Dear Pain Matters blog readers,
Almost 2 years ago, I wrote a Blog Post called:
Ziconotide (Prialt) for Nerve Pain Including CRPS?
Quoting from my older Blog Post:
“….Ziconotide for 7 CRPS Patients ….. 2 patients had complete pain relief and as such, discontinued Ziconotide treatment altogether…… (Kapural et al, 2009).”
I find it fascinating that intrathecal (IT) ziconotide treatment resulted in complete pain relief for these 2 patients.
It is worthwhile elaborating further on these 2 former CRPS1 patients here:
(1) Patient 1 –
A male patient (Patient # 1, 16 years old, male) had CRPS1 in both of his legs following an Achilles tendon tear 2 years earlier. He suffered burning pain, hypersensitivity to touch/temperature changes and loss of proprioception in both feet. Pain management treatments including lumbar sympathetic blockade and various oral medications were unsuccessful. The patient used a wheelchair for mobility.
During a ziconotide trial, dosages were titrated from 2.4 mcg/d to 24 mcg/d over 3 months. His VAS score reduced from 100 mm to 40 mm by the 4th month of the ziconotide trial, and he was able to upgrade from a wheelchair to a cane for mobility.
The patient underwent IT pump implantation, and dosages were titrated from 5 mcg/d to 7.5 mcg/d over a 7 month period (with some side effects that were treated).
During the 2nd year, ziconotide dosage was reduced to 4.5 mcg/d. The patient was finally pain-free, and he was able to resume normal activities.
By the 3rd year, ziconotide dosage was further reduced to 1.2 mcg/d, and he stopped taking oral medications altogether. The patient continued ziconotide treatment (ranging from 1.2 to 1.4 mcg/d) for another 4 years, and this enabled him to be pain-free and active.
Post-7 years ziconotide treatment, during which he remained pain-free, (quoting from page 299) ‘his IT pump was filled with normal saline in preparation for an explanation’ (Kapural et al, 2009).
(2) Patient 2 –
A female patient (Patient # 2, 32 years old, female) had CRPS1 in both of her legs due to a fall 5 years earlier. The patient suffered burning pain and hypersensitivity to touch/temperature changes, and she preferred to use a wheelchair for mobility. Pain management treatments had failed her completely including multiple oral medications, lumbar sympathetic blockade and spinal cord stimulator, SCS (VAS score, 100 mm).
Following a successful ziconotide trial, she agreed to IT pump implantation. Dosages were gradually titrated upwards from 10 mcg/d to 145.5 mcg/d over 2 years, with no adverse events. The patient continued at this dosage of 145.5 mcg/d for another 6 years.
After 8 years of ziconotide treatment, the IT pump no longer worked. While waiting for a new IT pump, the patient noticed that she no longer had any pain. As such, she stopped taking systemic opioid medication. She was also able to walk without an assistive device. Her defective IT pump and SCS were surgically removed one month later.
A year following removal of her IT pump and SCS, the patient remained pain free (VAS score, 0 mm) and had returned to college (Kapural et al, 2009).
Ziconotide treatment (via a spinally-implanted pump) can offer significant pain relief, and may even, at appropriate dosages, lead to full recovery from CRPS1 for selected CRPS patients.
It is paramount that ziconotide be titrated to avoid serious side effects. The importance of correct dosage was discussed at great length in an earlier Blog Post:
“Sedare dolorem divinum opus est”
“It is divine to alleviate pain”
Galen, 130-200 C.E.
PS For those of you who want to learn more about cone snails (that inspired medical research into ziconotide), here is a 2 – 3 minute YouTube called ‘Killer Cone Snails’.
NB If you find aggressive animal behaviour disturbing, please refrain from watching this YouTube:
(1) Kapural L, Lokey K, Leong MS, Fiekowsky S, Stanton-Hicks M, Sapienza-Crawford AJ, Webster LR (2009)
Intrathecal Ziconotide for Complex Regional Pain Syndrome: Seven Case Reports.
Pain Practice (2009), 9: 296–303.
More on Intrathecal Delivery of Ziconotide –
(2) Palca, Joe
Snail Venom Yields Potent Painkiller, But Delivering The Drug Is Tricky
3 August 2015