ADME Flashcards
(59 cards)
What is absorption?
Requires movement of medication from the GI tract to the general circulation
Is all drug necessarily absorbed? Why or Why not?
No because not all drug reaches the systemic circulation as an active drug
What is the difference between absorption and bioavailability?
Absorption = transportation of the unmetabolized drug from the site of administration Bioavailability = rate in extent to which the drug is absorbed
What is the rate-limiting step for most solid dose form drugs?
Disintegration and dissolution
FYI question: Define rate-limiting step
Step with the slowest rate that is slowing the whole process down
What is the rate-limiting step for liquid medications in solution?
Blood perfusion of the intestines
What 4 factors could affect the blood perfusion of the intestines?
- Disease states
- Edema
- Surgery
- Sepsis
What 6 factors can alter medication absorption?
- Presence of other drugs
- Presence of food
- Formulation of medication
- Route of administration
- Location of the distal tip of the enteral tube
- Gastric emptying
What are 3 approaches to enhance absorption?
- Use liquid medications to bypass the dissolution step
- Administer adequate fluids with liquid medications or pulverized tablets
- Administer additional free water to flush in conjunction w/ scheduled medications
If tablets are used to bypass the dissolution step, what should be done before administration?
Should be pulverised
What is the benefit of administering fluids with liquid medications or pulverized tablets?
Expands stomach and enhances gastric emptying
What is 1 factor that could inhibit absorption?
Placement of distal tip of enteral tube (stomach vs. duodenum vs. jejunum)
Example: Itraconazole tablets require an acidic environment for dissolution, which enteral tube would be great choices for itraconazole tablets?
Orogastric, nasogastric and gastrostomy because it ends in an acidic environment
(T/F) - Itraconazole tablets in a post pyloric administration have a great absorption?
FALSE - It has poor absorption
For a post pyloric administration, which itraconazole formulation would be best to be given?
Liquid formulation - medication is already dissolved bypassing the rate dissolution step
Example: Ciprofloxacin (fluoroquinolone antibiotic) is absorbed mainly in the upper part of the intestinal tract. Will it be absorbed properly if administered by a jejunostomy tube?
NO - that’s below the upper part (duodenum) of the intestinal tract
What 4 medications are best taken on an empty stomach?
- Penicillins
- Tetracyclines
- Rifampin
- Levothyroxine
Before a patient is administered a medication that is best taken on an empty stomach who is also on a tube-feed - how would one proceed?
Hold feeds 30-60 mins before medication administration
After a patient is administered a medication that is best taken on an empty stomach who is also on a tube feed - how would one proceed?
Hold feeds 30 mins after medication administration
If feeding schedule has been jeopardized, what should be done in order for the patient to receive 24-hour nutritional needs?
Re-adjust feeding schedule
What are some GI intolerances during tube feeding due to the formulation of some drugs?
- N/V/D
- Cramping
- Increased gastric residuals
If GI intolerances occur, for example, why should the clinician review the medication profile?
To determine if a drug’s route of administration should be changed or change the drug to equivalent therapeutic drugs for less GI intolerance occurance
Name 3 medications that delay gastric emptying or decrease GI motility
- Anticholinergics
- Aluminum-containing antacids
- Narcotics
Name 2 prokinetic drugs
- Metoclopramide
- Erythromycin
