood during excretion?

Answer 21

it declines

Question 22

How is the absorption of injected drugs?

Answer 22

absorb and enter blood rapidly

Question 23

how long does it take before the onset of effects when drugs are ingested orally?

Answer 23

30 min

Question 24

What is the maximal efficacy?

Answer 24

Dose at which a response occurs and continues to increase in magnitude before reaching a plateau or threshold

Question 25

What happens when a drug response reaches threshold?

Answer 25

Response reaches threshold – increase in response doesn’t continue, even if more medication is given – more of recommended dose of a drug does not produce increased effects = toxicity

Question 26

What is a drug's half-life?

Answer 26

time required for the amount of a drug in the body to reduce by 50% Few minutes to a week Longer the half-life of a drug, slower it leaves the body

Question 27

What is the half-life of acetaminophen?

Answer 27

half-life of 2 hours, every 2 hours = 50% of the acetaminophen in the body is excreted

Question 28

What is the potency of a drug?

Answer 28

more potent drug = lower dosage produces same effects index for the amount of drug that can be administered to elicit a desired response

Question 29

What does drug interactions refer to?

Answer 29

refers to the ability of one drug to alter the effects of another drug May intensify (synergistic action) or reduce (inhibit) the effects of the drug

Question 30

What are drug interactions influenced by?

Answer 30

Genetics and age Current illness or disease Quantity of drug ingested Duration of the drug therapy Time interval between taking two or more drugs Which drug is taken first

Question 31

What are mild adverse drug reactions?

Answer 31

side effects such as drowsiness, nausea, upset stomach Temporary, tolerated for short periods of time Allergic reactions – beta-lactam antibiotics, NSAIDs, sulfonamides

Question 32

What are local adverse drug reactions?

Answer 32

limited to an area

Question 33

what are systemic adverse drug reactions?

Answer 33

heart palpitations, acute bronchospasm

Question 34

what are OTC drugs?

Answer 34

over the counter drugs, purchased by the customer, treat minor problems OTCs have lower strength than their respective prescription counterparts

Question 35

What are the three names that every medication has?

Answer 35

a chemical name (scientific compound) a generic name (drug's official name) a brand name (used by individual manufacturer)

Question 36

What is the drug protocols for using over-the-counter medications?

Answer 36

Identification of the medical condition Screening questions that should be asked to identify the potential for any adverse effects General signs and symptoms of the condition Suggested treatment Suggested OTC medication Banned substance note Approval signature/date of the supervising physician Documentation for rescue inhalers ADHD/ADD documentation from supervising physician on file

Question 37

What are tips for proper use of medications?

Answer 37

Use only as directed Keep medications in the original container, do not alter the label Do not use if the container has been tampered with Do not use the medication if discoloured or in the expiration date has passed Measuring spoons or cups should be used when measuring liquid medication Never share your medication with another person When directed, oral medications should be taken with food If a corticosteroid is injected into a joint, do not stress the joint too soon following the injection because pain will be masked If an overdose occurs, immediately contact the nearest poison control center and transport the patient to the nearest medical facility

Question 38

Where and how should you store medications?

Answer 38

Kept in original container and stored in locked cabinet Kept away from heat, direct light, dampness, freezing temperature Dry environment with temperatures between 15 and 31.7 degrees C (59-86F) Check expiration date

Question 39

What is acetaminophen and what does it do?

Answer 39

inhibits prostaglandins in the CNS but does not inhibit their synthesis in peripheral tissues Acts as an analgesic and reduces fever, no anti-inflammatory or antiplatelet properties No GI irritation – replacement for aspirin Overdosage – liver damage or death

Question 40

What is aspirin, what does it do and what are its side effects?

Answer 40

analgesic, antipyretic and anti-inflammatory S/s – GI bleeding, nausea, vomiting and development of gastric ulcers High doses – tinnitus and dizziness Used in children under 18 – risk of Reye syndrome

Question 41

What are nonsteroidal anti-inflammatory drugs (NSAIDs,), what do they do and what are their side effects?

Answer 41

Suppress inflammation and pain, produce analgesia, reduce fever Produce same effects as aspirin without many side effects Interfere with the biosynthesis of prostaglandins and other related compounds by inhibiting COX, an enzyme responsible for the synthesis of prostaglandins During inflammation – increased prostaglandin activity = increased BF, capillary permeability, permeability effects of histamine and bradykinin Inhibition of COX-2 Adverse effects – GI irritation, increase BP, renal impairment, hypersensitivity reactions, toxicity Taken with food/milk/water, never alcohol (risk of GI irritation, gastric ulcers) Treat mild-moderate pain associated with joints/muscles/headaches Treat inflammation associated with rheumatoid arthritis, tendinitis, bursitis – not effective for relief of severe pain Pain relief after 30 minutes up to several hours Ibuprofen (Advil), ketoprofen, naproxen sodium (Aleve)

Question 42

What are corticosteroids, what do they do and what are their side effects?

