Drug Nutrient Interactions Flashcards
DNI Classification Type I
Ex vivo. Interactions occur outside the body
DNI Classification Type II
Absorption phase. DNI’s that alter the bioavailability of the drug. Occurs primarily in the GI or mucosa.
DNI Classification Type III
Physiologic Action
Alteration in kinetics (metabolism, distribution)
DNI Classification Type IV
Elimination Phase
DNI Classification Steps.
- Identify the precipitant agent
- Identify the object agent
- Identify the MOA
- Predict the clinical outcome
- Consider management changes
Differentiate between incompatibility and instability.
Incompatibility means the DNI is a physical interaction (i.e. precipitation) and instability means the DNI is a chemical interaction (i.e. maillard reaction or glycosylation)
What are drugs that cause stability issues in PN solutions?
H2 blockers Insulin Folic Acid Iron Dextran Heparin Ascorbic Acid Octreotide L-Carnitine Thiamine Albumin L-Cysteine
What type of insulin can be used in PNs?
Regular Insulin
Humulin R, Novolin R
What H2 blocker is preferred in PNs?
Famotidine and cimetidine
What is the concern with calcium and phosphate?
Precipitation (solubility risk)
What are some ways to prevent precipitation of Ca and Phosphate?
The higher the AA concentration the better. Acidic pHs. Keep at low temperatures When mixing add Ca last. Don't add electrolytes via Y-site. Don't mix with 3:1 PNs
What amino acid solutions are good to prevent calcium and phosphate precipitation?
Aminosyn II and Clinisol 15%
What is a way to improve TNA Solution’s (3:1) compatibility/stability?
Dual chamber bag, but there can be lipid contamination.
What is the most important vitamin to supplement?
Thiamine
How often do you give B12 during a vitamin shortage?
Monthly
During trace element shortages what elements are the most important to supplement?
Zinc
Selenium
Copper
Why is a Neonatal/Pediatric TNA (3:1) risky?
Because of high calcium and phosphate concentrations.
What is placed in Pediatric TNAs to help with Ca/Phos issues?
L-cysteine
It is a conditionally essential AA and it acidifies the TNA.
Why is calcium and phosphate included in pediatric TNAs?
For bone growth
How many micrograms of aluminum are allowed to be in large volume parentals (LVP’s)?
25mcg/L
What did the FDA establish as a safe amount of aluminum?
5mcg/kg/day
What is considered toxic levels of aluminum?
60mcg/kg/day
What can excess aluminum cause?
Liver disease
What patient populations are considered “High Risk” for aluminum contamination?
Renal disease
Neonates, specifically premature
Long-term PN therapy, especially ones with high aluminum content
What are the major sources of aluminum contamination?
Phosphate, Acetate, Gluconate salts
To avoid aluminum contamination should NaPhos be used or KPhos?
NaPhos because the K+ salt
Besides tapering down by 1-2 hours what else can be used to taper a patient off a PN?
Dextrose containing fluid
What size filter do you use for a 2:1 PN? 3:1?
- 22u for 2:1
1. 2u for 3:1
What are some ways to avoid catheter-related occulsions?
Dedicated line for PN Don't use incompatible meds in a Y-line Alteplase for thrombus Ethanol for lipid build-up HCl or cysteine for Ca/Phos
Can you give calcium, phosphate, or magnesium salts via Y-site with PN therapy?
No. Ca, Phos, and Mg salts cannot be given via Y-site with PN therapy.
What are some drugs that are incompatible with both 2:1 and 3:1 PNs?
Midazolam
Phenytoin
Sodium Bicarbonate
What are some drugs incompatible with 3:1 PNs?
Heparin
Iron dextran
Hydromorphone
What are some drugs incompatible with 2:1 PNs?
Some lipid soluble medications
_____ drips may be co-infused if venous access is limited.
Insulin
What interaction can cause life threatening IV or pulmonary issues?
Calcium and ceftriaxone precipitation.
What patient population is a PN containing calcium and someone getting IV ceftriaxone contraindicated?
Neonatals
If you were going to sequentially administer Ca and ceftriaxone what must you do?
Flush the line
What are some options to prevent DNI with ceftriaxone administration?
When initiating PN with patient on ceftriaxone withhold calcium from PN for 48 hours after last ceftriaxone dose. (not a good option for neonates needing calcium)
You can also use cefotaxime instead of ceftriaxone.
What type of DNI occurs with feeding tubes and feeding formulas?
Type I
When giving hypertonic/hyperosmolar medications into the small bowel what is a way to prevent DNI adverse effects?
Dilute with 10-30mL of sterile water.
When changing medication to a liquid dosage form what form is preferred?
Elixir and suspension is favored over a syrup.
If there is gastric distress what must you check when turning a medication into a liquid for enteral administration?
Sorbitol content
What do you do before and after administration of an enteral medication?
Flush the tubes
When administering drugs what must you do between each medication?
Flush
Can you add drug to an enteral nutrition formula?
No