#214 Nerve-ous About Opioids? Treatment of neuropathic pain with opioids
CLINICAL QUESTION
What are the risks and benefits of opioids for neuropathic pain?
BOTTOM LINE
Compared to placebo, high-dose opioids moderately (at least 30%) reduce pain for an additional 1 in every 5-8 people over 4-12 weeks. Opioid-related adverse events lead to discontinuation for 1 in every 11-12 people over placebo. Other medications (like tricyclic antidepressants, gabapentin/pregabalin, and duloxetine) are similarly effective with less adverse events. Opioids should only be considered in patients with refractory pain after multiple therapeutic trials.
Reading Tools for Practice Article can earn you MainPro+ Credits
Join NowAlready a CFPCLearn Member? Log in
EVIDENCE
- Four systematic reviews of 5-31 Randomized Control Trials (RCTs) with 236-1,769 patients followed for 4-12 weeks. Mean age ~60, all versus placebo, in diabetic neuropathy, phantom limb pain, or post-herpetic neuralgia. Morphine equivalent dosing ranged from 7.5 mg/day to 180-240 mg/day.1-5
- Pain control:
- Moderate pain relief (at least 30% improvement) or much/very much improved on a Patient Global Impression of Change scale:1,2
- Morphine: 63% versus 36%, Number Needed to Treat (NNT)=4.
- Oxycodone as monotherapy and/or add-on: 44% versus 27%, NNT=6.
- Monotherapy NNT=5 or add-on NNT=8.
- At least 33% improvement (morphine and oxycodone):3,4
- 57% versus 34%, NNT=5.
- Meta-analysis by Tools for Practice authors (five RCTs, 429 patients): Reduce pain 1.2 points more than placebo on 10-point scale.
- Moderate pain relief (at least 30% improvement) or much/very much improved on a Patient Global Impression of Change scale:1,2
- Function:
- General activity, normal work activities, social relations, sleep, and life enjoyment: Unclear clinical benefit.3
- Example: Outcomes improved between ~0.7 to ~1.7 points out of 10 with morphine or oxycodone versus placebo.
- Mood and walking measures: No benefit.
- General activity, normal work activities, social relations, sleep, and life enjoyment: Unclear clinical benefit.3
- Adverse Events:
- Morphine, oxycodone, and methadone versus placebo:
- Withdrawal due to adverse events: 3,4 Number Needed to Harm (NNH)=11-12.
- Constipation (NNH=4-5),2,3 dizziness (NNH=8),2,3 drowsiness/somnolence (NNH=6-7),2,3 nausea (NNH=6),2,3 vomiting (NNH=12).3
- Morphine, oxycodone, and methadone versus placebo:
- Limitations: Concomitant pain treatment unclear, RCTs had small sample sizes and short duration of studies.
- Pain control:
- Guidelines suggest serotonin-norepinephrine reuptake inhibitors, tricyclic antidepressants, or gabapentin/pregabalin as first-line agents for neuropathic pain.6,7
- Generally, work as well (similar NNT) as high-dose opioids.8
- Opioids inconsistently recommended: From not starting in primary care without specialist advice6 to second-line therapy.7
- Between 2006-2008, 58% of drug-related deaths in Ontario were opioid-related.9
Latest Tools for Practice
#379 Bumpin’ Up the Protection? RSV Vaccine in Pregnancy
How effective and safe is the respiratory syncytial virus (RSV) vaccine (AbrysvoTM) when given during pregnancy?
#378 Tony Romo-sozumab: Winning touchdown in osteoporosis or interception for the loss?
What is the efficacy and safety of romosozumab in postmenopausal women with osteoporosis?
#377 How to slow the flow IV: Combined oral contraceptives
In premenopausal heavy menstrual bleeding due to benign etiology, do combined oral contraceptives (COC) improve patient outcomes?