Answer 42

Steroid hormones produced naturally within adrenal cortex, can be produce synthetically Lipid-soluble, block the body’s natural response to inflammation by inhibiting the synthesis of chemical mediators Inhibit prostaglandin synthesis, act in several other ways Side effects – itching, burning, dry skin and fluid retention Rare – increase/decrease in appetite, dizziness, restlessness, facial/body hair growth, GI irritation, menstrual irregularities, optic pain Indicated for skin disorders, nasal inflammation, rheumatic disorders, skin infections Oral/nasal inhalation, injections, topically, orally

Question 43

What are the different local anesthetics?

Answer 43

Pain killers – inhibit the activity of sensory nerve receptors in the skin Skin does not respond well to aspirin or other oral analgesics Injectable – produces numbness by interfering with nerve function in a localized, subcutaneous, soft-tissue area (infiltrative anesthesia) Topical – applied to the skin, relieve pain associated with MSK injuries, stimulate nerve endings in the skin that respond to pain and to warm/cold sensations distracting the user from the original pain or itching (suffix –cane) Spray – temporarily freeze the skin in an effort to decrease pain, lasts for 1 minute, freezing action can damage skin and delay healing Skin irritation, systemic absorption can occur if too much is absorbed over large surface area

Question 44

What are muscle relaxants?

Answer 44

Block afferent messages that travel from the muscles to the brain Central – exert their effects with SC Direct – affect skeletal muscle cell Prescription only Prescribed for spasms with MSK injury Decrease local pain, spasm and tenderness, increase ROM General depression of CNS – dizziness, drowsiness, sedation

Question 45

What are topical antibiotics?

Answer 45

Antibiotics – substances that kill disease-producing bacteria, are used to prevent and treat infections Skin infections – streptococcus, staphylococcus, most treat both Used on small wounds such as abrasions – cream, ointments or powders Not designed for deep wounds – internal absorption of some can be toxic Used in small amounts, generally 3x daily and for not more than a week

Question 46

What are oral antibiotics?

Answer 46

Treat infection or cellulitis Selecting and administering antibiotics important – increase in antimicrobial resistance

Question 47

What are antiseptics?

Answer 47

Antiseptic – applied to living tissue to stop growth of microorganisms or destroy bacteria on contact and prevent infection Appropriate in cleaning/treatment of large, open skin wounds, come in sprays, powders and swab-on liquids Isopropyl alcohol, Betadine and tincture of iodine

Question 48

What are disinfectants?

Answer 48

chemical agents applied to nonliving objects Disinfect surgical instruments and cleanse medical equipment and facilities

Question 49

What are antifungal agents?

Answer 49

Treat infections caused by fungal cells Humans – fungal cells are either mold or yeast Molds – tinea pedis, tinea cruris, tinea corporis Yeast – candidiasis, moniliasis Applied twice a day, symptoms disappearing within a few days of initial treatment Cleanse area thoroughly before applying

Question 50

How does coffee affect the body and what does it do to it?

Answer 50

Low-level CNS stimulant that increases alertness and feelings of well-being Stimulant in fatigue states in combination with analgesic compounds Rapidly absorbed – 30-60 minutes peak levels, half-life of 3.5 hours Stimulates the secretion of adrenaline and except in the renal afferent artery causes vasoconstriction Enhancing the contractility of skeletal and cardiac muscle and assisting in fat metabolism Considered to be an ergogenic aid for prolonged endurance exercise activities in doses 3-6 mg per kg body mass Large doses (15-30 mg per kg) – lead to agitation, delirium, seizures, dyspnea, cardiac arrythmia, myoclonus, nausea, vomiting, hyperglycemia, hypokalemia Low doses via coffee consumption – tachycardia, palpitations, insomnia, restlessness, nervousness, tremor, headache, abdominal pain, nausea, vomiting Restricted or controlled drug when urine levels exceed 15-12 ug per mL

Question 51

How does tobacco affect the body?

Answer 51

Low-level CNS stimulant Nicotine – stimulating chemical and addictive substance in the product Cigarettes, cigars, smokeless tobacco Nicotine is absorbed into the lungs when using cigarettes/cigars, through oral mucosa when using smokeless tobacco Small doses = stimulate, large doses = depress Smokeless tobacco = not a safe alternative to cigarette smoking, better absorbed into bloodstream Smokeless tobacco – halitosis = discoloured teeth, oral abrasions, periodontal bone disease, tooth loss and leukoplakia (disease of mouth characterized by white patches and oral lesions on cheeks/gums/tongue, can lead to oral cancer)

Question 52

How does alcohol affect the body?

