Pharm - Exam 1

Pharmacology

study of drugs that alter functions of living organisms

Pharmacotherapy

use of drugs to prevent, diagnose, or treat signs, symptoms, and diseases

Pharmacodynamics

drugs mechanism of action and effect on an organism, target cells

• Ligand-gated ion channel

• G protein-coupled receptors

• Enzyme-linked receptors

• Intracellular receptors

Medications

Drugs given for therapeutic purposes, can be given for local or systemic effects

Where do drugs come from?

Plants, animals, minerals, laboratories

Synthetic drugs are less likely to have allergic reactions, semisynthetic (antibiotics) are naturally occurring but chemically modified

Effects of medication

• Local: at site of application (local anesthesia, sunscreen)

• Systemic: taking into the body, circulated through bloodstream to sites of action and will be eliminated from body (most drugs given!!)

Drug classification

• Classified by specific body systems (bronchodilator), therapeutic uses (anti-inflammatory), chemical characteristics (sulfa drug)

Many drugs fit into multiple

Prescription vs. non

Controlled vs. noncontrolled substances

Prototype

• Individual drug that represents groups of drugs (usually first/original drug in class, most effective)

• Similar drugs are compared

Drug names

• Generic: original designation, lower case, law requires generic Rx to decrease cost (not absolutely chemically identical to trade)

• Trade/brand: pharmaceutical company, capital letter

• Patent: protects pharmaceutical manufacturer, expensive and time consuming, but others cannot manufacture drug

• Chemical name: reflects chemical structure

• DAW dispensed as written do not substitute

Properties of an ideal drug

• Effectiveness (most important)

• Safety: cannot produce harmful effects

• Selectivity: only the response for which it is given

Pharmacoeconomics vs. Pharmacogenomics

Pharmacoeconomics

• Costs of drug and effects (is it beneficial, storage, dispensing, administration, lab testing)

• Identify drug therapy to provide benefits at lowest costs

Pharmacogenomics

• Study of how one’s genetic makeup, or genome, affects the body’s response to drugs

• Helps providers choose drugs and doses that work best for an individual

Prescription vs. Non-prescription drugs

Prescription

• Written by provider

OTC

• Do not require prescription, still regulated by law

• Can mask the symptoms of underlying diseases, inaccurate self diagnosis, may result in drug interactions (adverse drug reactions), can lead to overdoses/toxicity

FTC suppresses misleading

FDA regulates manufacture, distribution, ads, and labeling of drugs

Controlled substances

Categorized according to therapeutic usefulness and abuse potential

Classes:

• Schedule I: high abuse potential, psychological effects, no accepted medical use, only dispensed for research (heroin, LSD, X)

• Schedule II: high abuse, severe dependence ability (opioid, codeine, morphine, hydromorphone, methadone, oxycodone) locked and no refills

• Schedule III: less abuse, prescription expires in 6 months

• Schedule IV: less abuse (antianxiety, benzodiazepines)

• Schedule V: limited abuse, 18, must be recorded

Drug approval processes

• Phase 0: chemicals tested on lab animals (3.5-4yr)

• Phase 1: chemicals tests on healthy human volunteers (1-3yr)

• Phase 2: drug tried on informed 100-300 patients w/ disease (2-3yr)

• Phase 3: drug tested in vast clinical market patients with disease/diaries/placebo (2-3yr)

• Phase 4: obtain FDA approval, continual evaluation(2-3yr)

• 1 in 10,000 are approved

Black box warning

• Withdrawal of approved and marketed drugs: serious adverse effects that become evident only when drugs are used in large, diverse populations

• Ex. antidepressants (suicide)

Rights of medication administration

• Right drug

• Right dose (how much?)

• Right patient (correctly identified)

• Right assessment (do they need it?)

• Right route

• Right time

• Right reason

• Right documentation

• Right patient education

• Right evaluation (check to see if it worked)

• Right to refuse

3 medication checks : read label after selecting container, after take medication and compare to MAR, right before giving dose to pt

Pharmacokinetics

• How the body interacts with administered substances for the duration of exposure

• ADME (absorption, distribution, metabolism, excretion)

Absorption

• How the drug enters bloodstream

• Orally: has to get into stomach/intestine and get absorbed into blood

• First-pass effect: drug is reduced in concentration before reaching bloodstream

Distribution

• Transport of drug molecules within the body

  • Protein binding: combines with protein for complex, and only the free/unbound portion acts on cells

  • BBB: controls substances from passing through

Metabolism

• Body chemically alters drugs into water-soluble, so that it can be excreted (biotransformation) LIVER!!!

