Neuropathic Cancer Pain: The Role of Adjuvant Analgesics

Neuropathic Cancer Pain: The Role of Adjuvant Analgesics

The article by Drs. Farrar and Portenoy reviews the
definition, clinical characteristics, mechanisms, and analgesic medication
options for neuropathic pain associated with cancer or its treatment. The
authors have succinctly summarized decades of clinical research in what has
grown into an enormously complex area.

There is indeed a dizzying array of analgesic options available for the
treatment of cancer-related neuropathic pain (about 50 drugs are listed in the
article). Many agents are described as having wide dose ranges, with up to a
40-fold difference between the lowest and highest effective dose. Seven
different routes of drug administration are mentioned in the article, and many
clinicians would add even more to that list.

This information, though complex, can be even more challenging to apply: Most
analgesic drugs will need to be slowly dosed upward until pain relief or drug
toxicity occurs. If toxicity develops without adequate pain relief, the first
drug should be tapered, another adjuvant should be selected, and the upwards
titration process repeated. Indeed, the key to successful application of
adjuvant analgesics in cancer-related neuropathic pain often requires patience
and endurance on the part of both the patient and physician in undergoing
sequential and often toxic trials of analgesics.

Therein lies the art of neuropathic cancer pain management: which drug, for
which patient, at which dose, and for how long?

Guideposts for managing neuropathic pain often lie hidden within the patient’s
clinical presentation, and a brief attempt to summarize some of this information

The Patient’s History

The patient’s history can help to elucidate the complex tapestry of pain
that contributes to the overall experience of cancer-related neuropathic pain.
Irrespective of the mechanism, neuropathic pain is often experienced as a blend
of three different variations: (1) steady and burning; (2) sudden, stabbing, and
brief ("neuralgic"); and (3) hurts with light touch ("allodynia").
For steady pain, an opioid or a tricyclic is often prescribed; for neuralgic
pain, either carbamazepine or gabapentin (Neurontin) is administered; and for
allodynia, a topical local anesthetic cream or hot pepper cream is generally
applied, with or without concurrent administration of an oral tricyclic.


Loading comments...
