5 stages of medication administration 5 stages of medication administration -liberation -absorption -distribution -metabolism -excretion liberation
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[Show More] medication dissolves into fluids libera tion process dosage form goes from capsule/tablet into active form that is dissolved in the GI tract so it can be transported into blood generally half an hour absorption process where meds are transferred from site to circulating fluids (blood, lymph) enteral medication administered directly through GI tract -oral, rectal, nasogastric, nasojejunal parenteral bypass the GI tract -subcutaneous(skin) -intramuscular(muscle) -intravenous(vein) percutaneous through skin & mucus -inhalation -sublingual (under tongue) -topical (on the skin) -eye, ear, nose, drops pharmacodynamics what the drug does to the body pharmacokinetics what the body does to the drug half-life of drug Time it takes for a drug to decrease in amount by half what does rate of absorption depend on? rate of blood flow polypharmacy multiple drug therapy required by chronic illness gastric pH less than or equal to 4 gastrointestinal absorption influenced by -gastric pH -gastric emptying time -enzymatic activity -blood flow of mucous lining and intestines distribution how the medication is circulated by the body fluids (generally blood) to the site of action fat soluble absorbed, stored, and transported in fat water soluble dissolve in water, move easily into bloodstream, can't be stored in the body organs that receive medications faster because of extensive blood supply -brain -heart -liver -kidneys areas that receive medication slower because of less extensive blood supply -muscle -skin -fat distribution depends on what two factors -protein binding -lipid solubility protein binding the ability of certain drugs to bind to plasma protein albumin protein in blood that medication attaches to drugs that use fat -antidepressants -phenothiazines -benzodiazepines -calcium channel blockers metabolism the body inactivates the drug- creating drug metabolites first pass metabolism the body (typically the liver) metabolizes the drug and reduces its concentration before it is released into systemic circulation Cytochrome P450 The general name for a large class of enzymes that play a significant role in drug metabolism and drug interactions pro drugs drugs that are administered in an inactive form, which is metabolized into an active form excretion elimination of drug metabolites and sometimes the drug itself two primary sites of excretion -GI tract -kidneys nephron functional unit of the kidney potassium a drug that is reabsorbed in the nephron onset of action when the concentration of a drug at the site of action is sufficient to start a physiologic response peak action the time at which the drug reaches the highest concentrations on the target receptor sites duration of action The length of time the concentration of a drug in the blood or tissues is sufficient to elicit a response serum drug levels drug levels in the blood therapeutic range concentration of drug in the blood serum that produces the desired effect without causing toxicity peak level highest plasma concentration of a drug (time required for drug to reach maximum response) trough level lowest concentration of drug in blood when should you draw blood before next administration? 30 mins before agonists stimulate a response antagonists prevent a stimulus from happening partial agonists drugs that interact with a receptor to stimulate a response but inhibit other responses reasons why we administer medication -prophylaxis -diagnosis -therapy prophylaxis given to prevent something from happening -hepran prevent blood from clotting common adverse effects less serious effects of a drug, other parts of the body responding urticaria severe itching anaphylactic reaction allergic reaction that leads to respiratory distress, severe bronchospasm, and cardiovascular collapse clinical indication why we administer specific drugs lipid solubility more lipid soluble means that it can be absorbed more readily and pass more easily through cell drug interactions when the action of one drug is altered or changed by the action of another drug additive effect two drugs with similar actions are taken for an increased effect -better pain relief synergistic effect combined effect of two or more drugs is greater than the effect of each drug alone antagonistic effect one drug interferes with the action of another displacement first drug is displaced from protein binding sites by the second drug - the drug becomes active & gives more interference first drug inhibits the metabolism or excretion of second drug incompatibility first drug is incompatible with the second drug and causes deterioration when mixed drug tolerance the body becomes accustomed to the effects of a particular drug over a period of time Idiosyncratic effect unusual, unexpected response to a drug that may manifest itself by overresponse, underresponse, or response different from the expected outcome polypharmacy The use of multiple medications generic name common name, first letter not capitalized, FDA named trade name registered and used as a name that is restricted to owner, usually manufacturer, first letter is capitalized classified drugs according to body systems the effect (GI tract, cardiovascular system) therapeutic drugs therapeutic use or clinical indications -antacids, antibiotics, antihypertensives, diuretics, laxatives physiologic or chemical action drugs anticholinergic, calcium channel blockers opioids -controlled substance -must be locked at all times -record waste with 2 nurses standing order given for a specific number of doses PRN order administer as needed single order carried out only once stat order single order, emergency use (typically within the hour except in the ICU) inconsistencies pyxis doesn't have enough drugs parts of medication order -pt name -date & time order is written -name of drug to be administered -dose of drug -route drug is to be administered -frequency of administration -signature of person writing order before administering medicine the nurse must have....? -current license to practice (legally & ethically [Show Less]