[tshadow]

The medications that work for the pain of neuropathy fall into a few groups:

Tricyclics (e.g, amitriptyline/elavil, nortriptyline, desipramine/norpramin). These drugs were originally used as anti-depressants, typically at much higher doses than are used for treating painful neuropathies. They probably work by blocking norepinephrine receptors. They are usually taken once a day, an hour or so before sleep, as they are slowly metabolized (thus taken once/day) and often cause some degree of drowsiness/sedation (and thus are taken before sleep). The drowsiness is often a useful side effect when pain interferes with sleep. One typically starts with a low dose (25 mg or even 10 mg) and "builds up" the dose until either a good effect has been achieved or there are intolerable side effects (typically 50-100 mg). Beside drowsiness, a dry mouth and cognitive side effects are common (and there are other side effects, too). It is important to know that the tricyclics typically take 2-4 weeks to reach their full effectiveness against pain, and that the severity of the side effects often diminishes over time.

Neurontin (gabapentin). This medication is not approved for the treatment of chronic pain, but is probably more widely used for this reason than for the treatment of its approved indication, epilepsy. It was designed to be long-lasting mimic of a neurotransmitter, GABA. Neurontin comes in 100, 200, and 300 mg capsules; these are taken every 6-8 hours (the dose to be determined by its efficacy and side effects!). Cognitive changes are the most common side effect. In my experience, Neurontin works less reliably than do the tricyclics.

Narcotics. The keys for using narcotics are matching the duration of action to the duration of pain, and letting the patient figure out the dose that provides adequate pain relief with acceptable side effects. There are a few kinds of long acting narcotics:

MS Contin (the active ingredient is morphine; 15, 30, 60, 100 mg tablets); works for about 12 hours.
Oxycontin (the active ingredient is oxycodone; 10, 20, 40 mg tablets); works for about 12 hours.
Duragesic patches (the active ingredient is fentanyl; comes in 10cm2/2.5 mg, 20cm2/5.0 mg, 30cm2/7.5 mg, and 40cm2/10 mg size patches); works for 2-3 days/patch.
There are many kinds of short acting ones. (I often use the regular form of oxycodone, which lasts 3-4 hours.) I typically ask patients to use both long acting narcotics on a regular schedule (usually every 8 hours) to treat the constant pain, and use a short-acting one for "break-through" pain (the episodes of pain that are not "covered" by the long-acting narcotic. When pain is worse during a particular time of the day (late afternoon to early evening), I recommend using oxycodone (for 2-3 hours of relief) or oxycontin/MS contin (for 8 hours of relief), depending on the duration of that period. Like tricylics, narcotics cause drowsiness, and have other side effects, too (constipation, for one). Tricyclics and narcotics often work well together for pain relief (tricyclics "potentiate" the pain relief of narcotics).

Tegretol (carbamazepine). This medication is not approved for the treatment of chronic pain, but is probably more widely used for this reason than for the treatment of its approved indication, epilepsy. Tegretol works by blocking voltage-gated sodium channels. In my experience, Tegretol works only sometimes. Tegretol comes in 100 and 200 mg tablets that are taken every 6 hours. A sustained released form (Tegretol XR) comes in 100, 200, and 400 mg tablets; these are taken every 12 hours.

Anti-inflammatories. There are basically two kinds of anti-inflammatory medications—corticosteroids (these are different than the performance-enhancing "steroids" used by atheletes) and non-steroidal anti-inflammatory drugs (NSAIDs).

Prednisone, prednisolone, and decadron are examples of corticosteriods. These drugs are used for the long-term treatment of some chronic inflammatory conditions, but are more commonly used for short-term conditions. Corticosteroids should not be used to treat painful neuropathies, unless the underlying cause of the neuropathy is an inflammatory condition.

There are many NSAIDs, including the following:

Aspirin, including Ecotrin. Aspirin or other salicylates are an active ingredient in many combination medications, including Excedrin, Disalcid.
There are many newer NSAIDs - Anaprox/naproxen, Clinoril, Daypro, Feldene, Indocin/indomethacin, Lodine, Motrin/ibuprofen, Naprosyn, Orudis, Relafen, Tolectin, Toradol/ketoprofen, Voltaren.
The newest NSAIDs are the COX1 inhibitors. (Vioxx has been removed from the market, however, and Celebrex has a number of potentially harmful side effects.)
Aspirin, and NSAIDs are not effective for the treatment of the pain of neuropathy, but they do work on radicular pain (caused by "pinched nerves") as well as arthritis, tendonitis, and a host of other conditions.