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