methadone mellar davis, wael lasheen, declan walsh
TRANSCRIPT
METHADONE
MELLAR DAVIS, WAEL LASHEEN, DECLAN WALSH
2
SYNTHETIC PSEUDOPIPERDINE DEVELOPED
OVER 50 YEARS AGO
DISTINCTLY DIFFERENT FROM ALKALOID OPIOIDS
(MORPHINE) (CODEINE) AND SYNTHETIC
THEBAINE DERIVATIVES (OXYCODONE)
METHADONE
3
R (L) AND S (D) ENANTIOMER
R ENANTIOMER BINDS WITH SIMILAR AFFINITY TO
MU RECEPTORS AS MORPHINE (KM 3.5NM AND
1.4NM RESPECTIVELY)
BOTH R AND S ENANTIOMERS BIND TO N-
METHYL-D-ASPARTATE RECEPTORS
TWICE THE INTRINSIC EFFICACY OF MORPHINE
METHADONE
4
DELTA OPIOID RECEPTOR AGONIST (R AND S)
SEROTONIN AND NOREPINEPHRINE REUPTAKE
INHIBITOR (R AND S)
HIGH DOSES BLOCK POTASSIUM CHANNELS
METHADONE
5
ABSORPTION RAPID AND COMPLETE (47 - 91%)
DRUG LEVELS CAN BE MEASURED 30 MINUTES AFTER
ORAL DOSING, PEAK CONCENTRATIONS OCCUR AT 2.5
HOURS
INTESTINAL CYP3A4 AND P-GLYCOPROTEIN MAY
REDUCE ABSORPTION
NOT A MAJOR FACTOR IN THE LARGE INTER-
INDIVIDUAL DIFFERENCES IN KINETICS
ABSORPTION
6
PKA IS 9.2 (BETTER ABSORBED IN AN ALKALINE
ENVIRONMENT)
REDUCED ACIDITY (OMEPRAZOLE) INCREASES
ABSORPTION
NON-SATURABLE KINETICS
PRESYSTEMIC CLEARANCE (ABSORPTION AND
BIOAVAILABILITY) IS 21%
UNALTERED BY DIET
ABSORPTION
7
SIMILAR ABSORPTION AND BIOAVAILABILITY AS
ORAL METHADONE
MICROENEMAS > HYDROGENATED OIL BASE
SUPPOSITORIES
RECTAL METHADONE
8
ABSORPTION IS 34% (51% FENTANYL AND 18%
MORPHINE)
BUFFERING THE PH TO 8.5 DOUBLES
ABSORPTION (75%)
SUBLINGUAL METHADONE
9
BIEXPONENTIAL KINETICS
EXTRACTION RATIO 0.08 - 0.16
DEMETHYLATED TO AN INACTIVE METABOLITE
(EDDP) BY CYP3A4
INDUCTION OF CYP3A4 BY METHADONE WITH
CHRONIC DOSING
METABOLISM
10
CYP3A4 > CYP2D6, CYP1A2, CYP2C9, CYP2C19
ULTRARAPID METABOLIZERS HAVE HALF THE
METHADONE DRUG LEVELS AS POOR
METABOLIZERS (HOMOZYGOTE CYP2D6
MUTATIONS)
CYTOCHROME ENZYMES
11
METHADONE CLEARANCE CAN VARY BETWEEN
INDIVIDUALS 100-FOLD (0.023 - 2.1 LITERS PER
MINUTE) WITH A MEAN OF 0.095 LITERS PER
MINUTE
METHADONE CLEARANCE
12
MU OPIOID RECEPTOR GENETICS
P-GLYCOPROTEIN ACTIVITY
CYP3A4 BASAL AND INDUCTION ACTIVITY
CYP2D6, CYP1A2, CYP2C9, CYP2C19
GENOTYPE OF ALPHA1 ACID GLYCOPROTEIN
CO-MEDICATIONS
CAUSES OF INTERINDIVIDUAL DIFFERENCES IN METHADONE
13
ORAL
SUBLINGUAL (1:1)
RECTAL (1:1)
SUBCUTANEOUS (2:1)
INTRAVENOUS (2:1)
ROUTES
14
RIFAMBUTIN (FOR RIFAMPICIN)
FAMOTIDINE (FOR CIMETIDINE)
MIRTAZAPINE (FOR SSRI)
HALOPERIDOL OR OLANZAPINE (FOR
RESPERIDONE)
VALPROIC ACID, GABAPENTIN (FOR
PHENOBARBITOL, PHENYTOIN, CARBAMAZEPINE)
SAFE COMBINATIONS
15
SIMILAR TO OTHER OPIOIDS
REDUCED CONSTIPATION COMPARED TO
MORPHINE
TORSADES DE POINTES AND PROLONGED QTC
WITH INCREASED RISK PARTICULAR WITH
PARENTERAL
METHADONE TOXICITY
16
MORE COMMON WITH INITIAL THERAPY
DEATHS AT STEADY STATE ARE RELATED TO:
INTERFERING CO-MEDICATION
ILLICIT DRUG TAKING (DIAZEPAM, ALCOHOL, COCAINE,
CANNABIS, OTHER OPIOIDS)
DEATH FROM METHADONE
17
THE ORIGINAL MANUFACTURER’S
RECOMMENDATION OF 2.5 - 10MG EVERY 3 - 4
HOURS IS EXCESSIVE.
