Treatment for Cancer-Related Peripheral Neuropathy
Treatment is similar to that of non-cancer related PN. Gabapentin is considered to be the treatment of choice. TCAs and SSRIs are not as effective or well tolerated. Carbamazepine may be beneficial but its hepatic and hematological side effects make it less desirable for cancer patients. Data regarding oxcarbazepine is very limited. Lamotrigine has shown promise with indications that a good number of patients respond favorable. It also has the advantage of no hepatic side effects and the rash (if it occurs) is considered tolerable. Capsaicin can be used at any time.
Massage and stretching help alleviate cramps and some benefit is seen from quinine found either in tonic water or over-the-counter preparations. An effort should be made to keep the dose as low as possible due to potential hematological side effects (e.g., hemolysis, thrombocytopenia).
Education and counseling of the patient with chemotherapy-induced PN is very important since they could be experiencing a chronic long-term change of daily functioning. Two areas that can directly impact this adjustment include physical and occupational therapy as discussed above.
In addition to the medications and therapies used for treatment of chemotherapy-related PN, researchers are investigating drugs that are able to prevent the nerve damage from occurring altogether. These drugs are called neuroprotective agents.
Neuroprotective agents work in two ways:
- They protect the nerve cells from the toxic effects of chemotherapy
- They promote regeneration of nerve cells without promoting tumor growth.
These drugs include:
- Thiol drugs containing sulfur
- Lipoic acid (comes as an oral supplement which has been used in Europe)
- Amifostine - may be particularly effective for prevention of PN from platinum-based drugs. This drug was approved by the FDA for reducing renal toxicity during the administration of cisplatin and may also have neuroprotective properties.
Neurotrophic agents or nerve growth factors (NGF) work by ensuring the survival of neurons. Limited studies have shown that NGF decreases or disappears after administration of chemotherapy. Some clinical trials have shown that patients with diabetic neuropathy and HIV induced neuropathy exhibited improved function of small-fiber sensory nerves and reduction of pain intensity following administration of rhNGF. Trials are ongoing.
Pyrimidine isaxonine - this drug shows properties for enhancing regeneration of peripheral nerves but has side effects including hepatic toxicity which presently limits its clinical use.