• CYP 450 inhibitors - inhibit drug metabolism, CYP 450 inducers - accelerates drug metabolism

Excretion

• Kidney, urine

• Bile, saliva, sweat, feces, milk, exhaled air

Serum drug levels

amount of a drug in the blood at a particular time

Ligand-gated ion channel

• When specific drug attaches to channel’s receptor, specific ions can pass through (GATE)

• Membranes of neurons

• GABA receptors, nicotinic ach

• Lorazepam, ketamine

G Protein-coupled receptors

• In cell membrane

• When substances bind, signals are sent to a G protein which seperates

• Dopamine receptors, etc.

• Antihistamines, beta blockers

Enzyme-linked receptors

• When a ligand binds to the binding site, the receptor changes, and the change activates an enzyme, which triggers reactions to change gene expression

• Insulin, growth factors

Intracellular receptors

• Drugs are hydrophobic and lipid-soluble

• When drugs combine with receptor, transcription occurs and desired actions

• Steroids

Agonist vs. Antagonist drugs

• Agonist: activate receptors (oxycodone)

• Antagonist: block action of other drugs by blocking (Naloxone)

Drug-related variable that affect drug actions

• Dosage: reason for use, potency, route

  • Loading dose: initial higher dose to be given before given a lower maintenance dose

• Route: oral is slow, IV is fastest, transdermal is very slow, inhalation/IM is fast

• Drug-diet: tyramine / antidepressants, vitamin K / anticoag, calcium / antibiotics, grapefruit / statins

• Drug-drug: altered drug metabolism

• Age

• Body weight

• Ethnicity

• Pre-exisiting conditions, psychological factors

• Gender

Drug toxicity

• Goal of treatment: start treatment ASAP, stable ABCs, reduce absorption/increase elimination, antidotes

Opioids: Narcan (naloxone)

Warfarin: Vit K

Heparin: Protamine sulfate

Digoxin: Digoxin Immune Fab

Acetaminophen: Acetylcystein

Activated charcoal if poison ingestion/overdose (do not use if aspiration risk or obstruction)

Med errors

• Risks: incorrect dose, incorrect diagnosis/meds, undetected reaction, not following guide, interactions

• Nurses need to have enough drug knowledge to recognize an error in an order

Changes to prevent medication errors

•  Computerized provider order entry (order isn’t on paper, less issues)

• Bar coding (can give error message and alarm, records drug/dose/time)

• Point of care (Time)

• Less abbreviations

• Accurate med history, avoids errors, updated list given to next provider and patient

• Electronic prescribing

Medication orders

• Full name of pt. drug, dose, route, frequency, date, time, signature of prescriber

• Orders: typed or written into record

• Verbal orders: written on order sheet, signed by person taking order, later cosigned by prescriber

Drug prep and dosage forms

• Enteric-coated tablets are coated with a substance insoluble in stomach acid

• Controlled-release: long-acting

• Transdermal formulation: absorbed clonidine, estrogen, fent, nitroglycerin (over period of time)

• Pump: external or implanted under skin, refillable or long acting w/o refill

• Solution/ointment/cream/supp: topically or mucous membrane

Injections

• Sterile needles and syringes: measure and administer parenteral meds

• usually 25 gauge (small) is used for sub q injections, and 22-20 (bigger) is for IM

• S/C: upper arm, abdomen, back, thigh

• IM: deltoid, ventrogluteal, vastus lateralis

• IV: veins on back of hands and forearm

Children implications

• Faster toxic level, as there are less receptors so molecules are roaming

• Slower gastric emptying, delayed intestinal mobility, different routes, more water so more water-soluble, immature liver and kidneys

Safety: always check with another nurse, use weight-based doses, Leur lock syringes for IV, use pumps, teach caregivers, be safe with storage/access/administration

Geriatric implications

• Older adults are more prone to antibiotic-resistant infections, more drug-drug interactions, slowed body systems (increased toxicity)