EQUIANALGESIA TABLES THAT PUT
EQUIVALENTS NEAR UNITY WITH MORPHINE ARE
DANGEROUS.
METHADONE AND CANCER PAIN
18
METHODS OF OPIOID ROTATION INVOLVE A
“STOP-START” STRATEGY
A Q 3-HOUR AS NEEDED SCHEDULE
LINEAR RATIO BASED UPON MORPHINE EQUIVALENTS
EVERY 8 HOURS ATC
METHADONE AND CANCER PAIN
19
MORPHINE:METHADONE
4:1 < 90MG MORPHINE DAILY
8:1 90 - 300MG MORPHINE DAILY
12:1 300 - 1000MG MORPHINE DAILY
20:1 > 1000MG MORPHINE DAILY
DIVIDE DOSE INTO 3 AND GIVE EVERY 8 HOURS
OPIOID NAÏVE; 3 - 5MG EVERY 8 HOURS OR 7.5MG
EVERY 12 HOURS
EQUIVALENTS AND DOSING
20
STOP-START
USE 10% OF TOTAL MORPHINE (OR MORPHINE EQUIVALENTS)
UP TO A SINGLE MAXIMUM DOSE OF 30MG METHADONE
DOSE EVERY 3 HOURS AS NEEDED
STEADY STATE OCCURS AT DAY 4 AND 5
TOTAL DOSES ON DAY 4 AND 5, DIVIDE BY 4 AND GIVE EVERY
12 HOURS
EQUIVALENTS AND DOSING
21
SHOULD BE DONE BY SOMEONE WITH
EXPERIENCE
DO NOT ADD BENZODIAZEPINES DURING
TITRATION, AVOID ALCOHOL
USE ACETOMINOPHEN IF PAIN RECURS BEFORE
THREE HOURS
METHADONE DOSING
22
HYDROMORPHONE
PARENTERAL HYDROMORPHONE TO ORAL METHADONE
1.07 + 0.9
FENTANYL
FENTANYL 25µG TO 0.1MG PARENTERAL METHADONE
EQUIVALENTS WITH OTHER OPIOIDS
23
DOSE RATIOS BETWEEN MORPHINE AND
METHADONE ARE NOT DEPENDENT UPON THE TYPE
OF PAIN
GROND S. PAIN 1999
GAGNON B. JPSM 1999
NEUROPATHIC PAIN
24
REFRACTORY PAIN
PATIENTS ON HIGH DOSE OPIOIDS WITH
BURDENSOME COSTS
PATIENTS WITH LIMITED FINANCES
HOSPICES
NEUROPATHIC PAIN
CHEAP SUSTAINED RELEASE OPIOID
CANDIDATES FOR METHADONE
Ripamonte C. Pain 1997
25
METHADONE
PROS
1) LACK OF ACTIVE METABOLITES
2) SAFETY IN ORGAN FAILURE
3) HIGH LIPID SOLUBILITY
4) HIGH BIOAVAILABILITY
5) VERSATILITY
6) LOW COST
CONS
1) UNPREDICTABLE AND LONG HALF-LIFE
2) INTERINDIVIDUAL VARIABILITY
3) CHANGING EQUIANALGESIC POTENCY WITH DOSE
26
METHADONE IS UNIQUE PHARMACOLOGICALLY
MULITPLE RECEPTOR AGONIST, NMDA
ANTAGONISTS AND MONOAMINE REUPTAKE
INHIBITORS
RELATIVELY SAFE IN ORGAN FAILURE
DOSING SCHEMES ARE DIFFERENT THAN WITH
OTHER OPIOIDS
SUMMARY
27
28
METHADONE AND CARDIAC
TOXICITY
29
METHADONE HAS BEEN ASSOCIATED WITH
PROLONGED QTC AND TORSADES DE POINTES
(TDP)
UNIQUE BLOCK OF IONIC CURRENT THROUGH
SPECIFIC TYPE CARDIAC K+ CHANNELS
CARDIAC K+ CHANNELS ARE DERIVED FROM
HUMAN ETHER-A-GO-GO-RELATED GENE (HERG)
INTRODUCTION
30
DELAYED REPOLARIZATION LEADS TO
PROLONGED QTC INTERVALS (>500 MSEC) AND
VENTRICULAR TACHYCARDIA (TDP)
