Post on 22-Jun-2020
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 single-
shot 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