Pharm 2, 3, 6
drug interaction
-Additive effect -Synergistic effect -Antagonistic effect -Displacement -Interference Incompatibility
liberation
Drug released from dosage form -Drug released from dosage form and is dissolved in body fluid -Process of converting oral drug can be influenced by food and water in the stomach
Antagonist:
Drugs that attach to a receptor but do not stimulate a response
Agonists:
Drugs that interact with a receptor to stimulate a response
Most drug interactions that alter absorption take place in the ___________
GI tract
Duration of action:
How long the drug has a pharmacologic effect
A patient reports postoperative pain, and the nurse administers morphine (a narcotic analgesic) intravenously to ease the pain. Fifteen minutes later, the nurse notes that the patient is very drowsy, respirations are slow and shallow, and oxygen saturation is low. The nurse administers another drug that decreases the action of the morphine. What is this effect called? a) Displacement b) Antagonistic c) Interference d) Synergistic
IDK
what is the fastest absorption route?
IV
gender affects weight therapy
In almost every body system, men and women function differently; experience disease differently
Drug Stages After Administration
LADME: Liberation Absorption Distribution Metabolism Excretion
changes in absorption
Many alterations in absorption can be managed by separating the times of administration
Changes in Distribution
Many interactions that cause a change in distribution usually affect the binding of a drug to an inactive site
allergic reaction:
Occur among patients who have previously been exposed to a drug and whose immune systems have developed antibodies to the drug
illness affect on metabolic rate Patients with _________ failure generally will excrete drugs at a _________ rate
Pathologic conditions may alter rate of absorption, distribution, metabolism, and excretion of drug kidney failure, slower rate
Nocebo effect
Patient's negative expectations can result in a less-than-optimal outcome
placebo effect
Patient's positive expectation can positively affect the outcome
Unbound drugs:
Pharmacologically active portion
drug interactions
Said to occur when the action of one drug is altered or changed by the action of another drug
Drug receptors:
Specific sites where drugs form chemical bonds
Pharmacodynamics:
Study of interactions between drugs and their receptors and the series of events that result in a pharmacologic response
Peak action:
Time at which the drug reaches the highest concentrations on the target receptor sites
Enteral:
Via the gastrointestinal tract by the oral, rectal, or nasogastric routes
Onset of action:
When the concentration of a drug at the site of action is sufficient to start a physiologic response
drug actions
onset of action peak action duration of action
body weight affects drug therapy Considerably ________ patients may require an increase in drug dosage to attain the same therapeutic response
overweight
metabolic rate affect on drug therapy Patients with higher-than-average metabolic rate tend to metabolize drugs more ___________ Chronic _________ enhances metabolism of some drugs
rapidly smoking
Absorption rate depends on ____________, ______________, and _______________
route, blood flow, solubility of the drug
Drugs are "bound" to proteins in the blood during _______________.The more a drug is bound to a protein, the less available it is to the ______________. Some medications can cause binding or unbinding of another medication, increasing or decreasing its effect
transportation, circulation,
A patient is being started on a new drug that has been used safely by many people for years. The patient has no known allergies, and the nurse administers the drug correctly. Suddenly the patient experiences cardiac arrest. What is this type of reaction called? a) Allergic b) Mutagenic c) Idiosyncratic d) Therapeutic
allergic?
Subcutaneous and intramuscular injection absorption is affected by _________________
circulation
changes in excretion Drug interactions that cause a change in excretion usually act in the ________ ________ by changing the ______ to enhance or inhibit excretion
kidney tubules , pH
Organs with ____________ blood supply receive the distributed drug most rapidly
largest
Primary organ of metabolism is the _______; other sites are GI tract and lungs
liver
two ways to elicit drug interactions
-By agents that, when combined, increase the action of one or both drugs -By agents that, when combined, decrease the effectiveness of one or both drugs
Adverse Effects of Drugs
-Desired action -Side effects -Adverse effects (common and serious) - Idiosyncratic reactions: Occur when something unusual/abnormal happens when drug is first administered - Allergic reactions: Occur among patients who have previously been exposed to a drug and whose immune systems have developed antibodies to the drug
half life of drugs
-Factors modifying the quantity of drug reaching a site of action after a single oral dose
Drug Blood Level
-When a drug is circulating in the blood, a blood sample may be drawn and assayed to determine amount of drug present -Important for certain drugs, like anticonvulsants - If drug blood level is low, dosage may be increased; if it is high, dosage must be reduced
All drugs are processed in the body through pharmacokinetics. What is the correct order that drugs pass through the body? a) Liberation, absorption, distribution, metabolism, excretion b) Distribution, metabolism, liberation, absorption, excretion c) Biotransformation, liberation, distribution, absorption, excretion d) Excretion, distribution, liberation, absorption, metabolism
A
Percutaneous:
Absorbed through the skin and mucous membranes - Inhalation, sublingual, or topical
psychology effects on drug therapy
Attitudes and expectations play a major role in a patient's response to therapy; willingness to take medication as prescribed
Parenteral:
Bypasses the GI tract by using subcutaneous, intramuscular, and intravenous injection
When the nurse administers a 50-mg dose of a drug with a half-life of 6 hours, how many milligrams will remain in the body at 24 hours? a) 25 mg b) 12.5 mg ' c) 6.25 mg d) 3.13 mg e) 1.56 mg
D 6.25% remains, so 3.13
excretion
Depends on GI tract and kidneys -Elimination of drug metabolites and some of the active drug from the body - Kidneys are the major organ of excretion; some excreted in feces
distribution
Depends on circulation to be transported throughout body -Drugs are transported throughout the body by body fluids to the sites of action - Protein binding and fat solubility affect distribution - Organs with largest blood supply receive the distributed drug most rapidly - Some drugs cannot pass through the bloodbrain barrier or the placental barrier
metabolism
Depends on enzyme systems T-he process whereby the body inactivates drugs -Primary organ of metabolism is the liver; other sites are GI tract and lungs
absorption
Depends on route of administration -Drug is transferred from entry site into the body's circulating fluids -Absorption rate depends on route, blood flow, and solubility of the drug -Subcutaneous and intramuscular injection absorption is affected by circulation -Intravenous medications are absorbed fastest -Topical medications applied to the skin can be influenced by skin thickness and hydration
Affects on Drug Therapy
age body weight gender metabolic rate illness psychology
drug responses in the body
drug receptors pharmodynamics agonists antagonists
routes of administration
enteral parental percutaneous
Antacids increase the ________________ and can inhibit the dissolution of __________ tablets
gastric ph ketoconazole
age affects drug therapy _______ and the _______ tend to be most sensitive to drug effects Aging process brings about changes in body ________ and organ ________
infants and the very old composition, function
change in metabolism -Drug interactions usually result from a change in metabolism that involves _________ or ___________ the enzymes that metabolize a drug
inhibiting or inducing -Serum drug levels usually increase a result of inhibited metabolism when drugs are given concurrently