ALSO INTERLEAD VARIATION BETWEEN QTC
INTERVALS ON SURFACE LEADS
INTRODUCTION
31
32
METHADONE INCREASES QTC IN 30%
QTC > 500 MSEC RANGE 0 – 16% (5%)
POOR CORRELATION WITH DOSE
MAY BE ASSOCIATION WITH HYPOKALEMIA,
STRUCTURAL HEART DISEASE, LIVER DISEASE AND
DRUGS THAT INHIBIT CYTOCHROMES OR PROLONG
QTC
SUMMARY OF ORAL METHADONE AND QTc
33
NO MONITORING FOR LOW RISK INDIVIDUALS
AT RISK INDIVIDUALS, BASELINE ECG REPEAT IF:
BASELINE QTC > 430 M SEC
HIGH DOSE SYMPTOMS (SYNCOPE, PALPITATION, DYSPNEA)
CO-MEDICATIONS THAT PROLONG QTC
RECOMMENDATIONS
34
DOSE REDUCE, ADD ADJUVANT
DELETE MEDICATIONS WHICH PROLONG QTC OR
BLOCK CYTOCHROMES
ROTATE TO MORPHINE OR BUPRENORPHINE OR
FENTANYL
MANAGEMENT OF PROLONGED QTc METHADONE
35
TOXICITY CAN OCCUR AT LOW DOSES (0.4 MG/H)
BASELINE ECG AND REPEAT 24 – 72 HOURS
MONITOR K+
AVOID DRUGS THAT PROLONG QTC
OPTIONS IF QTC >500 MSEC
SWITCH TO ORAL METHADONE
DELETE CO-MEDICATIONS THAT PROLONG QTC
DOSE REDUCE/ADD AN ADJUVANT
ROTATE TO MORPHINE, BUPRENORPHINE
IV METHADONE AND QTc
36
DEATHS: UNINTENTIONAL OVERDOSE, DRUG
INTERACTIONS, AND CARDIAC TOXICITY (QT
PROLONGATION AND TDP)
PHYSICIAN’S NEED TO UNDERSTAND TOXICITY AND
UNIQUE METHADONE PROPERTIES
DOSES SHOULD BE CAREFULLY CHOSEN AND SLOWLY
TITRATED
CAREFULLY MONITOR WHEN SWITCHING TO
METHADONE AND CHANGING DOSE
FDA BLACK BOX WARNING
37
LOW RISK WITH ORAL METHADONE
AT RISK INDIVIDUALS REQUIRE MONITORING
RISK GREATER WITH PARENTERAL METHADONE DUE
TO CHLOROBUTANOL
PARENTERAL METHADONE REQUIRES ROUTINE ECG
MONITORING
RISK AND BENEFITS OF METHADONE MUST BE
WEIGHED IF NO OTHER TREATMENT OPTIONS ARE
AVAILABLE IN TERMINAL PATIENTS
SUMMARY
38
PATIENT CONTROLLED
ANALGESIA (PCA)
MELLAR DAVIS, WAEL LASHEEN, DECLAN WALSH
39
CONCEPT
INTER-INDIVIDUAL VARIABILITY
OPTIMIZE OPIOID ADMINISTRATION
IMMEDIATE ACCESS
ON DEMAND > CONVENTIONAL DOSING
BACKGROUND
40
FIRST PCA PUMP 1976
MODALITIES
DEMAND ONLY
CONTINUOUS INFUSION + DEMAND
INFUSION RATE BASED ON DEMAND
VARIABLE RATE
VARIABLE RATE FEEDBACK
PCA MODALITIES
41
PCA SETUP: DRUG CHOICE
OPIOIDS
ALL OPIOIDS
SHORT ACTING ARE SAFER THAN LONG ACTING
NON-OPIOIDS
MOST COMPATIBLE WITH OPIOIDS
• ATROPINE, DEXAMETH, DIAZEPAM,
LORAZEPAM, KETEROLAC, HALDOL,
LEVOPROME, METOCHLOPRAMIDE
PHYENYTOIN IS NOT COMPATIBLE WITH OPIOIDS
42
PCA ROUTES OF DELIVERY
INTRAVENOUS
SUBCUTANEOUS
INTRAMUSCULAR
ORAL,NASAL,SUBLINGUAL
SPINAL, VENTRICULAR
OTHERS...
