Background & Aims
Refractory neuropathic pain, especially, chronic post-surgical pain (CPSP)(1) is a difficult entity to treat and is especially common after certain types of surgery.(2) In 2014, the world’s first, multidisciplinary Transitional Pain Service (TPS) at the Toronto General Hospital (TGH) was developed.(3) We present an interesting case of post-surgical neuropathic pain that almost completely resolved with the use of Paxlovid that was refractory to treatment since the past 7 years. We present an interesting case of post-surgical neuropathic pain that almost completely resolved with the use of Paxlovid that was refractory to treatment since the past 8 years.
It may be worthwhile considering Paxlovid for refractory neuropathic and CPSP.
Methods
A 67 (now 74) year-old female was referred initially to the TPS at our hospital to manage post-surgical incision pain from breast surgery for left-sided pT1c N1a, grade 2, invasive ductal carcinoma, ER/PR positive, HER-2 negative, status post breast conserving surgery performed in February 2016. A few months after her breast surgery, she was diagnosed with two synchronous primary tumors from her right upper lobe and right lower lobe of the lung. She underwent surgical wedge resection and the biopsies were reported to be: T1b N0 adenocarcinoma in the right upper lobe, and a T1a N0 adenocarcinoma in right lower lobe. She was on treatment initially on gabapentin, that provided her with marginal relief. Her primary issue was incisional pain after the breast surgery and she also preferred to take minimal medication as she believed in non-pharmacological approaches for pain control.
Over the years, her incisional pain increased in intensity without relief from conventional therapy.
Results
She was willing to try other medication, and after a short course of opioids, decided against their use due to side effects and sub-optimal pain control. For the past 5 years, she was on gabapentin 100 mg twice day.She was tried on anti-neuropathic topical agents, and a combination of other anti-neuropathic agents but could not tolerate them. The lowest dose she could tolerate was gabapentin at 100 mg BID. Her insomnia continued to get worse. Botulinum injections were tried around the incision, without much relief.
A few months ago, she contracted COVID infection, and was placed on Paxlovid to treat it. After the first dose, she slept for 8 hours that night, and when she woke up, she noticed a significant improvement in her neuropathic pain. By end of the 5-day course, she had minimal pain that she was suffering from all these years. She also noticed a significant improvement in her sleep, and did not need the Zopiclone every night. NRS pain score reduced to 1-2/10, from 6-8/10.
Conclusions
Paxlovid may be an alternative to be considered for refractory neuropathic pain. Anti-retroviral therapy (such as in treating HIV) has been known to causative in sensory neuropathy (4), and the role of oral acyclovir is not thought to be as robust in preventing post-herpetic neuralgia, as per a Cochrane review.(5)
We conducted a literature search but could not find any data that Paxlovid was used to treat neuropathic pain. Most systematic reviews, and other studies including some case reports were focused on the treatment of herpes zoster, and herpes zoster ophthalmicus, with anti-viral therapies. One study concluded that anti-viral therapy was less effective than analgesics in controlling post-herpetic neuralgia. (6)
While the mechanism of Paxlovid reducing the neuropathic pain in our patient is unknown and further studies are needed, it may be worthwhile to consider Paxlovid for refractory neuropathic pain, especially post-surgical pain, to reduce the intensity of pain.
References
1. https://icd.who.int/browse11/l-m/en#/https://id.who.int/icd/entity/302680255 (accessed January 19, 2024)
2. Rosenberger and Zahn. Chronic post-surgical pain e update on incidence, risk factors and preventive treatment options. In BJA Ed, Vol 22 (5), May 2022, Pages 190-6
3. Katz J, Weinrib A, Fashler SR, Katznelzon R, et al. The Toronto General Hospital Transitional Pain Service: development and implementation of a multidisciplinary program to prevent chronic postsurgical pain. J Pain Res. 2015 Oct 12; 8:695-702. doi: 10.2147/JPR.S91924. PMID: 26508886; PMCID: PMC4610888
4. Aziz-Donnelly, A., Harrison, T. B. (2017). Update of hiv-associated sensory neuropathies.. Current Treatment Options in Neurology, , 19(10), 36. https://dx.doi.org/10.1007/s11940-017-0472-3
5.Chen, N., Li, Q., Yang, J., Zhou, M., Zhou, D., He, L. (2014). Antiviral treatment for preventing postherpetic neuralgia.. Cochrane Database of Systematic Reviews, , (2), CD006866. https://dx.doi.org/10.1002/14651858.CD006866.pub3
6. Song, D., He, A., Xu, R., Xiu, X., Wei, Y. (2018). Efficacy of pain relief in different postherpetic neuralgia therapies: a network meta-analysis.. Pain Physician, , 21(1), 19-32. Retrieved from https://ovidsp.ovid.com/ovidweb.cgi?T=JS&PAGE=reference&D=med15&NEWS=N&AN=29357328.
Presenting Author
Anna Lomanowska
Poster Authors
Anna Lomanowska
PhD
Toronto General Hospital, University Health Network
Lead Author
Praveen Ganty
MD
University Health Network
Lead Author
Ala Mahamid (MD)
Toronto General Hospital, University Health Network
Lead Author
Elizabeth Woodford (MD FRCPC)
Toronto General Hospital, University Health Network
Lead Author
Hance Clarke
MD
University Health Network, University of Toronto
Lead Author
Topics
- Models: Chronic Pain - Neuropathic