Lecture 1 Flashcards
Describe the 5 rights of pharmacology
- drug
- patient
- dose
- route
- time
Examples of correctly assessing and evaluating pharmacology in patient care:
- pre-administration assessment (is patient BP already too low to take more hypertensive meds?)
- Dosage and administration (does dosage/route make sense?)
- Evaluating and promoting therapeutic effects (see what BG to give the correct amount of insulin)
- Know what adverse effects are so you can minimize likelihood
- Know what drugs can interact to result in adverse effects
- Know how soon someone can get a medication
- Keep toxicity of drugs in mind
What are the three types of drug names?
Chemical name (paracetamol), Generic (Acetaminophen), Trader (Tylenol)
What are the four phases of drug activity?
- Absorption (from site of admin to blood/circulating fluids)
- Distribution (from the blood through the interstitial space and to the cell of action/target cell)
- Metabolism (what happens when the drug is altered, usually happen in the liver)
- Excretion (in urine or bile)
What are some factors that affect absorption of a drug?
- rate of dissolution (only available when dissolved)
- Absorbing surface (intestines need a large surface area so the microvilli can absorb)
- Blood flow (need good blood flow to get meds to places to absorb)
- Lipid solubility of drug (if lipids are available for lipid soluble medications)
- PH partitioning (specific ph is neccesary to properly absorb meds)
What is the difference between parenteral and enteral route of administration?
Enteral: Oral/PO
Parenteral: Everything other than oral/through GI tract. IV, IM, SQ
What are the pros/cons of IV meds?
Pros: No barrier to absorption, rapid onset, can give large amounts of fluid, dispersed and circulated quickly
Cons: Costly, inconvenient, not reversible, easily infected, risk of embolism, drugs HAVE to be water soluble
How quickly do IM medications take effect?
Absorption determined by blood flow and drug solubility. Usually within 10-30min.
How quickly do SQ medications take effect?
Blood flow isn’t as good as IM so it is absorbed slower
Describe the barriers to absorption of the enteral route
Has to move through the epithelial cells (move through cells) of the GI tract lining and then through the endothelial cells (move around cells) of capillary walls.
Medication needs to be soluble
GI PH needs to be right
Bowel movement has to take place
Food near the medication may affect dissolve, chem structure, absorption
Other drugs taken at the same time
Drug coatings/compounds make drug favorable for absorbing or not
What are disadvantages of enteral absorption
everyone has different absorption because their GI is different
Has potential to be inactivated by food, other drugs, gastric acidity
the drug goes though the liver before becoming systemic and is chemically changed so that it is no longer effective
Pt has to be awake to take PO
If patient voids quickly (vomiting, diarrhea) less/no change of absorption
What are some alternative route of med admin
Topical, inhaled, rectal/vaginal suppositories, direct injection (joints, heart, CNS)
What affects distribution of a drug
Blood flow, ability to enter/exit vascular system (most drugs exit at capillary cells but can be inhibited by barriers such as blood-brain or protein binding barriers), ability to enter cells
Describe the blood brain/protein binding barriers
Blood brain: Tight junctions at capillary cells in brain
Proteins binding: Med binds to a protein in the vascular system and can’t leave to do what it needs to do b/c too big
T/F: All drugs have to enter cells to be metabolized and excreted?
True. Some drugs have to enter the cell to act while others work attached to the outside of the cell