Pharmacology Chapter 2 and 3 Flashcards
What is the Drug Cycle
Absorption, Distribution, Metabolism and Excretion
What is Absorption
AKA Pharmacokinetics: Medication moves from administration site to bloodstream; speed of absorption depends on a variety of different things
What affects the rate of absorption?
Route of administration: topical or systemic; solubility, pH, and concentration of medication; Length of contact; age; food; depth of breathing
Topical Medications
Condition of skin (scars, tattoos, eczema, etc)
Systemic medication
Oral, intravenous (IV), injection, patches
Distribution
Delivery of a drug to the site in need after it has been absorbed into the blood stream; barriers to distribution may be blood-brain barrier, blood-testicular barrier, and blood-placental barrier
Blood-brain barrier
This barrier protects the brain from any harmful substances. Psychotropic drugs may cross this barrier
Blood-placental barrier
This barrier protects the fetus from any harmful substances. However, alcohol, cocaine and some OTC medications may cross barrier and inflict harm onto the fetus
Blood-testicular barrier
This barrier protects the sperm from any harmful substances
Metabolism
also known as biotransformation; medication is transformed to a less active or inactive form (metabolite). This phase takes place in the liver, kidneys and intestines
Excretion
the process where waste products are removed from the body. Kidneys are the main organ of this phase; Lungs, bile, sweat glands and breast also participate in this phase
Accumulation of medication
The buildup of medication in the body leading to illness and adverse reactions.
Therapeutic level
the point which the drug is at its maximum desired effect.
Ototoxic
toxic to ears
Nephrotoxic
toxic to kidneys
Agonist
when two drugs work together for one drug to be more effective
Antagonist
when a drug makes another less effective
Side Effects
Mostly mild, some changes to diet and exercise may help relieve side effects
Central Nervous system side effects
agitation, delirium, hallucinations, confusion, disorientation, depression, sedation/drowsiness, decreased respirations, decreased circulation, dizziness and coma
Urinary System side effects
Fluid and electrolyte imbalance, abnormally high potassium levels, increased blood urea nitrogen levels
Hematology side effects
decreased white blood cells, decreased red blood cells, decreased platelets
Liver side effects
high liver enzyme levels in blood, jaundice
GI system
anorexia, nausea, vomiting, constipation, diarrhea, ulcers and colitis
Drug resource information for healthcare providers
There are comprehensive resources, cover medications in depth and only available as printed materials
Drug resources for patients
Clinically based resources include information on medication that patient will understand: how to administer, appropriate dose, identify indications and contraindications, patient education information; CD-ROM or digital downloads for smart phone. Package inserts that accompany drugs from manufacturer
Patients right to safety
Right patient, right drug (check three times), right dose, right time, right route (and technique), right documentation
How do you document medication the correct way
Medication name, dose, route/site, and for vaccines lot number and manufacturer
Medication names and abbreviations
safety is key; consolidation of all patient medication: patient needs, appropriate, accounting for other factors and schedule is appropriate; look alike/sound alike; abbreviations, when in doubt ask
Factors affecting medication administration
nutrition and physical activity: poor diet may reduce therapeutic level, check drug resource for food interactions, exercise can influence metabolism and increase speed of absorption; drug doses are based on the average body weight of 150 pounds.
Geriatric affects on medication administration
decreased absorption due to diminished GI function and congestion of abdominal vessels; slowed distribution because of low plasma protein levels lead to larger amount of unbound drug action; altered liver and kidney function can lead to accumulation; polypharmacy- multiple medications increase risk of drug interaction and side effects; sedative hypnotics, anticoagulants, NSAIDs, antihypertensive, and thrombolytics cause adverse drug events; patients with dementia may become agitated when given tranquilizers
Pediatric affects on drug administration
higher metabolism: rate of absorption is faster; lower body weight; injection site of choice for infants and small children is the thigh muscle; may become overhydrated; medication doses most commonly calculated with weight; neonate/premature: metabolism and excretion is impaired, central nervous system is more susceptible, medication miscalculation may become devastating due to size, use ototoxic/nephrotoxic drugs with caution, due to weight changes in pre mature/ neonates adjustment to dosing is as necessary.
Gender affects on administration
men have more muscle than fat so they absorb medication and distribute faster; men tend to have faster metabolism than women; antidepressants affect men and women differently due to hormones
Pregnancy affect on drug administration
blood-placental barrier protects fetus from certain medications; fat soluble medications more likely to cross barrier leading to possible death or malformation to fetus; medications that may cause malformation or death: teratogenic medication; fetuses are most vulnerable during first trimester due to vital organs forming; fetus is also vulnerable during third trimester due to accumulation of medication
Culture affects on medication administration
cultures whose beliefs are in science are more likely to depend on primary healthcare providers to choose drugs; more holistic cultures believe imbalances cause disease, less likely to use convention drugs, more likely to use herbs; others believe illness comes from evil spirits and may be alternative healers.
FDA guidelines for pregnancy
A- Safety established by human studies;
B- Presumed safe established by animal studies
C- Uncertain safety: animal studies show risk, weigh benefits of use
D- Unsafe: human studies show risk, weigh benefits of use
X- Highly unsafe: positive evidence of harm
Liver dysfunction
Metabolism of medication is affected
Kidney dysfunction
Excretion of medication is affected
Heart dysfunction
distribution throughout circulatory system of medication is affected
Ethical and safety considerations
patient information: education and participate in care; patient consent: the right to refusal; patient privacy; patient emergencies
