90 day money-back guarantee
Lab order in minutes
Save a trip to the doctor
Low prices since 2005
Labs within 2 miles
Private, accurate & secure
90 day money-back guarantee
Lab order in minutes
Save a trip to the doctor
Low prices since 2005
Labs within 2 miles
Private, accurate & secure
Private MD Labs logo
Always private
Need help? Text 754-799-7833

Match your medication to the measurement you follow

Each of these answers a different medication question — which drug, and which form of it.

Therapeutic drug monitoring tests measure the amount of selected medicines or medicine-related compounds in blood, including lithium, tacrolimus, sirolimus, carbamazepine, and valproic acid. Shoppers often compare these options when a prescriber wants to follow a known medication level, distinguish total from free drug, or assess carbamazepine alongside its 10,11-epoxide metabolite. The useful next step is to match the ordered test to the medication name and the specific measurement requested, then review the result with the professional managing that medication.

Match the reported form to the clinical question

A total drug result reflects the overall amount measured in the sample, while a free result refers to the unbound portion named by the test. That distinction is built into Valproic Acid, Total and Free and Carbamazepine and Metabolite, Free/Bound/Total. For carbamazepine, the latter also reports bound carbamazepine and carbamazepine-10,11-epoxide, a named metabolite. A request for Carbamazepine, Total answers a different measurement question than an order that includes free, bound, total, and metabolite values. Use the wording on the laboratory order to select the same form of measurement requested by the clinician overseeing care.

Why timing and professional review matter

Medication concentrations are interpreted against the dose schedule, the timing of the blood draw, the reason for monitoring, and prior results. A number alone does not establish whether treatment is appropriate or explain symptoms. Lithium, Tacrolimus, Highly Sensitive, LC/MS/MS, and Sirolimus, LC/MS/MS each measure the specifically named medication, whereas Tacrolimus and Sirolimus, LC/MS/MS measures both named medications together. Record when the sample was collected in relation to the medication schedule if your care team asks for that information. Contact the professional managing the medication for interpretation, especially if symptoms or an unexpected result are involved.

Therapeutic Drug Monitoring FAQ

Therapeutic drug monitoring measures a specified medication concentration in blood to help follow an established treatment plan. Available tests include Lithium, Tacrolimus, Highly Sensitive, LC/MS/MS, Sirolimus, LC/MS/MS, carbamazepine measurements, and valproic acid measurements. Results are considered alongside dose timing, prior levels, symptoms, and the clinician’s intended target.

No. The Lithium test measures lithium in the sample; it does not diagnose a mental health condition or determine treatment by itself. Its value is generally interpreted with the medication schedule and the reason the level was requested. A clinician who knows the treatment history should assess an unexpected level or symptoms.

Valproic Acid, Total and Free reports both the total amount and the free amount of valproic acid. These are separate reported forms, so it suits an order that specifically requests both values rather than total alone. The relationship between the two needs professional interpretation within the person’s medication history and collection timing.

Carbamazepine, Total reports total carbamazepine, while Carbamazepine and Metabolite, Free/Bound/Total reports free, bound, and total carbamazepine plus carbamazepine-10,11-epoxide. Carbamazepine-10,11-Epoxide, Serum/Plasma focuses on that named metabolite alone. Select the format that matches the requested measurement, not simply the medication name.

Carbamazepine-10,11-epoxide is a named carbamazepine metabolite measured by Carbamazepine-10,11-Epoxide, Serum/Plasma and included in Carbamazepine and Metabolite, Free/Bound/Total. Measuring it separately from, or alongside, carbamazepine helps address a request that specifically names the metabolite. It does not independently diagnose a medication-related problem.

Tacrolimus and Sirolimus, LC/MS/MS measures both tacrolimus and sirolimus in one order. Tacrolimus, Highly Sensitive, LC/MS/MS measures tacrolimus, and Sirolimus, LC/MS/MS measures sirolimus when only one named medication is requested. The medication list and laboratory order determine whether a combined or single-medication measurement fits.

The timing of the blood draw relative to medication dosing can affect how a medication level is interpreted. Prior results, the reason for monitoring, and symptoms also matter when reviewing lithium, tacrolimus, sirolimus, carbamazepine, or valproic acid values. Do not use a result alone to make medication changes; seek professional review.

No. Therapeutic drug monitoring measures named prescribed or managed medications, such as lithium, tacrolimus, carbamazepine, or valproic acid, to support medication-level follow-up. Drug screening has a different purpose: it looks for exposure to selected substances. The test name should match the medication and measurement requested.

Ordering & Results FAQ

You'll receive it via email within 60 seconds of your order unless it requires additional processing (only very complex orders do).

Many general wellness test results are typically available online within 2-3 business days. However, some tests will require additional processing time. You will immediately receive an email & SMS notification when your results are available.

We do not share your results with your physician, insurance company, or any other third party.

Blood test labs by state

A C D F G I K L M N O P S T U V W