Prepared by J. Mabbutt & C. Maynard NaMO September 2008

1. 9: Pharmacotherapies – Pain Management Prepared byJ. Mabbutt & C. MaynardNaMO September 2008

2. 9: Pharmacotherapies & Pain Management: Objectives 1. During the session, pharmacotherapies, their uses & nursing practice issues will be overviewed 2. Pain management related to the opiate pharmacotherapies will also be highlighted providing key issues for practice 3. At the end the session, nurses & midwives will have a basic understanding of the pharmacotherapies used in the drug & alcohol field & pain management issues related to these

3. 9: Pharmacotherapies for dependence and related pain management There is a range of pharmacological therapies that are effective in the treatment of alcohol, opioid & nicotine dependence in Australia All nurses, midwives, medical officers & allied health professionals need to know about these treatments, the rationale & benefits of use Pain management for opioid pharmacotherapies is often misunderstood and patients may not receive effective pain relief

4. 9: Opioid pharmacotherapiesMethadone (1) • One of the most researched treatment modalities for dependence, & an overall assessment of its effectiveness can be made with more confidence than for other treatments • It is more effective at higher daily doses (at least 60mgs) as a maintenance therapy • A synthetic opioid with a long half-life – longer acting than heroin • It is active orally as syrup, can be administered once a day under medical or nursing supervision at a clinic, or dispensed from a specified community pharmacy or hospital

5. 9: Opioid pharmacotherapiesMethadone (2) • There are criteria for admission into methadone maintenance programs • A specialist doctor or GP prescribes methadone, with the client being registered with the local relevant authority such as the health department • Methadone should be used as part of a program that includes treatment for a comorbid psychiatric disorder, & where counselling for personal problems is available • Caution needs to be observed regarding patients receiving high doses if there is concurrent alcohol or benzodiazepine dependence as there is a risk of respiratory depression

6. 9: Opioid pharmacotherapiesMethadone – Side effects (1) Short term • Related to the central nervous system depressant properties of opioids: • Constipation • Nausea/vomiting • Drop in body temperature • Bradycardia, palpitations • Hypotension

7. 9: Opioid pharmacotherapiesMethadone – Side effects (2) Long term • Weight gain • Tooth decay due to decreased oral secretions Contraindications • Kidney disease • Liver disease For further information, see Appendix 7: Drug interactions with Methadone

8. 9: Opioid pharmacotherapiesBuprenorphine (1) • Buprenorphine is a partial opioid agonist – an opioid analgesic • It has a high affinity (binds) to the opioid receptor sites not allowing other opiates to act but at the same time it gives a partial opioid effect • Buprenorphine is as effective as methadone for people with moderate levels of dependence, & possibly for those with higher levels (Hulse et al. 2002, p. 91) • However, retention on buprenorphine appears to be less than that achieved with methadone • Patient selection is important

9. 9: Opioid pharmacotherapiesBuprenorphine (2) Buprenorphine is available in two forms: • buprenorphine (Subutex) & • buprenorphine-naloxone (Suboxone) • Both forms are usually administered sublingually (usually takes 5 minutes to dissolve) • The tablet (s) can be used whole or in crushed form, as this does not affect sublingual absorption directly • The drug reaches its peak effect after about 3 hours

10. 9: Opioid pharmacotherapiesBuprenorphine (3) • It is easier to taper buprenorphine than methadone, & as a partial agonist is safer in overdose • It results in less respiratory depression than full agonists, such as methadone • A wider safety margin & strong receptor binding leading to a long half-life make alternate day dosing a convenient option for many patients

11. 9: Opioid pharmacotherapiesBuprenorphine – Side effects Some side effects have been reported, however, these are relatively mild and include: • Headache • Sedation • Nausea • Constipation • Anxiety • Dizziness and itching

12. 9: Opioid maintenance treatment in acute hospital setting • Effective nursing care includes appropriate management of a person receiving opioid maintenance treatment during their hospital stay • Because they are taking methadone or buprenorphine, the continued provision of their opioid maintenance treatment is important • This will help maintain their comfort & safety, assist in planning pain management, & prevent the harms associated with poorly managed opioid withdrawal, thus reducing the risk of relapse &/or unplanned early discharge

13. 9: Opioid maintenance treatment in acute hospital setting – General principles • Consult with the drug & alcohol specialist or drug & alcohol nurse practitioner about the care of all patients admitted to hospital who are receiving opioid maintenance treatment • Ensure that their methadone or buprenorphine dose is known & confirmed with prescriber and dosing point, and that the dose is quoted in both mg and mls for methadone • Find out from the prescriber &/or the dispensing pharmacy the timing of the last dose of medication and any takeaway doses

14. 9: Altered tolerance and effective pain management • The patients most likely to have altered tolerance are: • Those who have been on regular prescribed opioid medication for long periods – they may be said to have iatrogenic dependence (medically caused) • Those currently receiving opioid maintenance treatment program or who are currently dependent on opioids • Those who regularly take liver enzyme-inducing drugs (e.g. alcohol, dilantin, interferon and rifampicin etc)

15. 9: Altered Tolerance and effective pain management – Acute Pain Management • Clear communication regarding changes in their medication will help to lessen any anxiety and provide reassurance • It is critical that analgesia is not withheld from the person unless medically indicated • Providing pain relief will not make the person more drug dependent

