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Comp 19 lecture
pharmacokinetics and pharmcodynamics - pharm tech
Question | Answer |
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pharmacokinetics | encompasses the many different components of the actions of the body on a drug (Levels of the drug throughout the blood and tissues, absorption of the drug throughout the body, overall distribution, reaction of the drugs with other drugs, patient compliance, and life of the drug (bioavailability, half-life, bioequivalence, and elimination. |
bioavailability | THE RATE AT WHICH A DRUG BECOMES AVAILABLE TO THE SITE OF ACTION FOR WHICH IT IS INTENDED |
half-life | The amount of time it takes the body to break down and excrete half of a drug |
bioequivalence | The comparison between drugs either from different manufacturers or in the same company but from different batches of a drug; i.e. brand to generic |
therapeutic level | The desired effect of a drug with minimal side effects. |
four processes of pharmcokinetics | absorption, distribution, metabolism, and elimination |
absorption | Medications are made to get though natural body barriers, such as the skin, stomach, intestines, blood-brain barrier, and other membranous tissues |
absorption of drug effective | How well the drug passes through these barriers (absorption) is the one factor that determines its ultimate effectiveness. |
Factors that may affect absorption | Amount of drug dissolved, dosage form, route of administration |
ways for drugs to be absorbed | drugs are absorbed through mucous membranes or injected |
distribution | After a medications is absorbed, it is distributed throughout the bloodstream into tissues, membranes and, ultimately, organs |
distribution of a drug | Distribution of a drug is not necessarily equal though the body |
when drugs are distributed | the drugs bind to blood proteins to some degree like albumin (made by liver) |
albumin | Albumin is a water-soluble protein made in the liver and circulated throughout the body by the blood stream; serum albumin is main protein of human blood plasma |
opioids | bind to pain receptors to stop pain; also can stop breathing, respiratory depression, if too much is in system. |
Narcan | reverses respiratory depression caused by opioids; knocks opioid off it's receptors |
metabolism | Breakdown of drugs; drug molecule is changed or altered; most metabolism takes place in the liver |
First pass effect | associated with PO (by mouth) drugs; many orally administered drugs travel to the liver |
first pass drugs | lower a drug's bioavailability and are given in larger doses |
loading dose | larger first dose given to achieve a higher concentration of drug in the bloodstream, then titrated down usually i.e. Z-Pack |
Elimination | sometimes referred to as excretion; Elimination is the last phase of a drug’s life in the body |
ways drug can be excreted | Via the kidneys, feces, exhalation, sweat glands, and breast milk; urination and bowel movements are the common methods of excretion |
drug to food interaction and drug to drug interaction | impact the amount or activity of another drug |
drug to drug interaction | i.e. nitrates and ED meds |
drug to food interaction | broccoli and warfarin (vitamin K rich greens usually); grapefruit juice and statins ( lovastatin and simvastatin) |
constipation or diarrhea | variable that affect pharmcokinetics; constipation inhibits elimination of drug when needed and diarrhea eliminates it too quickly (so does vomiting) |
disease states or illnesses such as cardiac issues | affect what you may be prescribed |
pharmacodynamics | is the study of drugs and their action on a living organism. (What the drug does to the body) |
examples of drug classes and their effect on body - pharmcodynamics | Increase bone mass with bisphosphonates, decrease in BP with antihypertensive agents, and decrease inflammation with NSAIDs |
sequence of events | Absorption,distribuiton, bind to targeted receptor causing a cascade of events that lead to drug’s response |