Saliva testing is a diagnostic technique that involves laboratory analysis of saliva to identify markers of endocrine, immunologic, inflammatory, infectious, and. Saliva testing is used for measuring hormones like cortisol, estrogen and testosterone, and its non-invasive collection asks patients to spit into a plastic tube. THC (marijuana) screening in saliva. No saliva manipulation. Results in mn. Reliable, easy and fast.
Other drugs include the sedating antihistamines, antipsychotic drugs, anticholinergic drugs and a number of antidepressants. There are less commonly used drugs that increase flow and these include clonidine, pilocarpine and beta-2 stimulants salbutamol, terbutaline etc.
Consequently, there is significant intra- and inter-subject variation in relation to drug concentrations depending on the technique used, the physiology of the person and the influence of factors affecting drug concentration in oral fluid. Since the collection of oral fluid specimen can be viewed by a second person without infringing privacy it does not suffer from the same issues regarding possible adulteration or substitution as for urine.
The prior administration of drugs and a range of physiological factors covered earlier can affect drug concentration. In an early study using a small number of volunteers, the consumption of beer immediately smoking a marijuana joint appeared to lower concentrations of THC in oral fluid at 1 h post dose.
Since the oral fluid in the mouth is rapidly turned over, a wait of several minutes should allow re-equilibration of drug in the surrounding tissues. The rinsing effect with drugs is in some way similar to the contamination of breath alcohol by recently consumed alcohol in that a wait of 15—20 min allows any mouth alcohol to be removed by normal physiological processes. There is no one type of collection device that is clearly superior based on design or ease of use.
However, recovery studies conducted on some devices suggest that desorption of drugs may limit the usability of some collection materials. Clearly more information is required for all drugs likely to be measured in oral fluid, for each collection device. Indeed a device should not be used until recovery and stability studies have been performed and show adequate performance.
However, it should be emphasised that products are continually being developed and hence published results on an earlier design may not bear any resemblance to more recent designs. The use of oral fluid to detect drugs has potentially wide applications. To date its main application has been to provide a non-invasive specimen for testing of possible drug-affected drivers. Oral fluid should not be seen as a specimen that replaces the use of other specimens.
As discussed later the pharmacokinetic characteristics of drugs are more closely aligned to blood concentrations than, for example, urine or hair. Urine should still be seen as the specimen of choice if evidence of prior exposure to drugs of abuse is sought eg routine workplace screening without cause and drug screening of prisoners. Hair will still be much more useful if a longer time frame of exposure to drugs is sought.
However, if evidence of recent use or abstinence of drugs is sought then either blood or oral fluid are preferred specimens. Oral fluid has the advantage over blood in that it can be obtained non-invasively in a situation where adulteration or substitution is difficult.
A review of the advantages and disadvantages of specimens is available. A recent review of the pharmacokinetics of some drugs in oral fluid has been published. For example, there is almost no carboxy metabolite of THC present in oral fluid. However, due to the rapid bioconversion of cocaine, benzoylecgonine and ecgonine methyl ester they are also detectable in oral fluid. In the case of most drugs the oral fluid concentration can be estimated from the pH of oral fluid and blood, the protein binding of the drug and its pKa.
The average concentration ratio is shown in Table 2. In the absorptive phase there are often higher concentrations in the oral fluid due to local absorption in the mucous membranes of the buccal cavity. This local absorption effect is probably highest for THC due to its higher fat solubility and ease of penetration through membranes and the very low partitioning from blood to oral fluid. However, as discussed later in this section this effect is also seen for other drugs.
Type refers to physiochemical property of drug, ie acidity, basicity or neutrality. The average ratios are indicative figures derived from pharmacokinetic studies and will change depending on a number of factors, including pH of oral fluid, protein binding and degree of contamination of the membranes in the oral cavity by recently consumed drug.
The most commonly detected drug toxicologically, alcohol ethanol , has been subject to much research in terms of its presence in oral fluid. The oral fluid to plasma concentration is similar to that predicted based on the water content of the two fluids and averages just over unity and has been used to assess alcohol exposure. Subjective intoxication and the increase in heart rate in volunteers taking cannabis correlated well with oral fluid THC concentrations.
The administration of 30 mg doses of codeine phosphate showed a good correlation of plasma and oral fluid concentrations particularly after 2 h following the initial contamination of the oral cavity. Some concordance of the physiologic and subjective effects of codeine and oral fluid concentration occurred following single oral codeine doses to volunteers. Orally administered morphine shows a delay in the appearance in oral fluid compared to its presence in plasma suggesting some rate limiting movement in oral fluid possibly due to its relatively low lipid solubility.
