DRUG MANAGEMENT IN FIBROMYALGIA

FIBROMYALGIA: YEAR IN REVIEW 

Presentation by Valeria Giorgi; Report written by Janice Sumpton

This report summarizes drug management in fibromyalgia discussed at the 2021 International Congress on Controversies in Fibromyalgia.

CANNABIS

Adding Cannabis to Analgesics:

  • 6-month Italian study observed 102 FM patients with pain scores ≥ 4
  • 2 oil-diluted extracts (22% THC/<1% CBD and 6.3% THC/8% CBD)
  • 64% of patients remained at the end of study
  • Significant improvement in:
               - FM severity (FIQR) in 33% of patients
               - Sleep (PSQI) in 44% of patients
  • Moderate improvement in anxiety and depression in 50% of patients
  • Inverse correlation between BMI and FM improvement (eg. Lower the BMI the greater the improvement)
  • A decrease or holding of usual analgesics seen in 47% of patients
  • 1/3 patients mild side effects that did not change their management
CONCLUSION
  1. Cannabis offers a possible advantage especially in those with sleep difficulties.
  2. Number of patients that remained in the study and the changes in their analgesic use reflects improved quality of life with cannabis.
  3. Further studies needed to confirm these results.
Reference: Clin Exp Rheumatol 2020;38(Suppl. 123): S53-9.

Safety and Efficacy of Cannabis in Fibromyalgia:

  • 6-month study observed 367 FM patients (of which 283 patients taking specifically for FM)
  • 81.1% (194 patients) had at least a moderate or significant improvement at follow-up six months after study ended
  • Age  > 60 yrs and patients with concerns about cannabis use were both associated with treatment failure
  • Spasticity at start of cannabis and previous use of cannabis were both associated with treatment success
  • Side effects reported 6 months after end of study most commonly were dizziness in 7.9% (19 pts), dry mouth in 6.7% (16 pts), nausea/vomiting in 5.4% (13 pts) and hyperactivity in 5% (12 pts)
  • 14 different strains of cannabis used
CONCLUSION:
  1. Cannabis may be an effective and safe treatment for fibromyalgia
  2. Consider cannabis in those not responding to standard care
  3. Further study needed to see effect of cannabis on cognitive impairment, fatigue and other chronic pain syndromes associated with FM
Reference: J Clin Med 2019;8:807.

Cannabis Use and Its Association with Psychological Disorders:

  • Caution using cannabis in patients with underlying psychological conditions since cannabis use is linked to a higher incidence of:
               - Psychosis and schizophrenia
                - Memory impairment
  • Developmental and cognitive disorders
Reference: Psychopharmacol Bull 2020;50(2):56e67.

LOW DOSE NALTREXONE

Low-dose Naltrexone for the treatment of Fibromyalgia: Investigation of Dose-Response Relationships:

  • 27 women (18-60 yrs old) with FM, 2 withdrew, 25 women evaluated
  • Test doses naltrexone were 0.75mg – 6mg and the adjustments to doses were in 0.75mg increments
  • 11 out of 25 patients responded
  • The dose for improvement in 50% of patients was 3.88mg
  • The dose for improvement in 95% of patients was 5.4mg
  • Looking at ten common FM symptoms there was much variation between patients at start of study and variation in symptoms that were improved by naltrexone
CONCLUSION
  1. First look at dose adjustments and their effects
  2. Future study needed with randomized comparison of placebo and naltrexone
  3. 4.5mg dose, previously used seems to be relevant test dose
  4. Need to see effect of naltrexone on non-pain FM symptoms
Reference: Pain Med 2020;21(10):2253-61.

LIDOCAINE

Repeated Intravenous Lidocaine Infusions in Fibromyalgia patients:

  • Higher Doses have a stronger and longer-lasting effect on Pain Reduction.
  • Chart review of 74 FM patients had intravenous lidocaine infusion once every 2 months (Wilderman Medical Clinic, Thornhill, Ontario, Canada)
  • Initial dose was 5mg/kg body weight, if patient had >25% pain relief for < 2 weeks then dose increased to 7.5mg/kg lidocaine alone and third dose change was addition of 2.5g magnesium sulfate to the 7.5mg/kg lidocaine.
  • Evaluated pain (0-10 VAS) just before and after infusion at every visit.
               - 5mg/kg, 7.5mg/kg and 7.5mg/kg lidocaine + 2.5g magnesium produced an average decrease in pain by 2.41 on number scale (statistically significant)
               - No statistical difference at the 7.5mg doses if magnesium was added or not
  • Short-term responders (at least 25% decrease in pain score immediately after infusion):
               - Dose was 5mg/kg in 55.4% of patients
               - Dose was 7.5mg/kg in 83.8% of patients
               - Dose was 7.5mg/kg lidocaine + 2.5g magnesium sulfate in 75.7% of patients
  • Long-term responders (at least 25% decrease in pain relief lasting at least 14 days):
               - Dose was 5mg/kg in 25.8% of patients
               - Dose was 7.5mg/kg in 45.5% of patients
               - Dose was 7.5mg/kg lidocaine + 2.5g magnesium sulfate in 57.6% of patients
  • Maximum Duration of Pain Relief:
               - Up to 49 days after 5mg/kg
                - Up to 90 days after 7.5mg/kg
                - 75 days after 7.5mg/kg lidocaine + magnesium 2.5g
  • Side Effects:
               - Mild to moderate, no major cardiovascular events and resolved shortly after infusion
               - Seen in 10.3% of patients on 5mg/kg dose
               - Seen in 10.8% of patients on 7.5mg/kg dose
CONCLUSION
  • 90 minute lidocaine infusions safely and effectively decrease pain in a significant number of fibromyalgia patients not responding to usual FM treatment
  • Higher doses provided a greater relief in pain
  • The addition of magnesium sulfate showed a trend of greater response but did not show a statistically significant benefit
  • A randomized placebo-controlled trial to look at the different lidocaine doses in fibromyalgia patients is needed
Reference:  Pain Med 2020;21:1230-39.

TRAMADOL

Review of Tramadol for Management of Fibromyalgia Pain and Symptoms:

  • Included 4 studies (459 patients total).
  • Tramadol with acetaminophen improved quality of life compared to placebo BUT tramadol by itself did not show the same benefit.
  • Tramadol + amitriptyline compared to celecoxib + amitriptyline did not show a significant effect on sleep or depressive symptoms.
  • A single dose of intravenous 100mg did not show a significant effect on pain compared to placebo.
CONCLUSION
  1. Did not find enough evidence to use tramadol in fibromyalgia patients
Reference: Int J Clin Pract 2020;74:e13455.