Urine Drug Testing Methadone 101 Methadone for hospitalists

Transcription

1 Urine Drug Testing Methadone 101 Methadone for hospitalists Dr. Patricia Mark MB, BCh

2 LEARNING OBJECTIVES Clarify the purpose of urine drug testing Distinguish between UDT for detection of illicit drug use and monitoring adherence to treatment plan Describe practicalities of UDT Understand the interpretation of UDT results Understand limitation of UDT

3 Basics Urine drug testing must always be discussed with patients ahead of time. It is part of the physician/ patient agreement which all patients on MMP sign. All patients must be treated the same way, and always with respect. UDT is not a means of punishing rather, it is a tool to help best management.

4 BACKGROUND FOR UDT Urine is the best biologic specimen for detecting certain drugs. Longer window of detection for most drugs. No standard test for all drugs, so screening may be a misnomer, hence the title Urine Drug Testing. Must be used in context of detailed history of all medications. Must be undertaken in a respectful way and honest way.

5 Why? To ensure that prescribers can help and support MMP patients to begin recovery and achieve stability. Provides objective evidence of compliance with the treatment plan Are patients taking medications as prescribed? Are patients using illicit substances? Adjust treatment plans if necessary to work towards best outcomes for patients on opioids for opioid addiction or chronic pain.

6 Why? UDT is only one of several ways in which physicians can assess patients stability. Careful history taking Frequent reassessment Contact with pharmacist Collateral information

7 Value of self-reporting of noncompliance Can be significantly unreliable in patients suffering from addiction disorders. If UDT is found to be discordant with history of medications: Review medical records Review PharmaNet Collateral information from significant others

8 How? Enzyme Immunoassay (EIA) Specific anti-drug antibody added to urine. If that drug is present, antibody binds to drug giving a measurable indicator reaction as positive. MMP protocol tests for: methadone metabolite opiates cocaine benzodiazepine methamphetamine oxycodone

9 How? Gas chromatography Mass spectroscopy GC separates and quantifies drug components. MS specifically identifies them. Gold standard of urine toxicology but expensive Each test is about $40 Should be used for clarification where there is a question about drug identification on EIA

10 UDT - How? Supervised: Patients remove bulky clothing, leave bags with staff, specimen is temperature tested before being sent to lab for appropriately ordered test or for POC testing. Witnessed: Patient witnessed while producing specimen. Less commonly used as can be seen to be intrusive and demeaning. May at times be necessary.

11 WASHROOMS & STANDARDS FOR UDT COLLECTION Should be on the methadone clinic or FP office premises. Hot water should be turned off. Lab tech or staff member should have immediate access to UDT specimen for temperature strip check. If unusually pale, this should be noted or specific gravity checked. If specimen does not meet temperature requirements, the patient should be requested to produce another specimen. No prescription until UDT done.

12 When? May be collected at every clinic visit may not necessarily be tested. Random samples collected at varying intervals every 3 or 4 months and tested. Random UDT is preferable and more valuable and should be used for all patients with methadone carries.

13 Which opiates show up in UDT? Metabolites of: Heroin Morphine Codeine shows as morphine which is a metabolite of codeine Reliably detected on regular EIA testing

14 UDT LIMITATIONS Cocaine is highly specific as the antibody reacts only to cocaine and its principle metabolite. Amphetamine/methamphetamine highly cross reactive and detects other sympathomimetic amines e.g. ephedrine & pseudoephedrine. Opiate testing does not distinguish between morphine, heroin and codeine. Does not always detect semi-synthetics e.g. hydromorphone. Oxycodone needs its own specific antibody. Methadone & buprenorphine also need specific antibody.

15 Drugs of interest to methadone prescribers: oxycodone Is a semi-synthetic opioid, shows up in only about 10% positive tests. There is a specific EIA for oxycodone that is reliable & is included in POC test kits. Problems associated with oxycodone screening include false negatives for patients for whom oxycodone has been prescribed.

16 Other synthetic opioids: fentanyl Wholly synthetic and does not react with EIA morphine antibody. Needs either a specific EIA or GCMS to confirm presence or absence. Patients who are on fentanyl and show positive for opiates WHICH IS NOT POSSIBLE using standard tests are abusing other opioids which react with the standard EIA testing.

17 Methadone Is a wholly synthetic opioid which does not show up on standard testing. Needs a specific EIA for methadone metabolites which is virtually 100% sensitive. All UDS kits, whether point-of-care testing or in labs, use the specific EIA for methadone metabolites to eliminate possibility of adulteration with methadone.