Buprenorphine is widely used for the treatment of opioid dependency and is available amongst other formulations as a sublingual tablet. In the terminal phase of elimination oral fluid concentrations were similar to plasma.
A similar depot effect occurs with nicotine. Research suggests that measurement of the major metabolite cotinine is more useful than nicotine to determine exposure to this drug. Slow equilibration between plasma and oral fluid has also been observed for diazepam. Mean oral fluid to plasma ratios for diazepam are about 0. These data show that the pharmacokinetics of drugs in oral fluid is more complex than that of blood. Detection times in this specimen will depend on a range of factors including dose, frequency of use ie acute versus chronic use and detection limits of analytical assays.
A number of other drugs of forensic interest have been measured in oral fluid. These include hydromorphone, 47 phencyclidine, 48 pholcodine, 49 and sildenafil. TDM of drugs in oral fluid has been studied for at least 30 years although it has been increasingly used in a range of applications. There is some support for its routine application for some anticonvulsants and theophylline. Other clinical applications include testing for HIVantibodies, 58 , 59 and a number of steroids including cortisol and dehydroepiandrosterone, 60 and hydroxy progesterone.
However, care will be needed to avoid changes in concentration in oral fluid caused by a variety of factors discussed elsewhere in this review. Initial testing of oral fluid for drugs can either occur in the field other words for this form of testing include on-site or point-of-care testing or in the laboratory. A number of devices are available for field use. These are optical readers that provide a visual readout of intensity of response of the immunoassay signal.
Unfortunately, there is no consistency in the specifications applied to these devices. For some, cut-off concentrations are used to define their detectability, for others concentrations are given when drugs can be detected. The apparent sensitivity is often not defined in terms of consistency of detection in oral fluid specimens.
This means that at the present moment there is no objective way to assess performance of these devices or cartridges. In the laboratory, terms such as false positive FP and false negative FN are used.
FP refers to a situation when a presumptive initial test result is not confirmed. FN refers to a situation when a confirmation test finds a drug present that was not detected by the initial test. Sensitivity is often used in defining performance of initial testing kits and refers to the relative detectability of the kit or device of positive cases in question over a comparison method. On the other hand, specificity refers to the percentage of negative results using the kit or device compared to the total number of negative specimens using a comparison method.
A number of published studies have evaluated devices either using fortified oral fluid with known drug concentrations or real specimens taken from humans exposed to the drug under question.
Detection times ranged up to 10 h postdose although it was most reliable to 6 h. A recent study in Victoria, Australia in which over 13, motorists were randomly screened for presence of methamphetamines methamphetamine and MDMA and THC as part of a campaign to reduce drug affected driving found a positive rate of 1: The overall FP rate using both devices was very low one cannabis and four methamphetamines. As for urine, immunoassay tests of a drug class will not detect all members of the drug class equally.
For example, the required sensitivities of the initial test for the amphetamine, opiate and benzodiazepine classes will be different for the various drugs since the concentration of drugs in these classes are quite different to that of blood. For example, amphetamines have higher concentrations in oral fluid compared to blood and benzodiazepines have concentrations only a fraction of those in blood.
Hence, it is important that the selection of on-site testing devices has the appropriate sensitivity and indeed other performance characteristics for the intended applications. There are a number of commercial kits based on ELISA technology available for laboratory screening of oral fluids. These generally work satisfactorily for amphetamines, 68 , 69 buprenorphine, 70 cocaine, 65 , 71 — 73 methadone, 74 and other opioids, 72 , 75 , 76 and provide a reliable means to screen oral fluid.
Cannabis can be more difficult particularly if the immunoassay has little cross-reactivity to THC. Nevertheless enzyme immunoassay has been successfully used for this drug. The power of MS has been used as a screening system for a range of drugs. Given the larger water component and lower protein content of oral fluid compared to blood, recovery of drugs is not usually a limiting factor.
The smaller sample volume and often lower concentrations in oral fluid require the most adjustments to analytical techniques. The required detection or quantification limit for drugs in oral fluid depend very much on the application and type of screening test employed.
The variable target minimum concentrations probably reflect the relative embryonic stage of drug testing compared to urine drugs of abuse testing. It is possible that some international agreement may exist in the future regarding minimum detectable concentrations or cut-offs.