43
PCA STRATEGY
• LOADING DOSE
• DEMAND DOSE
• LOCKOUT INTERVAL
• CONTINUOUS INFUSION
• DOSE LIMITS
44
PATIENT REMOVES DELAY DEMAND / DELIVERY
PATIENT CONTROL / SECURITY
DETERMINE PAIN THRESHOLDS
DOSING ASSESS ANALGESIC REQUIREMENTS
INFLUENCES TRADITIONAL DOSING PROTOCOLS
ADAPTABLE INTERINDIVIDUAL REQUIREMENTS
TEMPORAL PAIN PATTERN
PCA ADVANTAGES
45
PATIENT RISK FACTORS
AGE
HEAD INJURY
SLEEP APNEA
OBESITY
RESPIRATORY FAILURE
BENZODIAZEPINES
HYPONATREMIA
RENAL FAILURE
46
COMPLICATIONS
OPERATOR ERRORS
PROGRAMMING ERRORS
ACCIDENTAL BOLUS
INAPPROPRIATE
DOSE
LOCKOUT
DRUG SELECTION
SURROGATE ACTIVATION
PUMP MALFUNCTION
47
AGE = > 5 YRS
COGNITIVE ABILITY
UNDERSTAND THE RELATIONSHIPS BETWEEN PAIN,
ACTIVATING THE PUMP, AND GOALS OF PAIN RELIEF
INTACT MEMORY
PHYSICAL ABILITY TO ACTIVATE THE BUTTON
PSYCHOLOGICAL: NEED TO MAINTAIN CONTROL
EXTREME FEAR OF SIDE EFFECTS
PRESENCE OF A RELIABLE SURROGATE
PATIENT SELECTION
48
INCIDENT PAIN
KIDNEY FAILURE (DEMAND ONLY)
EXCESSIVE SIDE EFFECTS (N&V, SEDATION)
INTESTINAL OBSTRUCTION
IMPAIRED ORAL INTAKE
CIRCARDIAN VARIATION IN PAIN INTENSITY
INITIAL TITRATION
PCA IN CANCER MAYBE USED IN:
49
LOADING DOSE
DEMAND DOSING & CONTINUOUS INFUSION(CI)
A DOSE SHOULD RESULT IN PERCEPTIBLE ANALGESIA
TITRATION
LOCKOUT INTERVAL
PHARMACOKINETICS / DYNAMICS, CNS DWELL TIME
LONG ENOUGH FOR THE PATIENT TO EXPERIENCE BENEFIT
LONGER IF CONCOMITTENT CONTINUOUS INFUSION
PCA DOSING (INTRODUCTION)
50
OPIOID NAIVE: 0.5MG/H CI , DEMAND 1MG Q2H
OPOID TOLERANT: THE HOURLY MORPHINE DOSE
Q2HRS, RARELY Q1HR
RATIONALE LONG CNS DWELL TIME
DEMAND DOSE IS TITRATED TO BREAKTHROUGH
PAIN SEVERITY AND DURATION
PCA DOSING IN CANCER
51
MORPHINE LOADING TO EFFECTIVE ANALGESIA: 2-5MG Q 10 MINUTES
DEMAND DOSE USE 50 -75% OF LOADING DOSE
CONTINUOUS INFUSION: PRE-OPERATIVE DOSE
>50% PRE-OP DOSE TO AVOID WITHDRAWAL
HOURLY OPIOID REQUIREMENT: 75% BY CI
25% BY DEMAND
POST-OP DOSING (ON OPIOID)
52