18 Hydromorphone Is a semi-synthetic opioid which may or may not show up on routine UDS with standard opioid EIA testing but more likely to show up if very high dosing Will require GCMS or specific EIA to confirm presence or absence

19 Buprenorphine Is a semi-synthetic morphine-based molecule which has been so altered that does not show up on standard opioid EIA testing Specific and highly reliable EIA tests available in labs and in point-of-care test kits Is now becoming more widely prescribed and there is a specific simple dip stick test which can be used

20 Benzodiazepines Always monitored by UDT, as are contraindicated for patients on the MMP. EIA for benzos is based on the diazepam antibody. Shows reliably positive test for diazepam and alprazolam. Most diazepam EIAs do not detect clonazepam or lorazepam. GCMS may be needed to identify both these benzos.

21 POC TESTING POC testing now commercially available, simple to perform and gives rapid information while patient is in the office Several companies are involved in production Is covered by MSP Uses immunoassay methods with all the advantages and disadvantages

22 POC TESTING MMP Protocol POC also tests for: Methadone metabolites Opiates Cocaine Benzodiazepines Amphetamine Oxycodone

23 Urine detection time frame Methadone 4 5 days Opiates 2 3 days Cocaine/metabolites 2 4 days Benzodiazepines 1 42 days THC single use 2 3 days THC habitual use up to 12 weeks Methamphetamine 3 5 days Alcohol 6 24 hours

24 UDT interpretation What shows in UDT is important. What does NOT show in UDT is equally important: Methadone metabolites if methadone prescribed Benzos especially clonazepam Synthetic and semi-synthetic opioids Beware of very dilute urine, may be an attempt to dilute out drug metabolites. PharmaNet essential to confirm what patients should be taking if prescribed. Results should always be reviewed with the patient.

25 Limitations of UDT Assesses the presence or absence of a particular drug and/or metabolite at a specific threshold of concentration at a specific time. Unexpected result does not diagnose Abuse or addiction Physical dependence Diversion. Does not provide accurate information on Time of last use Amount and frequency of use.

26 Potential harms of UDT Incorrect interpretation of UDT could result in: Unwarranted discontinuation of opioids Damage to physician/patient relationship If very unexpected result, especially with POC testing, always get laboratory confirmation Potential for false reassurance Adulteration/cheating Alteration of behaviour in anticipation of UDT, hence need for random UDS

27 Consequences of positive urine drug tests Always review results of UDT with patient UDT result is one of many factors taken into account when making clinical decisions Review physician/patient agreement Review treatment plan Increase frequency of office visits Methadone dose if opiate positive: is it appropriate? May have to discontinue carries in the face of instability Increase counselling and other support services

28 ADDICTION BASICS FOR HOSPTIALISTS When opiate dependent patients admitted: If possible, collateral information from family, friends or family physician If necessary, talk to the pharmacist PharmaNet Previous medical records Urine drug testing on admission and serially as necessary thereafter Appropriate blood work on admission

29 METHADONE ESSENTIALS FOR HOSPITALISTS Drug addicted patients needing medical care are frequently admitted under hospitalists Can be challenging and disruptive Self-reporting usually not reliable UDT is objective evidence which will help to make treatment planning more effective

30 UDT IN HOSPITAL Most hospital labs look for a number of other drugs as they are geared more for drug overdose investigations. Some labs do not look for methadone metabolites. MRPs can request the MMP protocol which some hospitals will do.

31 Polydrug use Most patients with addictions disorders are polydrug users. Very few stick to one drug of choice. Important to consider all possibilities when ordering UDT. UDT may be very informative about prescribed medication not being taken. Collateral history and PharmaNet very helpful as many abused drugs are now prescription drugs.

32 INTERPRETATION OF UDT UDT results should always be reviewed with the patient If the patient is on opiates as confirmed by PharmaNet and UDT, will have to be supported in hospital to prevent withdrawal Opiate withdrawal is unpleasant but unlike alcohol withdrawal is not dangerous Patients in hospital are likely to leave AMA if not supported to prevent withdrawal Opiate dependent patients may be suitable candidates for the MMP and may be initiated while in hospital

33 Treatment planning While in hospital should include: addictions consult if possible mental health assessment as many addicted patients suffer from concurrent mental ill health discussion about opioid substitution for opiate dependant patients: omethadone osuboxone Patients initiated on to methadone or suboxone must have community prescriber available to continue prescribing after discharge

34 Conclusion Urine drug testing is an important part of the comprehensive care of patients who are on MMP or are receiving opioids for chronic pain and must be undertaken in a respectful, nonjudgmental manner. Should be considered as an objective test within the greater biopsychosocial context. Should always be interpreted in the context of broad based clinical care of the individual patient.

35 And remember This is a difficult patient population Most of them have had terrible lives They are accustomed to being treated without respect Requesting UDT can seem like an insult although on the street all opiate dependent patients know that UDT is part of treatment The way we treat our addicted patients may make a huge difference in their lives We have the power to make that difference

36 UDT for methadone prescribers Thank you