However, this is unlikely since there are still significant differences in cutoffs in urine between countries after over 30 years of testing. Moreover, inadvertent exposure may limit the concentrations that can be used to prove deliberate use.
Nevertheless, numerous papers exist that provide validated methods for the detection of notable drugs in oral fluid. A summary of these is shown in Table 4. Predominantly, the preferred technique is MS due to its high sensitivity and specificity. Consequently the focus is on the use of this technique. Detection limits are within or less than those mentioned in Table 3 and use volumes of oral fluid from 0. A review of the pros and cons of LC-MS methods in oral fluid drug detection has been published.
Whatever technique is used it is important that the detection limits applied to confirmation testing is the same, but preferably lower, than the initial testing threshold concentration. This avoids not being able to confirm an initial on-site positive result because of insufficient sensitivity and to cater for presence of some metabolites that cross-react with antibodies used in immunoassays.
Only results from those batches where performance criteria are satisfactorily met are therefore accepted. All other results are rejected and the analysis repeated. Additionally the methods used must be fully validated and comply with International harmonised guidelines. In addition, most laboratories take part in some form of proficiency test to independently assess their ability to detect drugs.
One program in oral fluid has been reported. In essence this means that there are checks and balances for using laboratory-based test kits including their calibrations and monitoring their performance. When cassettes by themselves or cassettes placed in readers are used in the testing location workplace, street, etc there is a need to ensure a level of quality assurance takes place to ensure that the devices are used as recommended by the manufacturer and sufficient quality issues have been addressed to ensure optimum and consistent performance.
This includes the training of staff, the running of suitable quality controls and participation in external proficiency tests. The principles of good laboratory practice do need to be also considered for on-site testing.
In practice this may be more difficult given that the environmental conditions and location are much less controlled than a laboratory. Nevertheless, it is imperative that the collection and testing process is as controlled as is reasonably feasible and the staff performing the collection of specimens and the testing are properly trained, otherwise it is likely that initial on-site results will be less reliable.
This may produce a higher rate of FP and FN. The last decade has seen a revolution in the development of alternative specimens for drug analysis. The use of oral fluid has been found to offer significant promise when detection of relatively recent use of drugs is sought in a non-invasive manner. Technological advances do allow on-site detection of drugs, but there are technical issues in relation to collection of oral fluid and in the variability of drug concentrations of different drug types in this fluid.
More research is needed to further the detection of drugs present in this fluid which should allow improved reliability of detection of drugs.
Similarly, future technological developments of on-site devices should allow more sensitive and reliable detection of a number of drugs. National Center for Biotechnology Information , U. Journal List Clin Biochem Rev v. Author information Copyright and License information Disclaimer. Prof Olaf Drummer e-mail: The contents of articles or advertisements in The Clinical Biochemist — Reviews are not to be construed as official statements, evaluations or endorsements by the AACB, its official bodies or its agents.
Statements of opinion in AACB publications are those of the contributors. No literary matter in The Clinical Biochemist — Reviews is to be reproduced, stored in a retrieval system or transmitted in any form by electronic or mechanical means, photocopying or recording, without permission. Requests to do so should be addressed to the Editor. ISSN — This article has been cited by other articles in PMC. Abstract Over the last decade there have been considerable developments in the use of oral fluid saliva for drug testing.
Introduction Drug testing has undergone major advances, particularly over the last 10 years. Scope of Review This paper reviews the developments and applications of drug testing in oral fluid particularly over the last 10 years. Source of Oral Fluid Oral fluid saliva is excreted primarily by three glands: Collection Techniques and Adulterants Expectoration or spitting provides neat oral fluid, but this is relatively viscous and can be dif.
Table 1 Selection of collection devices reported in literature. Open in a separate window. Recovery of Drugs from Collectors There is no one type of collection device that is clearly superior based on design or ease of use. Applications of Oral Fluid Drug Testing The use of oral fluid to detect drugs has potentially wide applications. Pharmacokinetics A recent review of the pharmacokinetics of some drugs in oral fluid has been published.
Table 2 Average oral fluid to blood concentration ratios for selected drugs. Drug type Average oral fluid to blood concentration ratio Reference Alcohol ethanol 1. Therapeutic Drug Monitoring TDM TDM of drugs in oral fluid has been studied for at least 30 years although it has been increasingly used in a range of applications. Initial Testing Techniques Initial testing of oral fluid for drugs can either occur in the field other words for this form of testing include on-site or point-of-care testing or in the laboratory.