PCA OPIOID DEMAND LOCKOUT CI
MORPHINE 1-2MG 6-10 0-2MG/H
HYDROMOR 0.2-0.4MG 6-10 0-0.4MG/H
FENTANYL 20-40MCG 5-10 0-60MCG/H
SUFENTANIL 4-6MCG 5-10 0-8MCG/H
TRAMADOL 10-20MG 6-10 0-20MG/H
POST-OP DOSING (OPIOID NAIVE)
53
RARELY STUDIED
PCA SEEMS USEFUL AND SAFE
COMPLICATION RATES UNKNOWN
OPTIMAL DOSING AND LOCKOUT UNKNOWN
CONCLUSION: PCA IN CANCER
54
PERIOPERATIVE
MANAGEMENT OF
CHRONIC PAIN PATIENTS
55
CHRONIC PAIN
“PAIN WITHOUT APPARENT BIOLOGIC VALUE WHICH
PERSISTS BEYOND NORMAL TISSUE HEALING TIME”
(3 MONTHS)
PATHOLOGY DOES NOT EXPLAIN PAIN PRESENCE OR
EXTENT
10-55% IN NORMAL POPULATION
> 50% IN ADVANCED CANCER
INTRODUCTION
Turk, DC 2001
56
MODERATE TO SEVERE PAIN IN 20-30%
CARDIOPULMONARY COMPLICATIONS
UNEXPECTED ADMISSIONS FROM AMB. SURGERY
PROLONGED CONVALESCENCE
SIGNIFICANCE OF POST-OP PAIN.
57
POORER PAIN CONTROL
INCREASED OPIOID REQUIREMENTS
3X EPIDURAL MORPHINE THAN OPIOID-NAÏVE
4X MORPHINE BY INTERMITTENT BOLUS
POSTOPERATIVE PCA DOSES > REPLACEMENT
POST-OP PAIN IN OPIOID TOLERANT.
58
PROGRESSIVE CANCER
TOLERANCE
OPIOID-INDUCED HYPERALGESIA
INCREASED PAIN SENSITIVITY
CAUSES OF INCREASED POSTOPERATIVE PAIN AND OPIOID REQUIREMENTS IN OPIOID-TOLERANT.
59
↓ NAUSEA & PRURITUS IN OPIOID-TOLERANT
DIFFERENCES IN SIDE EFFECTS BETWEEN OPIOID-NAÏVE AND TOLERANT INDIVIDUALS
DELEON CASASOLA 1993
RAPP 1995
60
MINIMAL EFFECTIVE OPIOID DOSE IS UNKNOWN
POSTOPERATIVE OPIOID > ANTICIPATED
ADEQUATE OPIOIDS TO AVOID WITHDRAWAL
TRANSITION TO PREOPERATIVE OPIOID DOSES
CHALLENGING AND OFTEN DELAYED
OPTIMIZING PERIOPERATIVE OPIOIDS USE IN OPIOID-TOLERANT
61
EPIDURALS
REGIONAL BLOCKS
DISCONTINUE NSAIDS 48 HRS BEFORE EPIDURAL
OPIOID DOSE MAINTAINED ON DAY OF SURGERY
PLAN PERIOPERATIVE MANAGEMENT
62
EXPECT OPIOID REQUIREMENTS 2-4 X NAÏVE
INDIVIDUALS
START PCA
ORAL ROUTE: 1.5X PREOPERATIVE ORAL OPIOID
DOSE PLUS DEMAND ONLY FOR RESCUE DOSES
ACUTE POSTOPERATIVE MANAGEMENT .
63
ACUTE POSTOPERATIVE MANAGEMENT .
