REGRESSION EQUATION
Repetitive research (see references
below) shows that equianalgesic ratios between methadone and
morphine are dose dependent and vary depending on dose. Studies
show relationships that vary considerably with the most conservative
ratio listed above in Table 2 (Ms : Me). Intuitively the
variation in ratio occurs gradually, not at sudden intervals.
A regression equation can be
derived that estimates the relationship based on gradual change in
ratio. Below is one regression equation derived from slightly more
aggressive ratios than in table 2.
Please use
with caution.
Special thanks to Louis
Gallerani for deriving the equation and plotting the graph.
REFERENCES
Main reference:
Quigley C. Opioid Switching to improve pain relief and drug
tolerability. Cochrane Review, 2004, Issue 3, pg1-34 (everyone
should have this comprehensive review and use it to access primary
literature)
Additional references:
Pereira J et al. Equianalgesic
Dose ratios for Opioids: a critical review and proposals for long
term dosing. J of Pain and Symp Mgt, 22(2), August 2001, pg
672-687
Benitez-Rosario MA et al. Opioid
switching from transdermal fentanyl to oral methadone in patients
with cancer pain. Cancer, 2004, Dec 15;101(12):2866-72
Kornick CA et al. A safe and
effective method for converting cancer patients from IV to TD
fentanyl. Cancer, 2001, Dec 15; 92(12):3056-61
ADJUVANT THERAPIES FOR PAIN
Bone Pain
NSAIDS, steroids, calcitonin, bisphosphonates
- ibuprofen 600 mg every 6 hours
(no NSAID has been proven any more effective than any other in large
studies though individual responses vary)
- if one NSAID does not work, try another in a different class
Neuropathic Pain
gabapentin, TCA’s, topical anesthetics
- gabapentin 100 mg po tid rapidly escalating to up to 4800 mg/d
- desipramine 10-25 mg po qhs up to 100 mg po qhs
- transdermal lidocaine 5% applied as needed
- compounded mixes (ie ketamine 5-10%; amitriptylline 2-5%;
ketoprofen 10-20%; baclofen 2-10%)
Muscle Spasm
- baclofen 5-20 mg 2-4 times per day up to 60 mg/day
- tizanidine 2-8 mg tid up to 36 mg/day
Tramadol
50-100 mg tid
Also
Cognitive Behavioral Therapy
Physical treatments (heat, cold, splinting)
Sensual Therapy (art, music, touch, aromatherapy)
Spiritual assessment and treatment
Pocket Cards
Available
This information is available on plastic laminated Pocket Cards
directly from the
New Hampshire
Hospice and Palliative Care Organization.
ORDERING
Information and ORDER FORM available HERE.
Please Note: The foregoing information was produced as a guide ONLY.
All doses and recommendations should be checked and verified by an
experienced provider prior to use. The authors assume no
responsibility for its use.
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Hospice
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Organization