Drug Screening Tests
Non-Opioid medications prescribed as an analgesics are non-steroidal anti-inflammatory drugs (NSAIDs), anti-epileptics and anti-depressants. Most effective analgesic available to relieve severe intractable pain is opioid. Opioid is a jewel of analgesics and effective in severe pain caused by cancer and non-cancer diseases. Opioid is sold on the street as heroin. Heroin is retailed on street and consumed by adults of all ages. Addict, to prevent withdrawal symptoms, uses heroin as recreational drug in the beginning and later frequently. Heroin is either inhaled or injected for rapid effects. Cost of heroin is substantial; and heroin addict are often bankrupt and not employed. Alternatively individual may try to replace heroin with prescription opioids. Prescription opioids like morphine; oxycodone, hydrocodone and fentanyl are often used as replacement to heroin.
Opioids are prescribed to patient who are suffering with severe intractable pain and not responding to nonopioid pain medications. Prescription opioids are necessary for these patients to maintain customary activities. Cost of prescription medication is paid or reimbursed by insurance companies. License physician in United States prescribes opioid medication for chronic pain. Drug addict becomes drug seeking patient as cost of street drug is agonizing and unbearable. Drug seeking patient pretends to be pain patient and gets opioid prescription from physician to use for recreation. Drug seeking patients often have financial difficulties and need cash to support other illegal habits. Need for additional cash may influence drug seeker to trade part of the prescribed opioids on the street or may share these medications with friends and family.
Opioid Drug Seeker:
Opioid drug seeking patients cause additional cost to insurance companies and spread addiction among their relatives and friend by sharing medication. Patient may visit several doctors or more than one doctor to get opioid prescription known as doctor shopping. Doctor shopping results in possessions of large number of opioid pills, which are sold for substantial cash. Drug seeking behavior of opioid addict results in doctor shopping, illegal trade of opioid medications on the street, illegal distribution of opioid among friends and relatives. Physician communities are aware of patients malingering to get the opioid prescription. Primary care physician and physicians treating pain patients are actively involved in opioid screening to differentiate legitimate and genuine use of opioid for chronic pain and discourage drug seekers.
Opioid Screening Involves:
- Substance Abuse
- Legal Problems
- Medication Craving
- Heavy Smoking
- Mood Swings
Opioid Screening Tool:
Opioid screening tools consists of several questions based of psychology, social behavior and history of drug abuse. Screening tools used for evaluation of patient using opioid is as follows :
- Screening tool for additional risk (STAR).
- Drug abuse screening test.
- Screener and Opioid assessment for patient with pain (SOAPP).
- Pain assessment and documentation tool (PADT).
- Opioid Risk Tool (ORT).
- CAGE questionnaire.
- Prescription opiate.
- Prescription Drug Use Questionnaire (PDUQ).
- Substance Use Questionnaire (40-42).
Opioid Screening tools are used for screening patients who may need opioid for chronic pain. Opioid Screening test is used to evaluate risk for aberrant use of opioid medications. Opioid Screening test at times has limited use because of significant amount of time needed to complete test and also analyze answers. The Opioid screening tool is meant to evaluate the intensity of pain, opioid use in the past, social stimulus, family influence, history of substance abuse, prior treatment in a drug rehabilitation facility, nicotine use, self-assessment of excessive nicotine use, treatment in another pain clinic and psychiatric history. Test may predict addictive disorder or tendency. Screening test consistency, reliability and predictability is questionable if patient does not understand the questions because answers could be inappropriate. Scores may divide patient into two groups low risk and high risk. Further interview, history and examination are necessary before considering patient in high risk group for opioid treatment. The screening tools are studied to evaluate efficacy but none of the study validate predictive aberrant use of opioids.
Some of the study may help to identify prescription opiate abuser. Test results indicating presence of 3 or more following criteria may suggest likely drug seeker.
- Frequent request for early refills at each visit.
- Frequent multiple phone call for early refills.
- Frequent complaint of loss of medications. Excuses are pills spilled, lost or stolen.
- Doctor shopping - visiting multiple physicians for medications.
- Overwhelming focus on opioid treatment and rejecting any other treatment if suggested.
Study by Atluri and Sudarshan:
Tools developed by Atluri and Sudarshan is most useful in evaluating addiction behavior. The screening test was developed with the particular intent for use in interventional pain management settings. Urine drug test will follow to evaluate inappropriate drug use. Presence of illicit drugs, opioids other than those prescribed, refusal to provide urine samples for drug testing and any evidence of tampering with the urine specimen indicate possible association of drug addiction or abuse. Test identifies six clinical criteria as predictive factors for opioid misuse:
- Focus on opioids.
- Opioid overuse.
- Other substance use.
- Nonfunctional status.
- Unclear etiology of pain and
- Exaggeration of pain.
Study by Manchikanti and Colleague:
Manchikanti and his colleague evaluated these criteria's described by Atluri and Sudarshan in 500 patients. Outcome of study showed addiction behavior was indicative of excessive opioid needs, deception to obtain, and prior intentional doctor shopping. Findings were 90% accurate in identifying/predicting drug abuser (with odds ratios greater than 100, and p values of 0.001 or less). Thus, it was concluded that this tool provides a simple, reliable, and cost-effective means of screening for drug abuse during the clinical evaluation of patients in interventional pain management settings.