16. 9: Opioid pharmacotherapiesMethadone – Pain Relief • If a person is being prescribed methadone as a maintenance pharmacotherapy for opioid dependence, even at high doses, they will require additional opioids over & above their daily methadone dose for effective pain relief due to tolerance • Accident & emergency & other nursing & medical staff need to know that a person is taking methadone so that effective pain relief can be offered • Refer to NSW Health Policy Directive PD 2006_ 049. Opioid-dependent Persons Admitted to Hospitals in NSW – Management

17. 9: Opioid pharmacotherapiesBuprenorphine – Pain relief • Standard doses of opioid analgesia are not likely to be effective in any patient who has used buprenorphine within the 3-4 days prior to requiring such analgesics • Advice should be sought from a Medical Officer skilled in drug & alcohol or D&A nurse practitioner in these instances • Accident & emergency & other nursing & medical staff need to know if a person is taking buprenorphine so that effective pain relief can be provided by using non-opioid analgesics, local anaesthetic approaches or higher dose opioid prescriptions in these situations

18. 9: Opioid pharmacotherapiesNaltrexone (1) • As an antagonist, naltrexone blocks both the euphoric & analgesic effects of opioids • It is long acting, with effects lasting between 24 & 72 hours • Use of naltrexone while still opioid-dependent will bring on severe withdrawal symptoms and there are particular management issues for nurses when this drug has been self-administered by opioid users

19. 9: Opioid pharmacotherapiesNaltrexone (2) • If depression occurs as a side effect of Naltrexone, an alternative pharmacotherapy is often considered • Research into its effectiveness shows that there is a high drop-out rate from treatment • Relapse could run the risk of overdose due to reduced opioid tolerance (Gowing et al. 2001; Young et al. 2002)

20. 9: Opioid pharmacotherapiesNaltrexone – Pain relief • Opioid analgesia is not likely to be effective in any patient who has used naltrexone within the previous 7 days • In these instances, advice should be sought from a Medical Officer skilled in drug & alcohol or a D&A nurse practitioner • Accident & emergency & other nursing & medical staff need to know if a person is taking naltrexone so that effective pain relief can be provided by using non-opioid analgesics in these situations

21. 9: Opioid pharmacotherapiesNaltrexone – Withdrawal – Rapid opioid detoxification (ROD) (1) • This form of detoxification is known by a number of names, including “ultra-rapid detoxification”, “accelerated detoxification”, “sedated detoxification” & “detoxification under anaesthetic” • Rapid opioid detoxification is the process of accelerating acute withdrawal by administration of an opioid antagonist, while providing symptomatic relief to enable patients to tolerate the procedure • The detoxification is followed with daily naltrexone treatment either tablets or implants

22. 9: Opioid pharmacotherapiesNaltrexone – Withdrawal – Rapid opioid detoxification (ROD) (2) • For treatment guidelines for the management of opioid withdrawal inadvertently precipitated by naltrexone, see the relevant section in Chapter 9.1, Opioids • Some significant risks have been associated with sedation during ROD, including death as a result of aspiration or respiratory depression • For further information on methadone & buprenorphine treatment, refer to: NSW Opioid Treatment Program: Clinical Guidelines for methadone and buprenorphine treatment. Doc No. GL2006_019. www.health.nsw.gov.au/policies/gl/2006/GL2006_019.html

23. 9: Pharmacotherapies for dependence & maternal & neonatal care • Methadone is the drug of choice for opioid dependent pregnant women • Buprenorphine is not approved but a patient can continue on it if pregnant • Withdrawal for the baby is likely to occur with both of these maintenance drugs as it would with heroin dependence • For information regarding pharmacotherapies for dependence and maternal/neonatal care, refer to the National clinical guidelines for the management of drug use during pregnancy, birth and the early development years of the newborn. (March 2006)http://www.health.nsw.gov.au/pubs/2006/ncg_druguse.html

24. 9: Alcohol pharmacotherapies –Acamprosate (Campral) • Acamprosate is a pharmacotherapy used to prevent alcohol relapse post-withdrawal • It assists in the reduction of cravings for alcohol, where the person is seeking to abstain or reduce their consumption • Compliance can be an issue as dosage is usually two tablets x three times/day (333mg in each tablet) • Acamprosate does not interact with alcohol, and does not have hypnotic, anxiolitic or antidepressant effects

25. 9: Alcohol pharmacotherapies –Naltrexone • Naltrexone suppresses the priming effect of alcohol (blunts the euphoric effects of alcohol and reduces the positive reinforcement of alcohol use) & can assist in achieving goals of reduction in consumption &/or abstinence • Monitoring the liver profile is recommended during the course of naltrexone treatment, which is usually three to six months • A dose of 50mg daily has shown positive outcomes with relapse rates, craving & number of non-drinking days

26. 9: Alcohol pharmacotherapies –Disulfiram (Antabuse) • The goal in prescribing disulfiram is to provide a powerful disincentive to drink – it inhibits the ALDH in the liver, and if the person drinks alcohol, causes an accumulation of acetaldehyde – making them feel sick • Within 15 minutes of drinking the person may experience the following: flushing; feeling heat & sweating; nausea; vomiting; palpitations & rapid pulse; headache; difficulty breathing blood pressure increase then decrease