Field Testing A number of devices are available for field use. Table 3 Recommended minimum detectable concentrations of drugs in oral fluid. Table 4 Selected mass spectrometric methods used to quantify some common drugs in oral fluid.
Conclusions The last decade has seen a revolution in the development of alternative specimens for drug analysis. Kintz P, Samyn N. Use of alternative specimens: Progress of liquid chromatography-mass spectrometry in clinical and forensic toxicology. Liquid chromatography-mass spectrometry in forensic and clinical toxicology. Liquid chromatography-mass spectrometry in forensic toxicology. Oral fluid as a diagnostic tool.
Clin Chem Lab Med. Alternative specimens for workplace drug testing. Legal issues in oral fluid testing. Detection times of drugs of abuse in blood, urine, and oral fluid.
Pharmacokinetics of illicit drugs in oral fluid. The physiology of saliva and transfer of drugs into saliva. The effects of collection methods on oral fluid codeine concentrations. Methamphetamine and amphetamine pharmacokinetics in oral fluid and plasma after controlled oral methamphetamine administration to human volunteers. Cocaine and metabolite excretion in saliva under stimulated and nonstimulated conditions. Oral fluid drug tests: The effect of blood in the oral cavity on breath alcohol analysis.
J Clin Forensic Med. Analysis of Delta9-tetrahydrocannabinol in oral fluid samples using solid-phase extraction and high-performance liquid chromatography-electrospray ionization mass spectrometry. The recovery of drugs from oral fluid collection devices.
Forensic Sci Int ;In Press. Forensic Sci Int Epub Jan 16 ahead of print. Due to its ability to provide insight into human behavior, emotions, and development, it has been used to investigate psychological phenomenon such as anxiety , depression , PTSD , and other behavioral disorders.
Salivary cortisol is a good stress index, with increased levels of cortisol correlating positively with increased levels of stress. Cortisol levels rise slowly over time and take a while to return to base level, indicating that cortisol is more associated with chronic stress levels. Because the collection of saliva samples is non-invasive, it has the advantage of not introducing further stress on the participant that may otherwise distort results. In more specific studies looking at the link between cortisol levels and psychological phenomena, it has been found that chronic stressors such as life-threatening situations example: Alpha amylase levels in saliva provide a non-invasive way to examine sympathoadrenal medullary SAM activity, which can otherwise be measured with electrophysiological equipment or blood plasma readings.
Salivary alpha amylase levels have been found to correlate with heightened autonomic nervous system activity levels, reacting in similar ways to the hormone norepinephrine. Results showed that alpha amylase levels changed when reacting to competition, but not when anticipating it. Furthermore, by testing alpha amylase levels, scientists noticed a difference in reactivity behavior among individuals with previous experience in a similar situation.
While saliva testing has the promise of becoming a valuable and more widely used tool in psychological research in the future, there are also some disadvantages to the method that must be kept in mind, including the cost of collecting and processing the samples and the reliability of the measure itself.
There is a substantial amount of both within-person and between-person variability in cortisol levels that must be taken into account when drawing conclusions from studies. Many studies have been performed to further examine the variables that contribute to these within-person and between-person variances. Analyses of the variables that affect cortisol levels has yielded an extensive list of confounding variables.
Diurnal variation is a major factor for within-person variance because baseline cortisol levels have been known to differ based on the time of day. For normally developing individuals who follow a typical day—night schedule, cortisol production peaks during the last few hours of sleep. This peak is thought to aid in preparing the body for action and stimulate the appetite upon waking.
For example, Early morning cortisol levels have been found to be elevated in shy children and late night levels elevated in depressed adolescents, particularly the between the hours of two and four PM. Other variables that affect within- and between-person variation are listed below. The list is not meant to be comprehensive and the impact of many of these variables could benefit from further research and discussion. A study examined the use of saliva testing to measure estradiol , progesterone , dehydroepiandrosterone DHEA , and testosterone levels in 2, individuals male and female.
In a study identified luteinizing hormone LH as an accurate salivary biomarker of ovulation in females. The researchers determined that salivary estradiol and progesterone curves corresponded to the daily profiles normally observed in blood, although of lesser amplitude.
In Shibayama, et al. Researchers determined that the accuracy of saliva testosterone and DHEA measurement exceeded A study by Zhang, et al. In Emekli-Alturfan, et al. Researchers found that the salivary as well as serum level of this marker was significantly higher in women with breast cancer than in healthy women and women with benign breast lesions; they went on to state that the marker may have potential as a tool for diagnosing breast cancer or detecting its recurrence.