IV ROUTE: CONTINUOUS DOSE TO MATCH
PRE-OP OPIOID REQUIREMENT + DEMAND
REGIONAL BLOCK: PROVIDE ½ THE PRE-OP
OPIOID DOSE
ADD ADJUNCT (ACETAMINOPHEN,
KETOROLAC, KETAMINE, GABAPENTIN)
64
USE OPIOID DOSE DURING FIRST 24-48 HOURS
DELIVER ½ AS LONG-ACTING OPIOID
DELIVER ½ AS RESCUE EVERY 3-4 HOURS
ADD NSAID, ACETAMINOPHEN AND TAPER OPIOID
MANAGEMENT POSTOPERATIVE TRANSITION PHASE
65
66
MAINTENANCE OPIOIDS (BUPRENORPHINE ,
METHADONE) PROVIDES ADEQUATE ANALGESIA
POSTOPERATIVE
USE OF SHORT ACTING OPIOIDS IN THE
POSTOPERATIVE PERIOD INCREASES RISK OF
ADDICTION RELAPSE
PERIOPERATIVE MANAGEMENT OF ADDICTION: MISCONCEPTIONS
67
PERIOPERATIVE MANAGEMENT OF ADDICTION: MISCONCEPTIONS ADDITIVE EFFECTS OF SHORT ACTING OPIOIDS
WITH MAINTENANCE OPIOIDS INCREASES
RESPIRATORY DEPRESSION
REPORTING PAIN MAY BE A MANIPULATION TO
OBTAIN OPIOID ANALGESICS OR DRUG SEEKING
68
PSEUDO-ADDICTION:”DRUG SEEKING” DUE TO
INADEQUATELY CONTROLLED PAIN
THERAPEUTIC DEPENDENCE:”DRUG SEEKING”
OUT OF FEAR OF EMERGENCE OF WITHDRAWAL
PSEUDO-OPIOID DEPENDENCE:CONTINUED
REPORTS OF PAIN TO PREVENT CURRENTLY
EFFECTIVE DOSES OF OPIOIDS FROM BEING
REDUCED
ISSUES PARTICULAR TO ADDICTION
69
REASSURANCE THAT ADDICTION DOES NOT
PREVENT PAIN CONTROL
CONTINUE OPIOID MAINTENANCE IN THE
PERIOPERATIVE PERIOD
CONFIRM OPIOID TIMING AND DOSE WITH
ADDICTION SPECIALIST
DISCUSS PAIN MANAGEMENT PLANS W/ PATIENT
MANAGEMENT
70
SHORT ACTING OPIOIDS TO TREAT PAIN
REQUIREMENTS MAY BE 3-4 Fold > OPIOID NAÏVE
MAY REQUIRE SCHEDULED RATHER THAN AS
NEEDED SHORT ACTING OPIOIDS
DO NOT STOP MAINTENANCE THERAPY
PCA MAY BE USED BUT SHOULD BE MONITORED
MANAGEMENT
71
CONTINUE BUPRENORPHINE AND ADD SHORT
ACTING OPIOIDS
DIVIDE & GIVE BUPRENORPHINE EVERY 6-8 HRS
DISCONTINUE BUPRENORPHINE AND USE SHORT
ACTING OPIOIDS VIA CONTINUOUS AND DEMAND
PCA
MANAGEMENT BUPRENORPHINE MAINTENANCE
72
MANAGEMENT BUPRENORPHINE MAINTENANCE
CONVERT TO 20-40MG METHADONE DAILY
AND USE SHORT ACTING OPIOIDS FOR PAIN
CONVERT BACK TO BUPRENORPHINE AT
DISCHARGE
73
Buvanendran, A. and J. S. Kroin (2007). "Useful adjuvants for postoperative pain management." Best Pract Res
Clin Anaesthesiol 21(1): 31-49.
Carroll, I. R., M. S. Angst, et al. (2004). "Management of perioperative pain in patients chronically consuming
opioids." Reg Anesth Pain Med 29(6): 576-91.
De Leon-Casasola, O. A., D. P. Myers, et al. (1993). "A comparison of postoperative epidural analgesia between
patients with chronic cancer taking high doses of oral opioids versus opioid-naive patients." Anesth Analg 76(2):
302-7.
Kopf, A., A. Banzhaf, et al. (2005). "Perioperative management of the chronic pain patient." Best Pract Res Clin
Anaesthesiol 19(1): 59-76.
