A practical guide to pain relief in the addicted patient

Dr Mick Rothwell,
Consultant Anaesthetist & Director
Acute Pain Service,
Macclesfield Hospital.

Biography
Originally from Bolton, I went to Medical School at St. Marys’, London in 1984 and completed my Anaesthesia training in and around London in 1998.  I did a 1 year Chronic Pain Fellowship at St.Marys’ Hospital as part of my training.  I have been a Consultant in Anaesthesia at Macclesfield Hospital for 11 years.  I set up and run the Hospitals Acute Pain Service and ran the Chronic Pain Service for 8 months following the resignation of a colleague.  In 1999 I developed a computerised audit system running on handheld devices for the APS and remain interested in computing in medicine.  I chair the local Medicines Management Group and have been an external examiner for Cardiff University MSc in Pain Management for 4 years.  I am now an honorary senior lecturer on the course.  I first lectured on Drug Using Patients as part of a local “Drug User Study Day” in 2000 and have spoken on this an several other topics at local, regional and national meetings.

Abstract
Drug mis-use is very common: 18% of 15yr olds have used drugs in the last month and 12% of these use Class A drugs most days.  There are over 180,000 registered addicts in the UK and 1600 deaths per year in mis-users.  Drug mis-use costs the UK economy nearly £17bn per year.

I will discuss the definition and difference between Tolerance, Dependence and Addiction and explore how they develop from a simplified neurochemical perspective.

• Tolerance= decreasing effect of a drug with prolonged use.
• Dependence can be Physical, where there are physical effects of withdrawal, or Psychological, where cravings predominate and there are no physical symptoms.
• Addiction = A State of physical or psychological dependence on a substance produced by habitual use.  It is characterised by loss of control, compulsive use, preoccupation and continued use despite harm.

 
We will look at Withdrawal syndromes and see why severe physical withdrawal symptoms only occur with depressant substance withdrawal, such as Opioids, Alcohol, and Benzodiazepines.

Drug mis-users have many problems:
Medical problems include: Infections - HIV, Hepatitis, STD’s, Chest infections.  Organ damage - endocarditis, renal or liver damage.  Cardiovascular.  Skin and soft tissue damage.  Blood and blood vessel problems.  Poor Nutritional state
Social Problems include: Anxiety, depression, psychosis, hallucination, Mental illness ?cause or effect.  Suicidal tendency.  Legal/criminal problems.  Withdrawal and drug seeking behaviour.

The Acute Pain Services’ role is to help gain compliance with treatment, avoid anti-social behaviour by the patient and plan for early discharge.  It can be helpful to make a “contract” with the patient early on explaining that “we” will prevent withdrawal and treat pain if “they” do not cause trouble on the ward.  The drug mis-user in pain will need replacement for their normal background drugs plus additional analgesia for their acute pain.  I will discuss how the background doses can be calculated and given.  Additional analgesia will be paracetamol & NSAID (with PPI gastroprotection) & local anaesthetic/ block & additional opioid.
 
The differences between Methadone and Buprenorphine will be explored, particularly the partial agonist property of Buprenorphine, which may antagonise the action of other strong opioids given concurrently.

Treating the drug mis-user in remission and planning for discharge will be covered.  We will conclude with a case report and a consideration of the economic impact that a change in drug policy could have.

References
Drug use, drinking and smoking among young people in England in 2007:National Centre for Social Research, 2008 NHS information centre: Statistics on Drug Misuse 2007.
http://www.tdpf.org.uk/Transform%20CBA%20paper%20final.pdf.
Diagnostic and Statistical Manual of Mental Disorders 4th edition.
http://en.wikipedia.org/wiki/Neurotransmitter
FINNEY, J. W., & MOOS, R. H. (1991). The long-term course of treated alcoholism: 1. Mortality, relapse and remission rates and comparisons with community controls. Journal of Studies on Alcohol, 52, 44-54
HELZER, J. E. ET AL., (1985). The extent of long-term moderate drinking among alcoholics discharged from medical and psychiatric treatment facilities. New England Journal of Medicine, 312, 1678-1682.
Substance Abuse& Mental Health Services Administration: http://www.samhsa.gov/index.aspx
Drug Misuse and Dependence- UK Guidelines on clinical management. http://www.nta.nhs.uk/publications/documents/clinical_guidelines_2007.pdf
RIOTT preliminary report: http://www.slam.nhs.uk/news/docs/Positive%20results%20in%20heroin%20addiction%20trial.pdf
Acute Pain Management in Opioid Dependent Patients- Mehta V. & Langford R.- Reviews in Pain Vol3-no.2, Oct 2009, p10-13
Kantor TG et al.. A Study of hospitalized surgical patients on methadone maintenance therapy. Drug & Alcohol Depend; 1980; 6: 163-73
http://www.tdpf.org.uk/Transform%20CBA%20paper%20final.pdf.