Answer 52

Most abused recreational drug Ingested – rapidly absorbed unaltered into the body Mostly absorbed in stomach and small intestine Absorption rate depends on: type/concentration of alcohol, the rate at which the beverage is consumed, current stomach contents, emptying of the stomach, body weight, gastric motility Alcohol is metabolized at a constant rate, 1 oz of alcohol per hour, depends on liver enzymes Lipid-soluble, crosses blood-barrier and instantly acts as a CNS depressant Majority metabolized in liver Small to moderate amounts – negative effects on psychomotor skills (reaction times, hand-eye coordination, accuracy, balance and complex coordination) Little to no benefit regarding energy metabolism or oxygen consumption Does not improve muscular work capacity Decrease performance levels, impair temperature regulation

Question 53

How does marijuana affect the body?

Answer 53

Naturally occurring cannabinoid that contains the active ingredient delta9-tetrahydrocannabinol (THC) Medically – antiemetic agent in conjunction with chemotherapy for patients with cancer, lowering intraocular pressure in glaucoma patients CNS – impaired motor coordination, decrease short-term memory, difficulty concentrating, decline in work performance CV system – tachycardia, changes in BP Effects depends on – route, dose, setting and previous experience Sport – reduction of max exercise performance, premature achievement of VO2 mac Inhibit sweating  increase in core body temperature High lipid solubility  detected for up to 2-4 weeks by testing

Question 54

How do diuretics work and how do they affect the body?

Answer 54

Help rid the body of unneeded water and salt through the urine, allowing the heart to pump blood more freely Carbonic anhydrase inhibitors – prevent action of carbonic anhydrase (an enzyme that produces free H+ ions, which are traded for sodium ions in the kidney tubules), Na, K, bicarbonate and water excreted in the urine Loop diuretics – used during emergencies, edema associated with chronic heart failure, cirrhosis of liver, renal disease Osmotic diuretics – promote diuresis in the prevention and treatment of the oliguric phase of acute renal failure Potassium-sparing – depress the reabsorption of sodium in the kidney tubules and increase sodium and water excretion, depress the excretion of K+ Thiazides – inhibit reabsorption of Na and Cl leading to moderate increases in the excretion of sodium, chloride and water Abuse – can impair thermoregulation, dehydration, decrease stroke volume, arrhythmia, electrolyte depletion

Question 55

What are anabolic-androgenic steroids and how do they affect the body?

Answer 55

30 natural and synthetically made derivation of testosterone Stimulate growth and accelerate weight gain Promote rapid synthesis of protein in the body by binding to androgen receptors at the cellular level, stimulation the production of ribonucleic acid with increases the synthesis of protein Active individuals – increase body weight, lean body mass, muscle size/strength Adverse effects – uncontrolled anger, explosive behaviour, increased appetite, sexual desires, lower pain tolerance

Question 56

What is human growth hormone and how does it affect the body?

Answer 56

Antiaging drug used to enhance muscular strength and growth, healing properties Side effect – acromegaly: gigantism characterized by costal and mandibular growth, vertebral/phalangeal/frontal bone growth, widening of joint spaces, accelerated osteoarthritis, soft-tissue swelling Athletes – combined with various testosterone derivatives, difficult to detect

Question 57

What are amphetamines and how do they affect the body?

Answer 57

CNS stimulants Sport – mask fatigue and pain to improve mental tasks Influence involuntary actions of the CNS Side effects – lower threshold for arrhythmias and provocation of angina leading to cardiac death, stroke, tremors, insomnia, psychosis, psychological addiction

Question 58

What is Ephedra and how does it affect the body?

Answer 58

CNS stimulant that increases serum levels of norepinephrine, can increase BP, heart rate, cardiac output, peripheral vascular resistance Side effects – increases heat temperature and body temperature

Question 59

What does blood doping and erythropoietin do to the body?

Answer 59

Stimulate RBC production of RBCs so that more oxygen is available for use during long-distance aerobic activities to enhance oxygen-carrying capacity and skeletal muscle performance

Question 60

What is a homologous blood transfusion?

Answer 60

Homologous transfusions use blood from another person/donor and transfuse it into the identified individual

Question 61

What is an autologous blood transfusion?

Answer 61

Autologous transfusions remove blood from the individual, freeze the blood and reinfuse the blood several weeks later

Question 62

What is creatine and how does it affect the body?

Answer 62

Nonessential dietary element found in protein-rich sources, such as meat and fish Synthesized primarily in the liver and is stored in skeletal muscle Hydrolysis of muscle phosphocreatine results in rapid production of ATP, needed for muscle contraction Oral creatine supplements  increase muscle phosphocreatine stores by 6-8% causing faster regeneration of ATP  shorter recovery periods and increased energy for repeated bouts of exercise Buffers lactic acid delaying muscle fatigue and soreness

Question 63

What is drug testing?

Answer 63

Drug testing discovers those individuals who may be experiencing problems Testing is performed to screen participants for evidence of drug use/abuse Drug testing protects individuals from injury or from causing injury to others Urine tests, blood tests, human hair tests, radioimmunoassay

Question 64

How would you avoid detection of drug use during drug testing?

Answer 64

Avoid detection Masking agents – diuretics used to counteract steroids-induced fluid retention and reduce concentration of banned substance Determination of drug half-life Substitution of urine