Learning Lab values – key points

The deeper your knowledge is about these aspects, the more value you will have in your offices.

Keep studying and memorizing.  Knowledge of these aspects is not something many reps have.

Start learning about lab values that are important to you and the patients prescribed your product with three things:

1. Go to a local medical diagnostic lab and obtain a Diagnostic Lab Results sheet with the ranges of values, High and Low, for all of their blood and urine chemistries. – These will vary a little between laboratories depending upon the types of tests they run, though the ranges should be very similar.   Most important, the lab sheet will note which test results are high or low.
2. Go to your package insert and learn how your product is eliminated from patients’ bodies. There are two main routes – Renal/kidneys and Hepatic/liver.
3. Go to your competitions’ package inserts and see if their products have similar routes of elimination to yours.

With any luck, your product will have a different elimination route than your main competition.  For example, if your product route is hepatic and the competition is renally excreted, you can learn the value ranges for kidney (creatinine clearance) versus your liver route (hepatic enzymes) which measures the liver enzymes that metabolize some drugs.  Thus, a patient’s analysis may show they have developed poor renal clearance so those patients would be strong candidates for your product.

The reason is that with a compromised elimination route, the dosage must be lowered because the half-life of the drug will be prolonged.  This could result in a buildup of the drug in the body above therapeutic range, if doses are taken before the previous one has been eliminated.  The choice then is to go to a smaller dose or less frequent dose, or switch to your hepatic route product.  It is not highly likely that patients will have reduced clearance for both routes out of their bodies.

Route of elimination are a good aspect to discuss with NP’s, PA’s, or MD’s, to find out what test ranges they consider important enough to either alter dosing regimen or change products.  Ask what liver enzyme test they find most helpful to evaluate the chance of longer half-lives.

We have seen situations where there was no alternative Rx choice, and the dosing regimen had to be shifted from twice a day (=B.I.D.) to one every other day, (=1 Q. 48h) resulting in the same blood level as before, due to the vastly increased half-life.

There are deeper levels to learn in your pursuit of being actually helpful!  Some products metabolize into an active metabolite that may have a different elimination rate!

We would love to hear your feedback!  Email us at:  [email protected]