Content - Week 6

Description:

This week's written lecture, you will read an introduction on how to interpret relevant laboratory values as well as common drug, herb, and nutrient interactions.

Purpose:

This aims to give you a framework to meet the course objectives of being able to accurately interpret laboratory values in the following case study.

What to gain:

  • Make sure you know the common drugs and nutrient/food sources that have interactions.
  • Understand how common lab values are interpreted and how they are each relevant in different disease states.

I suggest taking notes in table format to help you memorize and summarize some of these important points.

Lecture: Laboratory Data

Protein Status - 

Protein status is one of the first ways we assess for nutritional status. We judge protein status by looking at these labs:

Albumin (ALB) (3.5-5.0 g/dL)

  • A protein synthesized in the liver
  • Accounts for ~60% of total serum proteins
  • Indicator of protein deficiency
  • 3-week half-life

Prealbumin (PAB) (15-36 g/dL)

  • A more sensitive indicator of protein deficiency
  • Serum levels decrease with inflammation, malignancy, protein wasting diseases of intestines or kidneys
  • 2-day half-life

Complete Blood Count (CBC) and differential

CBC or CHEM10 is one of the most common lab panels used. Here are some highlights from your reading on the interpretations of these commonly used labs:

Serum Albumin (SER ALB) (3.4-5.4 g/dL)

  • Low w/ kidney or liver disease
  • Decreased after surgery, w/ Crohn’s, PEM

Hemoglobin (Hgb)

  • Measurement of the total concentration of Hgb in peripheral blood
  • A more direct measure of iron deficiency than Hct

Hematocrit (Hct)

  • Measurement of % RBC’s in total blood volume
  • May be decreased with malnutrition, renal disease
  • Affected by hydration status

Lipid Panel

  • Total Cholesterol (<200 mg/dL)
    • Measurement of total cholesterol in the blood
  • Triglycerides (40-60 mg/dL)
    • Requires fasting or results will be high
    • Age/sex-dependent
    • High in those with glucose intolerance (Diabetes), hyperlipidemia
  • LDL (<100 mg/dL) Low Density Lipoproteins
  • HDL (>60 mg/dL) High Density Lipoproteins

Electrolytes

  • Na+ (sodium)
    • Of general interest for pts with renal failure, DM, dehydration, etc.
  • K+ (potassium)
    • Decreased levels may be associated with diarrhea, diuretics
  • Cl- (Chloride)
    • Of general interest for pts with renal failure, DM, dehydration, etc.

Lab Values for Specific Disease States:

Diabetes Mellitus

  • Normal fasting blood glucose is between 70 -100 mg/dL
  • Dx of diabetes is made when 2 separate FBG’s >126 mg/dL
  • Impaired glucose tolerance FBG >110 mg/dL
  • HbA1C 7.0% or greater = DM

Renal Failure (CKD/ESKD)

  • Creatinine (0.5-1.2mg/dL)
    • Increased w/ renal disease and w/ PEM
  • Blood Urea Nitrogen (BUN) (5-20 mg urea N/dL)
    • Increased w/ renal disease
    • Decreased w/ pregnancy, liver failure
  • Phosphorus (3-4.5 mg/dL)
    • High levels w/ renal failure
  • Total Calcium (8.5-10.5 mg/dL)
    • High levels w/ renal failure
  • Potassium (3.5 – 5.5 mEq/L)
    • Increased w/ kidney failure, DM, K-sparing diuretics
    • Decreased w/ diarrhea, K-wasting diuretics

Common Drug, Herb, Nutrient Interactions

Class

Used to treat...

Analgesic

Pain

Antacid, Acid Blocker

Stomach upset, ulcers

Antibiotic

Infection

Anticoagulant

Blood clots

Anticonvulsant

Seizures, epilepsy

Antihistamine

Allergies

Antihyperlipidemic

High blood cholesterol

Antihypertensive

High blood pressure

Anti-inflammatory

Fever, inflammation

Antineoplastic

Cancer

Diuretic

Water retention

Laxative

Constipation

Psychotherapeutic

Depression, anxiety

Drug-Nutrient Interactions Appendix - Download Drug-Nutrient Interactions Appendix - Consider downloading to have with you as a reference. You won't be expected to know all of the interactions but you will want to have the ability to look at potential drug interactions up when reviewing cases.

Benefits of minimizing drug interactions

By minimizing drug interactions, the medications intended outcomes are more likely to happen. The patient may not have to discontinue the drug. Potentially, less caloric or nutrient supplements are needed, adverse side effects are avoided, complications minimized and fewer liability issues as a result.

Food-Drug Interactions

Foods can interfere with the stages of drug action in many ways. The most common effect is for foods to interfere with drug absorption, so then, the drug is less effective because less gets into the blood and to the site of action. Second, nutrients (or other chemicals in foods) can affect how a drug is used in the body. Third, the excretion of drugs from the body may be affected by foods, nutrients, or other substances. With some drugs, it's important to avoid taking food and medication together because the food can make the drug less effective. For other drugs, it may be good to take the drug with food to prevent stomach irritation. It is important to note that Alcohol can affect many medications and is often contraindicated with many drugs.

Let's talk about one of the most common nutrient-drug interactions: grapefruit (juice). Grapefruit juice inhibits one of the enzymes(CYP3A4) that break down certain chemicals (drugs). Bergamottin Links to an external site. and dihydroxy-bergamottin are the chemicals in grapefruit juice that inhibit this enzyme(CYP3A4), thereby resulting in increased plasma levels of any drug that is normally catabolized by CYP3A4. Meaning it can intensify the effect of certain drugs because it inhibits the metabolism of the drug. The structure of bergamottin is shown below:

structure of the chemical compound bergamottin

 

Upcoming activities:

The case study will require you to utilize this content in the context of a patient assessment.