In Jou, et al. A study compared the saliva glucose levels of diabetic patients to those of non-diabetic controls. Researchers found that sixty-five proteins, the majority of which are involved in regulating metabolism and immune response, were significantly altered in type-2 diabetics.
The first of these was published in by Zelin, et al. Several studies have demonstrated diagnostic potential for salivary hepatitis testing. A study found that saliva-based detection of the parasite Entamoeba histolytica was superior to existing fecal detection methods for patients with E.
In a study, researchers investigated the accuracy of Helicobacter pylori diagnosis in dyspeptic patients using salivary anti- H. They determined that saliva testing for H. Based on their results, researchers concluded that saliva testing could serve as a reliable non-invasive detection method for H.
A study conducted by Koss, et al. In Punyadeera, et al. Cardio-protective nitric oxide is generated in the body by a family of specific enzymes, nitric oxide synthase. An alternative pathway for the generation of nitric oxide is the nitrate-nitrite-nitric oxide pathway in which dietary inorganic nitrate is sequentially reduced to nitric oxide.
Salivary nitrite is then further chemically reduced in blood and tissue to nitric oxide resulting in the lowering of blood pressure , inhibition of platelet aggregation, increasing cerebral blood flow and flow-mediated dilation, and decreasing oxygen cost during exercise. Here, they showed ingestion of beet juice, a nitrate-rich food, by healthy volunteers markedly reduced blood pressure and by disrupting saliva, either by spitting or interrupting the bioconversion of dietary nitrate to nitrite in the mouth with anti-bacterial mouthwash, the chemical reduction of nitrate to nitrite to nitric oxide with an associated decease in blood pressure was abated.
By blocking saliva from recirculating or preventing salivary nitrate from being chemically reduced to nitrite, it prevented a rise in plasma nitrite levels, and blocked a decrease in blood pressure as well as abolished nitric oxide-mediated inhibition of platelets aggregation confirming the cardio-protective effects were attributable to nitric oxide via the conversion of nitrate to nitrite in saliva.
In a series of reports by Ahluwalia and colleagues, they showed in a cross over protocol of 14 volunteers who ingested inorganic nitrates, plasma and saliva nitrite level increased 3 hours post ingestion with a significant reduction of blood pressure. Nitrate extracted from blood by the salivary gland, accumulates in saliva, which is then reduced to nitric oxide to have a direct blood pressure lowering effect.
Decreasing saliva nitrite in volunteers that already had elevated levels, a rise in systolic and diastolic blood pressure resulted. Furthermore, pre-hypertensives may be more sensitive to the blood pressure lowering effects of the dietary nitrate-nitrite-nitric oxide pathway.
A study explored the relationship between allergies and salivary immunoglobulin levels in eighty subjects. Researchers demonstrated an association between development of allergies and disturbances in saliva allergen-specific IgA levels elevated compared to controls and total secretory IgA reduced compared to controls.
In Pink, et al. Researchers found that several drug metabolites were detected more frequently in saliva than in urine; this was true for 6-monoacetylmorphine , amphetamine , methamphetamine , and N-desmethyldiazepam.
One often cited criticism of using saliva as a diagnostic fluid is that biomarkers are present in amounts that are too low to be detected reliably. Biomarker specificity is another consideration with saliva testing, much as it is with blood or urine testing.
Many biomarkers are nonspecific for example, CRP is a nonspecific inflammatory marker , and thus they can not be used alone to diagnose any particular disease. This issue is currently being addressed through identification of multiple biomarkers that are correlative of a disease; these can then be screened concomitantly to create a comprehensive panel of tests that significantly increases diagnostic specificity.
Of note, certain types of saliva testing are considered by many to be more specific than blood testing; this is particularly true for steroid hormones. As with other diagnostic testing methods, one drawback of saliva testing is the variability that exists among diagnostic devices and laboratory analysis techniques, especially for measuring hormones. As the research community continues to validate and refine test methods and establish standard diagnostic ranges for various saliva biomarkers, this issue should be resolved.
National Institute of Health and Public Health Service each granted significant funding to further advancements in salivary testing, including the continued development of diagnostic standards.
Cortisol saliva tests (4)
Common uses for saliva are to test for the presence of disease markers, such as the BRCA breast cancer genes and for examining steroid. In the past you've discussed saliva tests and have said that they're not a reliable method of assessing hormone levels. Is this still the case or are the tests now. Saliva testing is non-invasive and designed so that the patient may collect the specimen(s) in the privacy of his or her own home. Patients are sent a test kit with .