The Patient with an Addiction Stephan A Schug Anaesthesiology University of Western Australia & Pain Medicine Royal Perth Hospital
Disclosure The Anaesthesiology Unit of the University of Western Australia, but not Professor Schug personally, has received research and travel funding and speaking and consulting honoraria from Eli Lilly, biocsl/seqirus, Grunenthal, Indivior, Janssen, Mundipharma, Pfizer, Phosphagenics and ixbiopharma within the last 5 years.
Terminology
Issues in Acute Pain Management psychological, social and behavioural characteristics associated with an addiction; presence of the drug (or drugs) of abuse; medications used to assist with drug withdrawal, relapse prevention and/or rehabilitation; complications of drug abuse including organ impairment, infectious diseases and increased risk of traumatic injury; the presence of tolerance, physical dependence and withdrawal.
General Principles of Management patient engagement empathic and open communication pragmatic treatment goals provision of effective analgesia use of strategies to attenuate tolerance and prevent withdrawal secure drug administration procedures and discharge planning
Addiction to Drugs Other Than Opioids Alcohol and benzodiazepines no effect on pain relief withdrawal may require substitution sedation Cannabinoids possibly increased opioid requirements higher pain scores lower satisfaction Amphetamines, cocaine no good data on pain and analgesic requirements
Opioids in Patients on Opioids increased requirements reduced efficacy reduced nausea/vomiting paradoxically increased sensitivity with increased sedation and possibly respiratory depression, in particular with dose increase
Always Consider Other Reasons for Increased Opioid Requirements! Acute neuropathic pain Pain due to other causes surgical complication compartment syndrome Major psychological distress Aberrant drug seeking behaviour
Scientific Evidence: Multimodal Analgesia There is Level I evidence for the effectiveness of the following components of multimodal analgesia: Paracetamol NSAIDs/Coxibs Alpha-2-Delta Ligands (pregabalin, gabapentin) Systemic Local Anaesthetics (lignocaine/lidocaine) Ketamine Alpha-2 Agonists (clonidine/dexmedetomidine) Corticosteroids (dexamethasone) Regional anaesthesia (peripheral and epidural)
Whenever Possible Use a Regional Analgesia Technique! Catheter techniques are better than singleshot blocks: epidural analgesia peripheral nerve catheters Regional techniques do NOT prevent withdrawal!
Antihyperalgesic Medications Provide Effective Analgesia and Attenuate Opioid Tolerance and OIH: Ketamine Gabapentin/Pregabalin
Ketamine Provides Better Analgesia Ketamine Placebo
Ketamine Reduces PCA Reqirements
Gabapentinoids Counteract Central Sensitisation / Hyperexcitability
Pregabalin As An Anxiolytic Kavoussi Eur Neuropsychopharmacol 2006;16:S128
Alpha-2-Delta Modulators and OIH/Tolerance In methadone-maintained patients, gabapentin increased cold-pressor pain threshold and pain tolerance. Pregabalin in maintenance program patients reduced methadone requirements and withdrawal symptoms. OIH associated with remifentanil is attenuated by preoperative pregabalin.
Prevention of Withdrawal Maintenance of normal preadmission opioid regimes including on the day of surgery check preadmission opioid doses with GP/pharmacist Substitute with parenteral equivalent if patient NBM Manage withdrawal symptoms should they occur clonidine pregabalin/gabapentin
Alpha-2-Delta Modulators and Withdrawal Pregabalin attenuated naloxone-induced withdrawal symptoms in opioid-tolerant rats (Hasanein 2014 BS). Gabapentin reduced withdrawal symptoms in patients during methadone-assisted detoxification (Salehi 2011 Level III-1). Pregabalin added to methadone in maintenance program patients reduced methadone requirements and withdrawal symptoms compared with placebo (Moghadam 2013 Level II, n=60, JS 5).
Discharge Planning Close liaison with ongoing prescriber/supplier: GP Pharmacist Drug Abuse Service Planning of ongoing analgesia in consideration of risks for the patient, but also the community (diversion increased exposure, overdose risk!) Adjustment of opioid substitution to preadmission doses