It is well established that saliva antiepileptic drug (AED)
concentrations strongly correlate with serum concentrations.  In the
October 2005 issue of ?Therapeutic Drug Monitoring? - the Official
Journal of the International Association of Therapeutic Drug
Monitoring and Clinical Toxicology ? there is a paper published under
the title ?Stability of Salivary Concentrations of the Newer
Antiepileptic Drugs in the Postal System.?  In this document, Doctors
Jones, M; Ryan, M; Miles, M; Tang, P; Fakhoury, T; deGrauw, T; and
Baumann, R conclude that: ?Saliva collection is painless and
noninvasive, and untrained personnel can easily be taught the
collection process. Remote patients could mail saliva samples to a
laboratory for monitoring, and samples could be obtained in the
immediate postictal state to provide a "real-time" concentration.?

I am interested in measuring carbamazepine (CBZ) concentration in
saliva for therapeutic drug monitoring (TDM) in a child which requires
frequent analysis but hates been prick for blood samples more than
eating broccoli!  I am specifically seeking to find a few specialized
lab supply firms that produce and sell saliva test kits for CBZ.  As a
reference, as this is an international question, so there no need for
the kit to be FDA approved.

Get the child scanned for a 'benign brain tumour'

Medics irresponsibly use Carbamazepine (Tegretol) for other problems
than epilepsy - it is evil - I was once precribed it for a damaged
nerve.

The only other person I know who /had/ to use it died, and the autopsy
showed a massive 'benign brain tumour' - supposedly a rare cause of
epilepsy, but somehow I am very suspicious.

Frde-ga, thank you for your frank comment and suggestion. 
Fortunately, all brain scans are negative including magnetic resonance
imaging (MRI) and computerized tomography (CT.)  In my question,
carbamazepine is used to control seizures in a childhood epilepsy
diagnostics.