NURS 5334 PHARMACOLOGY FINAL EXAM STUDY GUIDE

MODULE 1 What are the BON rules and regulations for prescriptive authority for the advance practice nurse? It is determined by state law Schedule II meds cannot be prescribed by phone Texas is very restricted Describe the pharmacokinetic processes of absorption, distribution, metabolism and elimination and how differences in these areas affect drug action. • Absorption • Drug’s movement from the site of administration into the blood. • Distribution • Drug’s movement from the blood into the interstitial space of tissues and from there into cells. • Metabolism • Biotransformation is the enzymatically mediated alteration of drug structure. • Elimination • Combination of metabolism and excretion • Discuss the impact of food on drug absorption, drug metabolism and on drug toxicity and action—as well as the timing of drug administration. LIFESPAN • Hepatic metabolism and GFR increase during pregnancy, dosages of some drugs may need to be increased. • Rate of albumin to water decreases • Third trimester: Renal blood flow is doubled and renal excretion is accelerated (drugs excreted rapidly) • Tone and mobility of bowel decrease • Prolongation of drug effects Total (½ life increases) Understand stages of development in pregnancy • Conception: through week 2 • Embryonic period: week 3-week 8 a) Gross malformations can be produced by teratogens • Fetal period: week 9-delivery • Understand pregnancy labeling • 3 categories now a) Pregnancy, lactation, male & female reproductive potential • How do you decrease risk in the infant during breastfeeding? • Take meds immediately after breastfeeding, avoid drugs that have long half-lives, choose drugs that tend to be excluded from milk, avoid drugs that are known to be hazardous. • How do pediatric patients differ in their response to medications? • Absorption a) Oral? • Neonates: drug remain in the stomach longer which increases the levels, low acidity can affect the absorption of acid labile drugs b) Parenteral? • Reponses are slow and erratic. • Infancy: absorption is more rapid than in neonates & adults • Best avoided in infants c) Transdermal? • Greater skin permeability which increases topical drug absorption and increases the risk for toxicity • Distribution a) Protein binding 1. Neonates: less protein-binding—increased availability of highly protein bound drugs such as phenytoin, diazepam, and phenobarbital. Reduced dosages needed in these highly bound drugs. b) Blood Brain Barrier 1. Not fully developed at birth, drugs have easy access to the CNS, doses should be reduced. • Metabolism a) Hepatic function? 1. Liver hasn’t reached full maturation—sensitive to drugs eliminated by the CYP450. Liver’s ability to metabolize drugs increases about one month after birth. b) T half life 1. Decreased by as much as 48-72 hours • Excretion a) Renal? 1. GFR is significantly reduced at birth, drugs eliminated by the kidneys must be given in a reduced dosage and longer dosing intervals. • What education needs to be given to parents? • What to do if child spits out medication or throws it up • Effective education: dosage size and timing, route, technique of administration, duration of treatment, how to store the drug, nature and time course of the desired response, nature and time course of adverse reactions. Drug's movement from the site of administration to the blood Absorption Must be water soluble to absorb IV drugs Rapid absorption with water soluble drugs, slow with poorly soluble drugs. IM drugs How soon Rate How intense Amounts Same amount of chemical compound Chemically Equivalent Absorbed at same rate to same extent Equal bioavailability Drug's movement from the blood into interstitial space of tissues from there into cells Distribution Properties affecting drugs crossing a membrane Lipid/Water solubility pH Protein binding Size of molecule Affects ionization of drug pH ___________ molecules are more able to diffuse across a membrane Smaller What is distribution determined by? Blood flow to tissues Ability of drug to exit the vascular system Ability of the drug to enter cells Good perfusion = Good distribution Bad blood flow in _______________________________________. Abscesses and tumors High affinity for adipose tissue Lipid-soluble drugs Once a day is delivered to the organ or tissue by blood circulation, then it must ________________________. Exit the vasculature A drug trying to leave the vascular can be impeded by Blood brain barrier Drug can cross placenta Protein binding What drugs do not cross the placenta? Those that are: 1. Ionized 2. Highly polar 3. Protein-bound If drug binds to protein (albumin), what happens? The drug is stuck in the bloodstream If 2 drugs bind to proteins, what can happen? drug/drug interactions. Because of albumin-binding competition If albumin binding competition takes place, what happens? Increased concentration of displaced drug. Increased plasma drug