NR 293 - Exam 1 Questions and answers + rationales

Pharmaceutics

the dosage form that determines the rate of drug dissolution

Pharmacodynamics

- what the drug does to the body

- therapeutic effects

Selective Enzyme Interaction

when the drug binds to an enzyme molecule and inhibits (blocks) or stimulates the enzyme action with the normal target cell

Pharmacokinetics

- what the body does to the drug

- study of movement of drugs throughout the body

Absorption

being absorbed or used by the tissues

Fastest to Slowest Absorption Routes by Mouth

- Sublingual

- Liquid Suspension

- Capsule

- Tablet

- Enteric Coated Tablet

- Extended Release Tablet

First Pass Effect

oral doses of drugs are absorbed into the GI tract and metabolized by the liver, resulting in a reduced amount of bioavailability or active drug in the circulatory system.

Oral doses are generally higher to allow for this effect

Drugs that are Effected by First Pass Effect

- Elixir

- Tablets

- Capsules

enteral drugs

What drugs aren't effected by First Pass Effect?

- IV

- Sublingual

- Transdermal Patch

- Suppository

parenteral drugs

Half Life

- the time t takes for 1/2 of the drug dose to be eliminated from the body

-drugs with a long half life enables them to be taken less frequently

EX: ibuprofen has a half life of 2 hours, after 1 half life 200 mg will turn into 100 mg

Plasma

yellow fluid part of blood that holds the cells

Interstitial Fluid

fluid within the cells

Transcellular Fluid

part of extracellular fluid

Areas of Fast Distribution

- Heart

- Liver

Areas of Slow Distribution

- Muscle

- Fat

- Skin

Protein Binding Complications

if a person has a low protein , or albumin level, free drug will be circulating and can cause toxicity of the drug.

EX: a person with normal albumin levels is prescribed more than one drug that is highly protein binding. the prescriber will likely decrease the dose of both drugs to avoid drug toxicity

Normal Albumin Level

3.5-5.5 g/dL

Metabolism

use and transformation of drugs so that they can be excreted from the body

Where are most drugs metabolized/excreted?

- Liver

- Kidney

Neonates/Infants: Drug Metabolism

have immature liver and kidneys causing them to have decreased or poor metabolism and excretion of drugs

Cytochrome P-450

when drugs are bio-transformed through an enzyme to form fat-soluble metabolites that are easy to eliminate

Liver Failure: Drug Metabolism

have difficulty metabolizing certain drugs

Fast/Slow Acetylators

genetic conditions that affect how the liver metabolizes drugs

Excretion

drugs excreted through liver, kidneys (urine), hair, skin, breath, saliva, perspiration, feces, milk and bile

Six Rights of Medication Administration

- Right Patient

- Right Drug

- Right Route

- Right Dose

- Right Time

- Right Documentation

What should you do if part of the order is missing?

NOTIFY THE PRESCRIBER

EX: give mr. jones bactrim PO every 6 hours for UTI

(no dose is given)

Assessment

- always assess the patient before, during and after drug adminitrations

- nurses are legally bound as assessment is one of the roles of the RN

- failure to assess is a legal liability

Diagnosis

Nursing diagnoses

Planning

Plan of Care

Implementation

Interventions aimed at reaching desired outcome

Evaluation

always evaluate the therapeutic response of a medication

Definitive Therapy

administering antibiotics based on culture and sensitivity results (preferred method)

Drug Dosages

likely need to be decreased in patients with chronic renal failure, liver failure, concurrent use of medications metabolized by the same pathway.

Drug Interactions

Altered effects of drug as a result of interaction with other drugs or herbal supplements

Drug Routes

- IV

- Transdermal Patch

- Sublingual

- Subcutaneous

- Intramuscular

- Buccal

- Oral

- Suppositories

Empiric Therapy

administering antibiotics prior to getting culture and sensitivity results, based on experience/knowledge

Peak

highest concentration of drug in the systemic circulations (generally drawn 1 hour after drug is infused via IV)

Trough

lowest concentration of drug in the systemic circulations (generally draw just before the next dose)

Pharmacokinetics: Infants

infants at risk related to drug therapy and inability to effectively metabolize and excrete drugs due to immature renal and organ systems

Prophylactic Therapy

administering antibiotics as a preventive measure without a culture and sensitivity, prevent infection

EX: given before surgical procedure to prevent infection

Protein Bound Drugs

a drug's protein binding capacity enables the drug to be distributed to extravascular tissue and reach its site of action

Therapeutic Window

drugs with a narrow therapeutic window have a narrow margin of safety because they have more potential for toxicity

Superinfection

when high doses of an antibiotic kill the normal flora, another infection can occur simultaneously which is resistant to the antibiotic given for the original infection

Antiseptics

inhibit (not necessarily killing) growth on living tissue

neosporin

Disinfectants

destroys/kills organisms on non living objects

lysol

Bacteriostatic

inhibits bacterial growth

Clindamycin

Bacteriocidal

kills bacteria

Penicillin

Gram Positive

susceptible to antibiotics

Gram Negative

resistant to antibiotics

Culture and Sensitivity: Priority

- take a blood sample before starting antibiotic therapy

- purpose is to determine which microbe and which antibiotic will be most effective

Therapeutic Responses of Antibiotic Therapy

- decrease in fever

- WBC's normal

- decrease in redness/inflammation

- decreased drainage and pain

Normal WBC

4500-10000 mmm3

Secondary Infection

it is not uncommon for female patients to acquire a vaginal yeast infection after a course of antibiotics for a UTI

Food-Drug Interactions

Tetracycline with milk or cheese - decreased absorption of tetracycline

Drug - Drug Interactions

quinolone antibiotics with antacids or MVI or Fe - decreased absorption of antibiotic

Antibiotic

Having the ability to destroy or interfere with the development of a living organism. The term is used most commonly to refer to antibacterial drugs.