• More fat, prolonged half-life, less receptors

• Beers criteria: inappropriate medications for adult populations, need to be adjusted, ANTICHOLINERGICS (benadryl)

• More likely to be dehydrated, decreased gastric acidity (more basic), increased infections

• POLYPHARMACY, (slow and low), altered mental and visual status, always consult the provider before stopping a medication

Pregnancy implications

• No drug is considered safe during pregnancy

• Folic acid for neural tube abnormalities (spinabifida)

• Physiologic changes: more blood volume/output/flow/weight/fat/kidney flow/hormones

• Drugs are more diluted, and dosage may need to increase, more excretion in kidney until 3rd trimester

• Lactation: many drugs reach milk, use alcohol in moderation, caffeine, smoking, drugs

• Fetal therapeutics: digoxin (fetal tachy/heart failure), levothyroxine (hypothyroid), penicillin (syphilis), corticosteroids (decrease resp. distress)

estrogen, progestin, Ortho-Novum

• Estrogen: BATS (antibiotics, alcohol, smoking, seizure meds (inc preg)) St. John’s lowers effectiveness (inc. risk of endo cancer, thrombo, dementia, breast cancer) teach about ACHES

• Progestin: increased CV risk, bone loss (If HRT, test liver function)

• Ortho-novum: prevent pregnancy, acne

  • MOA: inhibit ovulation, prevent follicle from forming, thin endometrium, thicken mucus

  • Interactions: Do not take while pregnant, breastfeeding, smokers 35 years or older, reproductive cancers, abnormal kidney/liver function (STOP if jaundice), diabetes, high BP, migrane

  • Adverse: gallbladder disease, thromboembolism

  • Drug interactions: (dec.) anticonvulsant, barbs, benzo, St. John, Topiramate, succinimides

  • Teaching: assess knowledge, adherance, lowest dose/shortest duration, VTE signs, intact uterus only

sildenafil (Viagra)

Class: PDE5 Inhibitors

MOA: vasodilate smooth muscle

Use: ED (po), pulmonary arterial hypertension for males

Adverse: irreversible loss of vision, sudden hearing loss, priaprism

Side effect: priaprism, headache, flushed

Interactions: NITRATES (they already dilate), (inc) alcohol, antihypertensives, grapefruit juice, saw palmento (dec) fatty foods

Teaching: no more than once a day

finasteride (Proscar)

Class: 5-Alpha Reductase Inhibitors

Use: BPH, male pattern baldness (po)

MOA: reduce enlargement (shrink) prostate

Adverse: impotence, gynecomastia, reduced libido, ejaculatory disorders, decreased sperm

Side: hypotension

Interactions: (dec) testosterone, anticholinergics (inc) saw palmetto

Teaching: 3 TO 6 MONTHS, females do not take, esp if pregnant or lactating do not stay near, no abnormal kidney function pt, no regard to food once per day, check for improved urinary function, unable to void (pass urine, fever) call provider, DIZZINESS, do not give blood

tamulosin (Floxmax)

Class: Alpha 1-Adrenergic Blockers

MOA: RELAX muscles in prostate/bladder neck

Use: BPH, female urethral calculi expulsion

Adverse effects: POSTURAL HYPOTENSION

Side effects: Ejaculation failure/retrograde/decreased, weakness, sleepy, insomnia, stuffy/runny nose, sore throat, vision blurry

Contraindications: Cimetidine, alpha blocker (antihypertensives), anticoagulants, PDE5 (inc. orthostatic hypotension)

Teaching: immediate effects!, enzyme system is essential, take 30 after eating same time, DO NOT OPEN/CLOSE/CHEW, assess for decreased frequency/hesitancy/urgency/dribble/nocturia/improved force, pain, assess for OH/insomnia, vision, congestion, etc.