Manchikanti and colleague had conducted two other studies using test suggested by Alturi and Sudarshan. Outcome of these studies indicate illicit drug use was observed in-patient with history of current or prior use of illicit drugs. Study performed by Manchikanti and Chabal et al concluded risk of opiate abuse cannot be predicted from history of past opiate or alcohol abuse, recurring need for opiates, level of pain intensity, clinic frequent visit and presence of depressive symptoms.
Some of the following symptoms may be observed in opioid dependent patient as well as opioid addict. Patient is considered opioid dependent if higher therapeutic dosage of opioid is necessary to achieve optimum pain relief. Tolerance and resistance to opioid develops over time. Chronic pain patient relies on opioid to feel less painful. Inadequate pain relief with same dosage or ineffective generic pills urges to consume additional supplementary pills as and when needed to achieve optimum pain relief. Further history and investigation is indicated if following history follows to differentiate patient suffering with either drug dependence or addiction.
- Refuses non-opioid treatment, suggest pain relief is achieved only with opioids.
- Cannot tolerate most non-opioid medications.
- Request particular opioids and dosage.
- Frequent non-schedule office visit.
- History of other drugs and alcohol abuse to enhance pain relief.
- Pill count test indicate, often short of medications.
- Withdrawal symptoms are seen during clinic visits
Addiction is Suspected:
- History of selling prescription medication to friend, relatives or on the street.
- Forgery of prescription.
- Stealing medications from relatives, friends or pharmacy.
- Illegal consumption or possession of street drug such as cocaine or heroin.
- Daily consumption of alcohol or history of alcohol intoxication.
- Doctor shopping to acquire multiple opioid prescriptions.
- Multiple episode of prescription loss.
- Multiple attempt and request to escalate opioid dose in short period of time.
- Multiple episode of loss of medications.
- Multiple ER visit.
- Unable to go to work, recent loss of job, unable to keep job more than few weeks.
- Resistance to change medication to different opioids or non opioids.
Urine Drug Testing:
Urine opioid analysis is non-invasive analysis of urine. Urine opioid test is used to find opioids in urine. Test is to evaluate compliance, misuse or abuse of opioids. Test specificity is limited and result could be false positive or false negative. Urine drug test are done to detect opioid, which was prescribed for chronic pain. Urine analysis may detect opioid or illicit drug, which was not prescribed. Presence of prescribed opioid indicates patient is compliant with treatment plan and taking medications as prescribed. Presence of Illicit opioid in urine suggests patient is involved in using street and illicit drug.
Urine opioid screening is an immunoassay test involving competitive binding of antibodies to opioids molecules. Antibodies are opioid specific and detect the presence of a particular drug or metabolite in a urine sample. Immunoassay drug testing is done in office setting or in the laboratories. Various test kit are available depending on assay's cut-off concentration. The drawback of the test is concentration of drug above the cut-off is deemed to be positive, and any response below the cut-off is negative. Test is less sensitive when tested for semisynthetic opioids such as oxycodone, fentanyl, methadone and buprenorphine. Problem with immunoassay is cross reactivity and low specificity. Poppy seeds, chlorpromazine, rifampin and dextromethorphan may cross react with opioid reacting antibodies. If patient has consumed any of these medications opioid screening test will come positive even if patient has not taken opioid as prescribed. Similarly cross positive test results are seen with immunoassay of cannabinoids, amphetamine, PCP, Benzodiazepam and methadone. See following table-
Medication Cross Reaction in Immunoassay Study:
Cannabinoids: NSAIDs and Protonix.
Amphetamine: Ephedrine, methylphenidate, trazodone, buprepioin, Desipramine and ranitidine.
PCP: Chlorpromazine, thioridazine, meperidine, dextromethorphan and Diphenylhydramine.
Benzodiazepine: Oxaprozine (daypro) and lethal herbal agents. Methadone Propoxyphene and Seroquel.
Chromatography Urine Test:
Reliable urine test for specific opioids in urine is gas chromatography/mass spectrometry (GC/ MS). Questionable and uncertain opioid findings of immunoassay must be confirmed by chromatography test to prevent denial of patient's treatment. Immunoassay and chromatography testing is regulated by federal guideline. Non regulated immunoassay are performed for urine screening for legal purpose by worker's comp, child custody cases, drivers' license revocation, criminal justice, insurance purposes, ports testing, and pre-employment work place testing.
Immunoassay using point of contact dipstick can be performed in physician's office. Clinical Laboratory Investigative Association (CLIA) guidelines are for laboratory testing. A CLIA waiver is required to perform urine immunoassay test in physician office. Only immunoassay tests for certain drugs are CLIA waived, and these may be performed in the office only if (and when) a certificate of waiver is first obtained by the physician. Generally these tests do not require extensive training for office personnel. Unfortunately however, Medicare and other payers do not uniformly allow all CLIA-waived testing, and it becomes incumbent upon physicians to determine which tests patients' insurance programs will cover.