Antimicrobial

drugs aimed at destroying other microbes that cause infection such as viruses (HIV), parasites (malaria), and fungi (candida)

Sulfonamides

- Crystalluria is common

- Drink lots of fluids, hydration is key!

Syfamethoxazole

- sulfonamides

- bactrim can interact with warfarin (coumadin) and increase bleeding time

- many drugs interact with warfarin

Prothrombin Time/International Normalized Ratio

understanding the clotting time for a patient

Penicillins

- same family as cephalosporins

- cross sensitivity can occur

- patients allergic to PCN can have allergic reactions to cephalosporins

What should you do if a patient on penicillin is having difficulty breathing?

- stop IV infusion

- vitals

- physician

Clarithromycin (BIAXIN)

- marcolides

- used to treat strep throat, pneumonia, skin infections, H. pylori infection, lyme disease

- made from erythomycin

Marcolides

-works by interrupting protein synthesis in bacterial cells

Erythromycin

- ototoxicity (hearing loss, tinnitus)

- marcolides

Levoflixini/Levaquin

- quinolones

- serious side effect - tendonitis/tendon rupture

Aminoglycosides

- gentamicin sulfate (garamycin) is nephrotoxic

- dehydration in the patient can increase toxicity in the kidneys

- increase fluids if decreased urinary output

- ototoxic

What happens if you take Aminoglycosides and Cefazolin (cephalosporins)?

nephrotoxicity

Tetracyclines

- permanent discoloration of teeth if taken before 8 years old (binds to calcium on teeth)

- can decrease effect of oral contraceptives

- photo-sensitivity is a side effect (avoid direct sunlight)

- keep hydrated

- dairy products decrease effectiveness as well as antacids

Vancomycin (Vancocin)

important to administer over 60 minutes

Red Man Syndrome

occurs when vancomycin (vancocin) is given too quickly, can occur within 5-10 minutes after infusion (flushing, itching of the neck, face, torso)

Nitrofurantoin (Macrodantin)

treat UTIs but can cause stomach upset, take with food

Common Side Effects for Antibiotics

- fatigue

- anorexia

- headache

- dizziness

Taking Antibiotics

- always take with food, for antibiotics cause GI upset

- exception (tetracycline and dairy) decreases effectiveness

Agranulocytosis

- when absolute neutrophil count is <100/microliter of blood

- normal is 1500

- can lead to death from blood infection, septicemia

Granulocytes

- WBCs that make up part of the immune system

- contain enzymes that can kill bacteria and other organisms and break down substances that may harm the body

- without these one ahs a higher risk of developing frequent or chronic infections

Neutropenia

low number of neutrophils <1700 (normal is 3900-10000)

Patient is on IV antibiotic and states having difficulty breathing...

- STOP infusion

- call physician

- take vitals

- indicative of anaphylactic allergic reaction

Patient is on IV antibiotic that has white patches on their mouth...

- can be a minor irritation such as bacterial, viral or fungal infection

- can be something more serious like an oral cancer

- NOTIFY PHYSICIAN FIRST

What is the primary way to tell if antibiotic treatments is effective?

afebrile - normal temperature (indicates absence of infection, so we know it is working)

Monitoring Antibiotic reactions

- assess for allergic reactions such as difficulty breathing, tongue swelling, itching

- diarrhea and constipation are not indicative of allergy

Herpes Infection

- there is no cure

- can be treated to make patient more comfortable

Active Genital Herpes

- practice abstinence

- use all of the topical ointment and avoid sharing with partner if they contract virus

Acyclovir

- an antiviral that can have adverse renal effects

- if taken by IV, it is a vesicant (blister agent) so patient is at risk for extravasation (leaking on to surrounding skin)

- infuse slowly over 1 hour

Antiviral drugs kill...

healthy cells too, while killing viruses

Zidovudine (Retrovir)

-prevents transmission of HIV from HIV-infected pregnant women to the infant

-FDA Category C

Anti-TB Meds

- patients should not stop taking these meds

- mycobacterium can grow, make patient sicker and become antibiotic resistant

-need to be taken at the same time every day to keep blood concentration of drug consistent to combat mycobacterium

- Avoid alcoholic beverages due to liver toxicity

Rifampin

decrease the effectiveness of oral contraceptive

Peripheral Neuropathy: Anti TB Drugs

- numbness/tingling in extremities

- can occur when taking Anti-TB meds

- patient needs to notify health care provider

Taking Multiple Anti-TB drugs

given to prevent resistance of the mycobacterium tuberculosis microbe

Amphotericin B

- major anti-fungal medication given by (IV) to patients with serious systemic fungal infections

- always use an infusion pump for safety

IV Site: Amphotericin B

- monitor the IV site for signs of phlebitis and infiltration

- risk for extravasation

Amphotericin B: Adverse Effects

- fever and nausea

- give pre-medication with antipyretics such as acetaminophen (Tylenol) and antiemetics such as ondansetron (Zofran)

- if this occurs do not stop infusion or adjust the speed

Peripheral Neuropathy: Antifungals

stop immediately if patient develops this

Shake and Bake

- chills and fever

- occur during amphotericin B infusion

- notify the physician

Treatment of Vaginal Yeast Infection

- include a 2 week daily vaginal suppository as well as a 1 day oral (PO) treatment - fluconazole (Diflucan)

- 2 week is over the counter

- 1 day requires prescription

Metronidazole (Flagyl)

reddish brown urine that is normal to see during vaginal yeast infection treatment