Insulin basics

• Rapid acting (Lispro): 5-15 minutes onset, peak 1-2 hrs

• Short acting (Regular): 30-60 min, peak 2-3 hrs, can be given IV

• Intermediate acting (NPH): 2-4 hrs, peak 4-12 hrs, can be combined with short

• Long acting: 24 hr, steady control, CANNOT MIX, NO PEAK

MUST ROLL CLOUDY INSULIN

Insulins

• Reg: short-acting, peak 2-3 hrs, can wait 30 min to eat, IV use, DKA, hospital, GIVE BEFORE REG (clear before cloudy)

• NPH: intermediate, 4-12 hrs peak, eat immediately, pumps/meals, GIVE AFTER REG (clear before cloudy)

Class: Insulins

Use: Hyperglycemia, treating type 1 and 2 DM, and GDM

Adverse effects: hypokalemia, hypoglycemia, lipodystrohy, allergic rxn, edema

Side effects: weight gain, injection site reaction, mild hypoglycemia

Contraindications: Beta-blockers (inc. effects), corticosteroids and diuretics (dec. effects)

Teaching: Rotate injections, avoid problem areas, balanced diet/exercise, clean skin, carry sugar with you, can use open vial for up to 28 days, safe for pregnancy/lactation

glyburide (glynase)

Class: sulfonylureas (oral)

MOA: stimulate beta cells to release insulin (hypoglycemia effect)

Use: insulin for those with some beta-cells, type 2 DM

Adverse effects: hypoglycemia (common), GI upset, sunburn

Contraindications: Type 1, sulfa allergy, severe renal/hepatic impairment, PREGNANCY (macrosomia)

Teaching: Elder pt. have higher hypoglycemia risk, 30 minutes before meals

metformin

Class: biguanide

MOA: reducing the production of glucose from liver

Use: can be taken alone or with others, type 2 diabetes (no weight gain!)

Adverse effects: LACTIC ACIDOSIS (sob)

Side effects: GI issues, metallic taste, vitamin B12 deficiency

Contraindications: steroids, thyroids, oral contra, antipsychotics, pseudophedrine, dye, nsaids, ace inhibitors, diuretics, alcohol

Teaching: discontinue 48 hrs before and after contrast test, take with meals, do not skip meals

sitagliptin (Januvia)

Class: dipeptidyl peptidase 4 (DPP-4) inhibitor

MOA: increases incretin hormones

Use: lowers blood sugar levels

Adverse effects: pancreatitis, severe joint pain, heart failure risk

Teaching: 30 min before meals, refrigerate, discuss herbal supplements with provider, drink fluids, seek attention if level is above 250

glucagon

Class: anti-hyperglycemics

Use: severe hypoglycemia, patient is unconscious and unable to swallow

Adverse effects: vomit, avoid with tumor, increase HR and BP, headache, itchy

Contraindications: warfarin (+ anticoag effect), anticholingerics, indomethacin, allergy to glucagon

Teaching: cannot take oral meds, if IV, use dextrose over glucagon, POSITION ON SIDE, assess LOC, check blood glucose, can be given IM SQ IV

Diabetic tests

• Hba1c: percentage of glycated hb in blood for 2-3 months, explain it doesn’t replace daily test, low Hb may have low A1c, iron deficiency may have high A1c

  • normal: below 5.7%

  • pre: 5.7%-6.4%

  • diabetes: 6.5% or higher

• Fasting blood sugar: glucose after 8hr fast, water is permitted

  • normal: less than or equal to 100 mg/dL (to 125 can be pre, higher is diabetes)

epoetin alfa

Class: erythropoiesis-stimulating agents

MOA: helps produce more RBCs

Use: anemia w/ CKD, anemia w/ HIV, below 10 g/dL

Adverse effects: HTN, increased risk of MI and STROKE

Contraindications:

• age: retinopathy for infants, do not give in multi-dose vial

• be careful with people with existing HTN

• chemo-meds (lenalidomide) → thrombus formation

Teaching: Do not shake, freeze, or dilute; iron supplments, discard after 21 days, check HB, HC, goal is no more than 12 g/dL, check BP, make sure clean and healthy lifestyle, take foods with vitamin C for absorption

filgrastim

Class: colony-stimulating factors

MOA: stimulate WBC by bone marrow

Use: patients with bone marrow transplant or chemo-induced neutropenia, neutropenia

Adverse effects: flu-like symptoms, bone pain, splenic rupture (L upper quad, L shoulder)

Contraindications:

• age: peds: spleen enlargement, pregnancy: preservative-free solution

• known sensitivity, e. coli

Teaching: Do not shake, use once, do not give w/i 24 hrs of chemo infusion, take tylenol for bone pain, isolation, RECOGNIZE ISSUE IF WBC IS MORE THAN 100,000 cells/mm3

immunizations

• Adults have 1 dose in older age of MMR, Tdap every 10 years, pneumococcal at 65 yrs, no live vaccines during pregnancy, flu for children over 6 years

• Flu

  • IM injections for everyone, only nasal if they can have live

  • New vaccine every year, strains change each year (protection 2 wks after injection) does not cause flu

  • Do not give is GBS, allergic rxn, severe egg allergy

  • Wait if someone is mod-severe sick to give vaccine

• MMR

  • Live virus

    • 1st dose: 12-15 months, 2nd dose: 4-6 yrs, 1 dose if born after 1957

    • No for pregnancy, immunocompromised, hx of allergy to neomycin/gelatin, thrombocytopenia, seizure hx

  • Lifelong immunity, tylenol not aspirin

cyclophosphamide

Class: Alkylating agent

MOA: treat cancer by decreased DNA synthesis

Use: Cancer, autoimmune

Adverse effects: myelosuppresion, hemorrhagic cystitis, alopecia, GI distress, anemia, bleeding, fatigue, mucositis, N/V, neutropenia, myelosuppression, thrombocytopenia, nephrotoxic, hepatotoxic

Contraindications: active infections, pregnancy/lactation, azole antifungal, erythromycins, protease inhibitors, CYp3A4, myelosuppression

Teaching: drink 2-3q of water, urinate frequently, avoid crowds, neutropenic precautions, iron foods

• hemorrhagic cystitis

methotrexate

Class: Antimetabolite/antifolate

MOA: Antineoplastic, intereferes with DNA synthesis, ectopic pregnancy

Use: Treatment of cancer, chemotherapy, autoimmune

Adverse effects: Bleeding, fatal opportunistic infection, change in mental status, nephrotoxic, photosensitivity, hepatotoxicity, alopecia, anemia, bleeding, fatigue

Contraindications: pregnancy/breastfeeding, blood dyscarias, immunocompromised, alcoholism, azole antifungal, erythromycins, protease inhibitors, CYp3A4 inducers 

Teaching: Immunocompromised, avoid crowds, wear masks, get vaccinated but not live vaccines, once a week, folic acid, iron-rich foods, schedule/route/dosage are important, leak around tissue (extravasation), free flow of IV fluid into the vein and assess

• avoid aspirin, alcohol, BC before and after 6 months

infliximab

Action: TNF alpha blocking

Use: autoimmune

Adverse effects: serious infections/malignancies, infusion reactions, hepatotoxicity, CV, neutropenia, leukopenia, thrombocytopenia, auto-immune diseases, rash, HTN, skin injection site rxn, chills, dyspnea, chest pain

Contraindications: active infections, heart failure, hypersensitivity, methotraxate, echnacea, live virus

Teaching: infections prevention, TB tests, infusion monitor, cancer risks, vaccines (no live), delayed reactions

cyclosporine

Class: Immunosuppressant

MOA: Inhibits T-lymphocyte activation, reduces Interleukin-2 (IL-2)

Use: Transplant rejection, autoimmune disorders

Adverse effects: Nephrotoxicity, HTN, infection risk, high risk of malignancy,hyperlipidemia, hirsutism, hyperkalemia

Contraindications: grapefruit, don’t mix with other antirejections, antibiotics/fungals, st johns

Teaching: Avoid crowds, live vaccines/fresh flowers/raw food, test WBC, can increase risk of infection, do not crush/chew, sun safety, don’t take hrs prior to transplant, do not give in plastic/Styrofoam, dilute neoral w/ orange/apple juice, drink all immediately, infection risk, no other drugs, same time everyday, don’t rinse syringe, same time every day, do not miss dose

Radiation

-       Can cause DNA damage, long exposure is harmful (non-ionized)

-       EBRT - external, avoid putting things on site, loose clothes, sun protection

-       Brachytherapy - private room, time/dis/shield principles, cluster care, limit visitors, use lead shielding, radiation badges

-       Side effects: pruritis, erythema, burning, sloughing, anorexia, N/V, diarrhea, bone marrow depression