Rapp, S. E., L. B. Ready, et al. (1995). "Acute pain management in patients with prior opioid consumption: a case-
controlled retrospective review." Pain 61(2): 195-201.
Rapp, S. E., L. B. Ready, et al. (1995). "Acute pain management in patients with prior opioid consumption: a case-
controlled retrospective review." Pain 61(2): 195-201.
Tiippana, E. M., K. Hamunen, et al. (2007). "Do surgical patients benefit from perioperative gabapentin/pregabalin?
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REFERENCES
74
CASE 1
• 48 YEAR OLD FEMALE WITH OVARIAN CANCER AND TOXICITY AS WELL AS FOR RESPONSE TO MORPHINE SR 60MG TWICE DAILY FOR ABDOMINAL PAIN
• PHYSICAL EXAMINATION DEMONSTRATES WASTING, ASCITES ,PERIUMBILICAL NODES
• MEDICATIONS:SERTRALINE 50MG, METOPROLOL 25MG TWICE DAILY AND ORAL STOOL SOFTENERS
75
CASE 1
• ECG QTC 450MSEC
• LABORATORY:CREATININE 1.8, NORMAL BILIRUBIN
76
CASE 1:TREATMENT
• METHADONE SHOULD NOT BE STARTED DUE TO THE QTC INTERVAL
• METHADONE SHOULD NOT BE USED DUE TO INTERACTIONS WITH SERTRALINE
• METHADONE SHOULD NOT BE STARTED DUE TO THE CREATININE
• “STOP-START” STRATEGY MAY BE USED WITH STOPPING MORPHINE AND STARTING METHADONE 10MG EVERY 3 HOURS AS NEEDED
77
CASE 1
• YOU START METHADONE EVERY 3 HOURS AS NEEDED
• 6 DAYS LATER SHE IS TAKING 20MG PER DAY ON AVERAGE WITH PAIN CONTROL.
• SHE IS DISCHARGED HOME ON METHADONE 10MG TWICE DAILY AND EVERY 3 HOURS AS NEEDED
• TWO WEEKS LATER SHE IS ADMITTED WITH NAUSEA AND VOMITING AND IS UNABLE TO TAKE HER ORAL MEDICATIONS.
78
CASE 1
• REPEAT ECG QTC 460 MSEC
• IV HYDRATION IS STARTED
79
CASE 1:TREATMENT
• STOP METHADONE AND START FENTANYL OR BUPRENORPHINE
• START METHADONE IV AT 0.5MG PER HOUR WITH 0.5-1MG EVERY 3 HOURS, REPEAT ECG IN 2-3 DAYS
• SWITCH TO RECTAL METHADONE 10MG EVERY 12 HOURS AND AS NEEDED
• START HALOPERIDOL FOR NAUSEA AND OBTAIN A PLAIN X-RAY OF THE ABDOMEN
• START ONDANSETRON FOR NAUSEA AND OBTAIN A PLAIN X-RAY OF THE ABDOMEN
80
CASE 2
• 65 YEAR OLD FEMALE WITH BREAST CANCER ON 40MG METHADONE TWICE DAILY FOR BONE PAIN
• SHE SUSTAINS A PATHOLOGIC HIP FRACTURE REQUIRING SURGERY
• MEDICATIONS: METHADONE , TEMAZEPAM 15MG AT NIGHT, PRINIVIL 20MG DAILY AND LAXATIVES
• LABORATORY: NORMAL CREATININE AND BILIRUBIN
81
CASE 2 :TREATMENT
• DISCONTINUE METHADONE ON THE DAY OF SURGERY AND USE AS NEEDED HYDROMORPHONE 2MG HOURLY AS NEEDED
• USE METHADONE 7.5MG EVERY 3 HOURS AS NEEDED FOR PAIN FOR POST- OP PAIN
• CONTINUE METHADONE 40MG TWICE DAILY IN THE POST- OP PERIOD AND USE HYDROMORPHONE 0.8-1MG EVERY 1-2 HOURS AS NEEDED BY PCA
• START KETOROLAC 15MG IV Q 6 HOURS POST- OP AND CONTINUE METHADONE 40MG TWICE DAILY
• AVOID COMBINING SHORT ACTING POTENT OPIOIDS AND METHADONE. USE TRAMADOL100MG EVERY 6 HOURS WITH METHADONE