Carbamazepine

Alternative names, keywords

Tegretol, CBZ

Samples required

● Clotted blood (gold cap, 5 mL tube), pre-dose (trough). Smaller tubes are available for paediatric samples.

Note significant diurnal variation - sampling time in relation to dose is important.

Note 14 days to steady state following start of therapy, 4 days following change of dose.

Please complete request forms with full details of the drug regime.

Test indications

Factors affecting test performance/ results

Unexpectedly high results inconsistent with clinical expectations may be seen in patients with impaired renal function, due to altered drug clearance.

As with any assay employing sheep antibodies, the possibility exists for interference by human anti-sheep antibodies in the sample, which could cause unreliable results.

In very rare cases, gammopathy, in particular type IgM (Waldenström’s macroglobulinemia), may cause unreliable results.

Results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Reference range

4 - 12 mg/L (pre-dose)
_{Source: Roche Cobas^® Carbamazepine kit insert, 2024-01 V3.0}

Turnaround time

Same day (if urgent, within 2hr at RSCH, 4hr at PRH)

Enquiries

Biochemistry (Automation)