A Comparison of Postoperative Opioid Requirements and Effectiveness in
Methadone-maintained and Buprenorphine-maintained Patients
Dr. R. A. RussellDepartment of Anaesthesia, Pain Medicine & Hyperbaric Medicine
Royal Adelaide Hospital
Opioid Substitution Therapy
Australian patients on methadone-maintenance therapy (MMT) or buprenorphine-maintenance therapy (BMT) :
1998: 24,6572009: 43,445
AIHW 2009
Buprenorphine
Opioid Pharmacology• Partial mu-agonist & kappa-antagonist• Full mu-agonist at analgesic doses• Anti-hyperalgesic properties• High opioid receptor affinity• Slow offset kinetics
Buprenorphine
Opioid Pharmacology• Partial mu-agonist & kappa-antagonist• Full mu-agonist at analgesic doses• Anti-hyperalgesic properties• High opioid receptor affinity• Slow offset kinetics
Partial opioid blockade ?
To cease or not to cease perioperatively?
BMT Clinical Guidelines
Acute Pain Management: Scientific Evidence
‘…There appears to be little problem if buprenorphine is continued and acute pain managed with the combination of a short acting pure opioid agonist as well as other multimodal analgesic strategies...’
NHMRC Acute Pain Management: Scientific Evidence 3e (2010)
BMT Clinical Guidelines ASRA E-News – January, 2011
For patients undergoing elective surgery with moderate-severe post-operative pain:
• Discontinue BMT 3-7 days prior to surgery.
• Transition to other opioids (e.g. methadone) and non-opioid pain medications.
Study Overview
Method• Audit of APS data (2005-2010)
Inclusion Criteria• MMT & BMT patients• PCA (IV) post-operatively
Exclusion Criteria• Regional analgesia with PCA
Collaborators• Dr Kris Usher & A/Prof Pam Macintyre
Results
Total patients = 51
BMT = 22
BUPcont = 11
BUP ceased = 11
MMT = 29
METH cont = 22
METH ceased = 7
Results
BUP cont.
BUP ceased
METH cont.
METH ceased
Age (yrs) 40.2 0.4
38.9 10.8 39.0 7.2 38.8 7.9
Alcohol 27% 18% 14% 14%
Cannabis 9% 9% 23% 14%
BZD 18% 36% 50% 29%
1st 24hr PCA Requirements
0
50
100
150
200
250
300
Mor
phin
e eq
uiva
lent
s (m
g)
METH (ALL)
METH (CONT)
METH (CEASED)
BUP(ALL)
BUP(CONT)
BUP(CEASED)
180
± 1
39 m
g
211
± 1
30 m
g
281
± 1
29 m
g
196
± 1
28 m
g
155
± 1
35 m
g
245
± 1
09 m
g
1st 24hr PCA Requirements
0
50
100
150
200
250
300
Mor
phin
e eq
uiva
lent
s (m
g)
METH (ALL)
METH (CONT)
METH (CEASED)
BUP(ALL)
BUP(CONT)
BUP(CEASED)
180
± 1
39 m
g
211
± 1
30 m
g
281
± 1
29 m
g
196
± 1
28 m
g
155
± 1
35 m
g
245
± 1
09 m
g
Results
BUP cont.
BUP ceased
METH cont.
METH ceased
Pain – rest 4.1 1.9 4.7 2.2 4.6 2.0 5.4 2.2
Pain – movt. 6.6 1.7 6.9 2.6 7.5 1.7 8.1 2.5
N & V (Req. Rx) 36.4% 27.3% 22.7% 32.9%
Sedn Score = 2* 18.2% 27.3% 18.2% 28.6%
* Overall incidence sedn score of 2 in all RAH APS patients = 1.68%
Results
BUP cont.
BUP ceased
METH cont.
METH ceased
Pain – rest 4.1 1.9 4.7 2.2 4.6 2.0 5.4 2.2
Pain – movt. 6.6 1.7 6.9 2.6 7.5 1.7 8.1 2.5
N & V (Req. Rx) 36.4% 27.3% 22.7% 32.9%
Sedn Score = 2* 18.2% 27.3% 18.2% 28.6%
* Overall incidence sedn score of 2 in all RAH APS patients = 1.68%
Results
BUP cont.
BUP ceased
METH cont.
METH ceased
Paracetamol 100% 100% 100% 100%
Ketamine 27% 100% 54% 71%
Days PCA 2.2 1.4 4.6 3.0 2.7 1.6 6.0 2.8
Days APS 3.0 1.7 5.9 3.9 4.0 2.5 8.7 3.4
Opioid-tolerant PatientsRoyal Adelaide Hospital 1998 (n = 214, PCA)
Opioid-tolerant
1st 24 h PCA Morphine 171 mg
Pain Score - Rest (median) 6
Pain Score - Movt. (median) 8
Sedation score 2 or 3 14%
Opioid-naive vs. Opioid-Tolerant Rapp et. al. 1995 (n = 149, PCA)
Opioid-naive Opioid-tolerant
1st 24 h PCA Morphine 47 32 mg 136 69 mg
Pain Score - Rest 3 5
Pain Score - Movt. 7 8
Sedation score 2 or 3 19% 50.3%
Conclusions
Patients maintained on methadone & buprenorphine substitution therapy:
• High 1st 24 hour PCA opioid requirements• Large inter-patient variability• Higher pain scores• Increased incidence of sedation
Conclusions
Patients maintained on methadone & buprenorphine substitution therapy:
• High 1st 24 hour PCA opioid requirements• Large inter-patient variability• Higher pain scores• Increased incidence of sedation
PCA doses and pain scores are higher if BMT and MMT are ceased perioperatively
Conclusions
Cessation of BMT & MMT
• Higher opioid requirements• Longer duration of PCA therapy• Requirement for more intensive APS management
Conclusions
Cessation of BMT & MMT
• Higher opioid requirements• Longer duration of PCA therapy• Requirement for more intensive APS management
Buprenorphine can be continued perioperatively without adversely effecting pain relief using pure
agonist opioids.
