Exam #2: Drug-Nutrient Interactions Flashcards
What types of patients are at risk for experiencing an adverse effect due to a drug-nutrient interaction?
1) Long-term dosing regimen (e.g. PUD/PPI–>B12)
2) Self-medicate
3) Pre-existing nutritional disease
4) Extensive surgical history
5) Take meds at meals
6) High potency vitamins or minerals
7) High alcohol consumption
8) Receive enteral or parenteral nutrition
9) Alter diet during dosing regimen
10) Poor diet
11) Gain or lose large amounts of weight
What is Alendronate (Fosamax)?
Bisphosphate used to prevent bone resorption
What causes decreased drug absorption of Alendronate (Fosamax)?
- Must be taken during the FASTING state
- Even liquids can reduce absorption
B/c of this, it is recommended that the drug be taken 2 hours prior to a meal
What is Ondansetron (Zofran)?
Antiemetic agent
How can absorption of Ondansetron (Zofran) be increased?
- Absorption is INCREASED by presence of food in the upper GI system
Slowing down the transit time and increasing mixing/churning will increase the amount of time for absorption.
What is Ciprofloxacin (Cipro)?
Broad spectrum antimicrobial agent
What is drug chelation?
Formation of a drug-cation complex
How does chelation affect absorption of a drug?
Chelation PREVENTS absorption
Describe how Ciprofloaxcin (Cipro) is chelated.
Cipro binds divalent cations e.g. Ca++, iron, and zinc
Because of chelation, what types of foods should be avoided when taking Cipro?
- Dairy products (Ca++)
- Fortified juices
- Liquid supplements
What is Omeprazole (Prilosec)?
Proton pump inhibitor used to suppress gastric acid secretion for GERD/ PUD
What is the effect of increased gastric pH e.g. with PPIs?
Reduction in the extraction of protein bound nutrients
What can PPIs inhibit the absorption of?
B12
B12 requires gastric acid and pepsin activation. PPIs decreased acid secretion and increased pH impairs gastric acid and pepsin.
What is Colestipol (Colestid)?
Antilipidemic agent used to treat hypercholesterolemia
What is the mechanism of action of Colestipol (Colestid)?
- Drug stays in the GI tract
- Sequesters bile salts in the GI tract and prevents enterohepatic circulation
Thus, the drug increases the secretion of bile salts (formed from cholesterol), causing the body to “pull” more cholesterol out of the body
What is the negative dietary impact of Colestipol (Colestid)?
In addition to bile salts, Colestipol will also:
- Bind fat soluble vitamins
- Prevent miccelle formation