Elimination and Distribution Flashcards
Which drug penetrates the prostate gland and is effective in bacterial prostatitis?
Ciprofloxacin
Which drug is a non-sedating antihistamine because it cannot enter the brain?
Fexofenadine [Allegra]
Which drug is transported into the proximal tubules and is rapidly excreted by the kidneys?
Penicillin
What type of drugs are distributed to alveolar spaces and eliminated by lungs?
Inhalation anesthetics
What drug is a treatment for osteoporosis in postmenopausal women that is transported by the liver into the intestines where it is reabsorbed (enterohepatic recirculation)?
Raloxifene [Evista]
What are the determinants of drug distribution?
Organ blood flow Barrier to drug diffusion Adipose tissue Tissue binding protein Plasma binding protein Drug transport Ion tapping
If an organ has higher blood flow then they will receive _____ of the drug per unit time and will experience ____.
Larger amounts, larger initial effects
Even though these organ will have a lot of drug the high concentration will not last long because;
They will diminish as the drug is redistributed to sites with less blood flow
Which drugs are sedative/hypnotics that will produce initial, short, profound CNS effects after IV admin?
Benzodiaepines
Diazepam [Valium]
While many endothelial cells have pores for rapid diffusion, some have tight junctions. How must a drug travel in a cell with tight junctions vs one without?
Transcellularly through tight (across)
Paracellularly in endo (around)
Which types of drug are the only kind which can rapidly diffuse across tight junctions?
Lipophilic drugs
How is the blood brain barrier a special case in drug distribution
Capillaries have tight junctions and are wrapped in capillary glial cells
Endothelial cells have P-glycoprotein that pumps drugs out
In what case would the normal BBB restriction of hydrophilic drugs be broken?
Ischemia and inflammation
If a drug is lipophilic and distributes into adipose, what must have this to achieve its desired effect.
Larger initial bolus
To bind a drug to tissue a _____ is needed to achieve the desired effect.
Larger initial bolus
Which drugs highly bind to plasma proteins like albumin?
Acid drugs
Which drugs highly bind to plasma proteins like alpha1-acid glycoprotrin?
Basic drugs
When a drug binds to plasma proteins you need ____ because its more difficult for the drug to leave the vascular compartment.
More
If a highly plasma-protein bound drug is displaced by another drug what might happen?
May lead to a drug-drug interaction due to rapid availability of unbound or free drug
What is an example of a drug-drug interaction due to displacement?
Unconjugated bilirubin from albumin
May cause precipitate bilirubin causing encephalopathy in newborns
Transportation mechanism may ____ or ____ the distribution of drugs to certain tissues.
Increase or decrease
What could competition for transport lead to?
Drug-drug interactions
What is ion trapping used for?
Used to distribute drugs into the urinary compartment to inc the urinary excretion of poisons
If you overdose of aspirin or phenobarbital what can be done?
Alkalinization of the urine with systemic administration of sodium bicarbonate