level. Increased toxicity What determines the ability of a drug to enter cells. Lipid solubility and/or presence of transport system The enzymatically medicated alteration in drug structure. Metabolism AKA biotransformation Hepatic drug-metabolizing enzymes P450 System (Cytochrome P450 (CYP families)). What do P450 enzyme inducers do to the rate of metabolism Decrease rate of drug metabolism P450 enzyme inhibitors decrease rate of drug metabolism, which equals _______________________ which equals________________________. Decreased drug plasma levels Need for higher dose to be effective PY450 enzyme inhibitors _____________________ rate of drug metabolism = ____________________ drug plasma levels = need for _______________ dosing and watch for _________________. Decrease Increase Lower Toxicity Substrates are metabolized by P450 hepatic enzymes Therapeutic consequences of drug metabolism 1. Accelerated Renal excretion of drugs 2. Drug inactivation 3. Increased therapeutic action 4. Activation of prodrugs 5. Increased toxicity 6. Decreased toxicity The most important consequence of drug metabolism is Renal drug excretion Can't excrete ______________, so metabolic conversion of ________________ into __________________ can accelerate renal excretion. Lipid soluble drugs Lipid soluble drugs Water-soluble Metabolism can convert active compounds to inactive forms. Common end results of metabolism. Drug inactivation What does the role of the APN as a prescriber require? Critical thinking Advanced knowledge Higher level of legal responsibility Mnemonic--A SAFE MED Allergy Safety Adverse drug reactions Finances MOA Elimination Dosage and duration Common errors in prescription writing Wrong drug, wrong dose, drug interactions Omissions and illegibility Distractions Directions--do not use error prone abbreviations Legal requirements Quantity Duration of therapy Schedule ___________ are most dangerous with high potential for abuse. Schedule _______ is least potential for abuse 1, 5 Examples of schedule 1 drugs Heroin LSD Ecstasy Peyote Schedule 2 meds hydrocodone, cocaine, methamphetamine, methadone, hydromorphone, meperidine, oxycodone, fentanyl, adderall, ritalin Schedule 3 drugs Codeine, ketamine, testosterone (injectable) Schedule 4 drugs Xanax, soma, valium, ativan, ambien, tramadol Transfers regulation of the state's prescription drug monitoring program from DPS to Texas State Board of Pharmacy effective 9/1/2016 SB 195 APRNs and CSII x must be in facility-based practice. Pt must be admitted to hospital x 24 hours. May not write for any other purpose other than hospice care SB 406 Cornerstone of therapy for osteoporosis Bisphosphonates Fragility of skeleton due to loss of bone architecture Osteoporosis Caused by bone resorption that is out of proportion to bone formation (amount of bone that is formed is normal). Osteoporosis Causes of secondary osteoporosis Hyperthyroidism Use of steroids Anti-seizure medication Blood thinning agents Seen in men and women, beginning in the 8th decade of life. Caused by bone formation that cannot keep up with bone resorption (bone formation is slowed) Type 2 osteoporosis Therapy for osteoporosis Adequate dietary calcium and vitamin D Weight bearing exercise Smoking cessation Avoidance of ETOH Avoid: Steroids, anti-psychotics, anti-epileptics If steroids, antipsychotics, and antiepileptics must be used, this test should be obtained at baseline and then yearly. DEXA Drugs that can cause bone loss Aluminum antacids Anticonvulsants Antipsychotics Aromatase inhibitors Lasix Glucocorticoids Heparin Provera PPIs SSRIs Actos Levothyroxine WHO Fracture Risk Assessment Tool FRAX score What factors does the FRAX tool use to assess fracture risk? Age Gender height weight Hx of previous fractures All approved agents (except ________________) are anti-resorptives Forteo Prototype osteoporosis drug Alendronate (Fosamax) (Bonista) Describe how Fosamax is given Daily or weekly Given in AM with 4-8oz of water 30-60 min before breakfast. Must remain upright for 30 minutes after taking medication. What type of tablet is Binosto? Effervescent Approved for prevention and treatment of osteoporosis of hip and spine Alendronate (Fosamax) Rapidly cleared from plasma--binds to hydroxyapatite in the bone, once bound they are cleared over months to years, renally eliminated (cannot be given in severe renal disease GFR 35) Alendronate (Fosamax) Alendronate (Fosamax) side effects GI distress Esophagitis Osteonecrosis of jaw (with long-term use) Atypical fractures (with long-term use) Other bisphosphonates Risedronate Ibandronate Zoledronic Acid Second-line agents for osteoporosis Estrogens Selective Estrogen Receptor Blockers Raloxifene (Evista) What is the oral daily agent used for women intolerant to bisphosphonates? Raloxifene (Evista) What effects does Raloxifene have on bone and estrogen? Estrogen-like effects on bone and estrogen antagonistic effects on breast and endometrium