drug absorption, pharmacogenetic and interaction

  1. What are factors affecting drug absorption?
    • Rate of dissolution
    • Surface area
    • Blood flow
    • Lipid SOlubility
    • pH-partioning
    • GI-hormones
    • Nervous System
    • Disease
    • Drugs
    • Food
  2. Onset is defined as:
    rate of absorption
  3. Intensity is defined as:
  4. Amount of absorption
  5. What are the physiological processes in the GIT?
    • Secretion: Transport of fluids, electrolytes, peptides, and proteins into lumen of GIT
    • Digestion
    • Absorption
  6. Where is most food absorbed?
    Proximal area of the small intestine: duodenum
  7. Tell me about the buccal route of administration
    • Good blood suppplyfast absorption of drugs
    • Bypasses first pass effect
  8. What is the enzyme in buccal area that digests starch?
    Ptyalin salivary amylase
  9. What protein is in saliva to help lubricate food?
    Mucin a glycoprotein
  10. Tell me about esophagus absorption
    Very thick very little absorption, no dissolution, short transit time
  11. Where does enzymatic digestion of proteins and peptide occur?
    In the duodenum
  12. Where does maximum absorption
    occur and why?
    In the duodenum because there is a high surface area with the micro villi, villi, brush border and very good perfusion
  13. Tell me about the small intesine
    • Long, highly vascularized
    • High transit time
    • Good adsoprtion
  14. Tell me about the colon
    • Limited drug absorption, exception of sustained release
    • Bacteria metabolism of drug , efflux pump
  15. Delay in gastric empyting causes what with regard to drugs?
    • Delay in drug absorption
    • degradation of acidic sensitive drugs
    • Gastric irritation by drugs
  16. How does high fat containing food affect absorption of highly lipid soluble drugs?
    Enhances absorption
  17. T/F food can affect the integrity of dosage form
    T
  18. T/F Foods can cause dose dumping
    T theo-24
  19. WHat does a high volume of fluid do to the stomach?
    Distends the stomach and speeds up emptying
  20. What are methods of studying factors affecting drug absorption?
    • Gamma scintograph, labels drug with gamma rays and use a gamma camera to track the drug
    • Mannitol: effect small intestine transit time, reducig drug uptake
    • Codeine: slows down the GI transit diminish drug absorption
    • Lactulose: accelerates GI transit time, enhacer drug absorption
    • Remote drug delivery capsule: cotains a pH sensor, and radio transmitter
    • Osmotic pump system
  21. Pharmacogenomics
    the study of genetically controlled variations in drug response/effect
  22. monogentic
    Is due to allelic variation at a single gene
  23. Polygentic
    due to variations at two or more genes
  24. POlymorphic
    frequency occurring monogenic variant
  25. What are the factors that effect genetic polymorphism for pharmacokinetics?
    • Transporters
    • Plamsa protein binding
    • Metabolism
  26. What are the factors that effect genetic polymorphism for pharmacodynamic?
    • Receptors
    • IOn channels
    • Enzymes
  27. How will a fast acetylaters repond with hypersensitivity?
    Decrease hyper
  28. How will a slow acetylaters repond with hypersensitivity
    INcrease hyper
  29. How does food affect drug absorption? WHY??
    • May decrease drug absorption
    • Food Drug binding
    • Can either increase or decrease drug absorption
  30. Why should some drugs be taken on an empty stomach?
    • Food can decrease their absorption
    • Food will delay their absorption
  31. What is the consequence of taking drugs with grapefruit juice?
    There will be a greater plasma concentration
  32. What are the active ingredients in grapefruit juice to make them interact?
    • Naringen, metabolized by enteral bacteria to NARINGENIN = a specific 3a4 inhibitor
    • Furanocoumarins = cyp inhibitor
  33. What should patient avoid while taking benzodiazepines?
    COFFEE cause an increase excitability decreasing therapetic effects
  34. What are the high risk pt?
    elderly, multiple meds, multiple diseases, renal or liver
  35. WHat are high risk drugs?
    • narrow therapeutic index
    • Enzyme inhibitors and inducers
  36. What are two example of pharmacodynamic drug interaction?
    • Increase toxcity of digoxin from diuretics
    • Alcohol and benzodiazepines
  37. What is the defintion of pharmacodynamic drug interactions?
    Drug a changes patient reponse to drug b without affecting pharmacokinetic of drug b
  38. What is an example of a drug interaction that can happen before administration?
    IV compatability
  39. What is the definition of pharmacokinetic drug interaction?
    A drug affects the ADME of another drug
  40. How can a drug alter its absorption?
    • Changing the gi pH
    • drug binding in the gi tract
  41. What are the two types of drug interactions?
    • unidirectional
    • bidirectional
  42. What is the example of drug inteaction that affects drug absorption that he keeps on talking about?
    Ca and tetratcycline

    Tetra forms a complex with Ca making it an insoluble complex
  43. What is an example of a drug interaction that affects drug elimination?
    • Probenecid and pen vk
    • INcrease in renal blood flow inhibition of active tubular secretion
  44. What are the diseases that he listed that affect drug absorption?
    • Parkinsons
    • Achalasia
    • Achlorydria
    • surgical conditions
    • HIV
    • CHF
    • Crohns
    • Celiac
  45. What are the drug classes that interact with other drugs absorption?
    • Anticholinergic; slows gi motility, delay drug absorption
    • Metoclopramide: increases peristalsis
    • Antacids:
    • Cholesteramine
Author
ba
ID
139192
Card Set
drug absorption, pharmacogenetic and interaction
Description
drug absorption, pharmacogenetic and interaction
Updated