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CLINICALFEATURE
Table 1 Drug detection in saliva: Currently available methodolgy detects minute quantities of
the following drugs and chemicals in saliva
Therapeutic drugs
Antipyrene
Cyclosporin
Digoxin
Mathadone
Paracetamol
Quinine
Carbamazepine
Diazepam
Lithium
Oxprenolol
Phenytoin
Tolbutamide
Recreational drugs and drugs of abuse
Amphetamines
Benzodiazepines
Cocaine
Nicotine
Barbiturates
Ethanol
Marijuana
Opioids
Phencyclidine
screened the saliva again to see how often they could correctly
identify the samples from the cancer patients. The group could
identify the saliva from cancer patients in nine out of 10 samples.
Although this is a primary, exploratory study the data is exciting
and paves way to further research in the direction. Previoulsy,
Boyle et al. 34 , have shown the possible value of p53 in saliva as a
marker for squamous cell carcinoma. Interestingly, they detected
and identified tumor-specific mutations in p53 in preoperative
salivary samples of individuals suffering from head and neck
squamous cell carcinoma.
Apart from these more recent molecular studies many have
investigated the utility of proteins in saliva for the detection of
systemic, non oral, malignancies. These results indicate that,
for instance, higher levels of salivary kallikrein in patients with
malignant tumors as compared with those with benign tumors
or from healthy controls. Others have also shown that saliva
contains the cancer antigen CA 125, a glycoprotein complex
that is an often-used marker for ovarian cancer. Indeed
according to some studies salivary CA 125 assay had a better
diagnostic value than the comparable serum assay 35 .
Saliva has also been used for monitoring patient response to
chemotherapy for breast cancer or surgical treatment of the
disease. Thus Streckfus et al. 36 , studied the protein product of
the oncogene c-erbB-2, also known as HER-2/neu, and noted
that it is elevated in the saliva of women diagnosed with
breast cancer. In earlier studies, it has also been shown that
the epidermal growth factor (EGF) is higher in the saliva of
women with primary breast cancer or a recurrence of breast
cancer when compared with women without disease 37 .
The foregoing clearly illustrates the potential of salivary
diagnostics in the management of both oral and non-oral
malignancies. In particular, the salivary proteomic and mRNA
studies and those in current development 38 including
electrochemical enzyme immunoassay procedures 39 have the
greatest promise in this regard.
Hereditary Disorders
Attempts have been made by several investigators to use
saliva as a diagnostic fluid for hereditary diseases such as
cystic fibrosis (CF), celiac disease and 21-Hydroxylase
deficiency - an inherited disorder of steroidogenesis.
However, these have been met with partial success.
Drug Monitoring
Various drugs taken internally either for medicinal or
recreational purposes can appear in saliva. However, the
salivary drug concentration is influenced by the molecular and
physicochemical characteristics of the drug and its interaction
with the salivary tissues, as well as the extravascular drug
metabolism. Additionally salivary factors including the
presence of food debris, sloughed epithelial cells, and pH
determine the drug availability 40 . More improved saliva
collection methods and preservatives that maintain the
integrity have largely overcome these problems however.
Monitoring of illicit drug use by salivary detection methods
appears to be the most promising in this context. Currently,
saliva can be used to detect opioids, barbiturates,
22 Dental Asia • May / June 2008