HOW DO DRUGS WORK?
ADDITIVE
2 drugs with a similar action that are taken together to get desired effect. Work differently at receptor sites. 1+1=2
PHARMACODYNAMICS
All drugs bind to receptor site on the cells. They don't change the cells function. They modify the rate at which the cell functions. Speed up, slow down or block it. All drugs do SOMETHING to the receptor site. All cells have receptor site
ANTAGONIST
Drug binds to receptor site and there is no effect, just blocks it. The drug job was to block it or stop what is going on. Can be competitive or non-competitive
NON-COMPETITIVE
Drug that binds to different receptor sites and as new receptor site gets used up by the drug. The drug makes more receptor sites to outnumber and add to area to cell. Histamines are released when there is an allergic reaction, epinephrine takes over
ED
Effective dose.
PHARMOKINETICS
Has to do with how drugs get in our body, where they go and how we get them out.. movement through the body. 4 main catagories in pharmokinetics, absorption, distribution, metabolism /biotransformation, excretion
½ LIFE
How long it takes for ½ of the drug to be excreted from the body. Trying to determine the dosage. Every drug has (5) ½ lives and each ½ life has a time associated with it.
IDIOSYNCRATIC REACTION
Idio don't know. Have a reaction to a drug, it is unexplained, didn't know about it.. not a documented thing - just the reaction you had unexpected. Not the norm reaction that occurs.
TERATROGENIC
Latin for "monster producing". If you were to take a drug that could affect an unborn child... baby could be born with birth defects.
LD
Lethal Dose
LOCAL
One small area and tissue gets affected. EX: if you use topical acne cream, the area may become dry, red, flaky.
WHAT ALTERS A DRUGS EFFECTS???
Patient's age and weight Drug interaction Root of administration (how taken) Patient compliance Drug interaction Tolerance Allergy Smoking Sex and hormones pregnancy *** Grapefruit Juice**** Placebo effect - has no effects, but you think it has an effect it works
SIDE EFFECT
Predictable know it will happen if drug is taken: dose related, bothersome symptoms and usually affects non target organs. Benadryl makes you sleepy
TOXIC EFFECT
Predictable: drug given to people who have cancer to kill cancer, but it causes kidney failure.
DRUG ALLERGY
Rash - anaphylactic
Onset
Short time period. When it is taken to When it starts working
EFFICACY
The maximum effect of a drug. What is it doing and at what point does it stop doing it.
DOSE - RESPONSE CURVE
Therapeutic amount: (desired effect is what your trying to get out of it.. like pain medication to get rid of pain) more does not make it better. The measure of a drug's safety
LOG - DOSE EFFECT
comparison to determine how potent the drug is. Comparing 2 drugs, but which is stronger (need less to get good result)
ENTERAL
directly into the GI tract. Orally, rectally sublingual
AGONIST
drug binds to receptor sites and it does something, there is an outcome (produce an affect)
ABSORPTION
drug is taken from site to circulating blood. If drug has high first past effect it goes to the liver (goes to liver and starts to get metabolized there) need drug to work quickly do not want first pass drug. Different types of administration get drug into body faster: IV Sublingual Inhaled IM (intermuscular) Sustained released (patch) Orally Suppository (Glycerine)
1/2 life calculation
half life = 4 hours. 4 hours x (5)1/2 lifes = 20hrs In four hours, half of the medication is out of the body. So it takes a drug 20 hours to get out example.. not all are 4 hours. Drug takes 300 hours to get out of body = divide by 5 to see how long each half life is for.
DISTRIBUTION
how it is delivered to the tissue where the problem is. Always delivered via blood stream. Some organs are more heavily vascular than others, ex: brain, heart, kidneys have more vascularity drugs get there more quickly.
Duration
how long something lasts.
EXCRETION
how the drugs bi-product exits the body. most drugs leave through urine via the kidneys. Some come out your lungs or sweat glands. Drugs are also excreted through mammary glands
INTRAPERITONEAl
in the abdomen (stomach) area... type of dialysis
PARENTERAL
inhalation, topical, injection. Anything not going through the digestive tract.
INTERFERENCE WITH NATURAL DEFENSE MECHANISMS
interact with the body's natural defenses system: organ transplant: . For someone with a transplant so that the body doesn't attack the new kidney or transplant.
INTRAVENOUS
into a vein
INTRAMUSCULAR
into the muscles of arm and butt
INTRADERMAL
just below the epidermis. TB test
SUBCUTANEOUS
just below the skin insulin is injected just below the skin
TOPICAL
on top: skin or mucosa... rub on sunscreen.
TRANSDERMAL
patch for a release of medication
ED50
produces an effect in 50% of the people taking it.
ADVERSE REACTION
reaction that mild to severe, not a side effect. More deaths occurs from this than Car accidents, HIV and breast cancer
INTRATHECAL
spaces within the spinal column.
POTENCY
the amount of the drug you need to take to get a desired effect.
COMPETITIVE
the drug competes with the receptor site, Blocks the site and the additional amount of drug that is introduced wins. Sodium potassium pump to maintain homeostasis. Usually Na is outside of a cell, and K is inside the cell...To feel pain, Na goes into the cell and the K goes out. Local blocks the Na which blocks the pain.
LD50/ED50
therapeutic index. Measurement of the drugs safety
INHALATION
through your lungs
POTENTIATION
two medications that have a similar affect but they enhance each other. 1+1 = 4
METABOLISM BIOTRANSFORMATION
way your body changes the medication in order to excrete it. Most are metabolized by the liver. Some liver conditions can have a problem metabolizing the drugs; hepatitis, liver disease. Also cardiovascular disease (heart failure heart doesn't pump properly... will keep drugs in system longer) and age. words are used interchangeably. In pharm book = metabolism... in local book = biotransformation
Peak
when it's most absorbed.
