Intro to Pharm pt 3

feces, urine, sweat, exhaled air

In what ways do the kidneys eliminate drugs

Half Life

What is the time it takes for amount of drug in body to decrease to one half of its peak

duration

Why is half life important for dosing schedule and for _____ of drug's effect on the body. It is also dependent on hwo the body processes and gets rid of the drug, taking seconds to hours to days, even weeks

4-5

How many half lives does it take for 94-97% of a drug to be eliminated, so after these the plasma concentration of a given drug will be below a clinically relevant concentration and thus be considered eliminated

oral forms

tablets, capsules, liquids, suspensions, elixirs and lozenges

oral sites

swallowing, sublingual, buccal, nasogastric tube and gastric tube

oral contradictions

Issues with difficulty swallowing, delayed gastric motility and vomiting can create issues with oral administration, and may need to be administered on an empty or full stomach

-you may also be able to crush, cut and dilute some forms

oral advantages

most common route, safe, inexpensive, easy to administer, and convenient for patient/caregivers

oral disadvantages

patient but be cooperative, variable absorption per patient, GI disruption

topical forms

powders, sprays, creams, ointments, pastes, oil and suspension based lotions

topical sites

applied directly to mucous membranes or skin-transdermal, eye, ear, nose, rectal or vaginal, will need to have gloves to clean skin

topical advantage

painless w localized effects and limited adverse effects

topical disadvantage

varied application, varied absorption and some forms can be very expensive

inhalation forms

MDI, DPI and neb solution

Inhalation sites

airway opening to lungs, requires a significant amount of education and specialized equipment for proper delivery

inhalation advantage

painless, directly absorbed by lung tissue (decreasing systemic absorption)

inhalation disadvantage

improper administration, poor inspiratory effect, integrity of lung tissue

Parenteral forms

powders for reconstitution, vials and fluid bags

parenteral sites

intramuscular, subcutaneous, intravenous, intradermis, requires careful training and prep

Parenteral advantages

Bypass first pass effect, directly into tissue

parenteral disadvantage

invasive, painful, expensive, specialized equipment/training

pharmacodynamics

What will help you administer medications safely and to evaluate patient outcomes, and the goal is to produce the most effective and least toxic chemical for therapeutic use

mechanisms of drug action

1. replace or substitute missing chemicals (ie. ssri to make you happier)

2 increase cell activity

2. decrease cell activity

4. interfere will cells that cause cell death

agonist

what is a drug that interacts with receptor sites to cause the same natural activity that would cause at that site

(fits perfectly to allow full potential to lock into)

FULL activation

partial agonist

What is a drug that binds to the same receptor site as agonist drugs but produce less than the maximum response produced by a full agonist

(less activation, we wont see the full activation, ie. forms of narcan to HELP with withdrawal)

LESS activation

antagonist

what is a drug that reacts with receptor sites to block normal stimulation and therefore prevent the effect of that stimulation (competitive antagonist)

(fits directly into block and prevents stimulation and stops receptor site)

(ie beta BLOCKER)

non competitive antagonists

what is a drug that reacts with specific receptor sites on a cell and prevents the reaction of another chemical with a different receptor site on that cell

selective toxicity

what is the ability of a drug to attack only those systems found in foreign cells

(we want it to get bad bacteria but not to damage the actual tissue, so eliminate bad bacteria, keep good bacteria)

drug enzyme interactions

what work by blocking single step in enzy,e cascade causing normal cell function disruption