Brand & Generic Names; Drug Classes
|US brand name: Neurontin|
|Generic name: gabapentin|
|Primary drug class: Antiepileptics/Anticonvulsants|
|Additional drug class(es): Migraine/NeuropathicPain|
Approved & Off-Label Uses (Indications)
Neurontin’s US FDA Approved Treatment(s)
- As an add-on to treat partial epileptic seizures in adults and children. (IR Neurontin only)
- Postherpetic neuralgia (AKA herpes zoster, AKA shingles, AKA the reason why parents shouldn’t buy into anti-vaccination paranoia and take their children to chicken pox parties). (Both IR Neurontin and ER Horizant)
- Restless Leg Syndrome (RLS) (ER Horizant only)
Uses Approved Overseas but not in the US
Off-Label Uses of Neurontin
What isn’t Neurontin used for? Sometimes Neurontin is a valid therapy for the following, and sometimes it is utter quakery and placebo. There was one big-ass settlement against Parke-Davis (acquired by Warner Lambert, acquire by Pfizer) for their pushing Neurontin on doctors for inappropriate uses. So remember to check on who paid for the studies in question, as it will tends to make the results more favorable for the company paying for it (on average 3.6 times more likely, according to a Yale study).
These are just some of the off-label uses of Neurontin we’re aware of. Let’s start with some that it’s actually good for:
- All sorts of neuropathic pain, including
- Restless Leg Syndrome/PLMD - Note the new extended-release form under the name Horizant has FDA approval to treat RLS, but it is still an off-label application for classic immediate-release Neurontin (gabapentin).
And where it’s a placebo with side effects, albeit a fairly low side effect profile for an AED:
- Bipolar Disorder
- Migraines (although it does work for other types of headaches now and then)
- Sleep Disorders
- MS (It tests a little better than placebo, putting it in last-straw territory)
- Chronic Fatigue. But what isn’t used for chronic fatigue?
- Menopausal Symptoms
- Cocaine Abuse
- And probably a bunch of stuff I don’t even know about. Maybe it’s quite useful in these applications, sometimes it’s prescribed first just because it’s an AED/anticonvulsant with a very low side effect profile and doctors are sick and tired of people whining about both their vague symptoms and how medication-sensitive they are.
When & If Neurontin Will Work
Neurontin’s Usual Onset of Action (when it starts working)
It should start to do something for you a couple days after you reach 900mg a day. But because of the whole bioavailability issue it may not be until you’re somewhere in the range of 900–1800mg a day, presuming it will do anything at all for you.
Likelihood of Working
Postherpetic Neuralgia, Neuropathy and Neuropathic Pain
Neurontin, and its cousin Lyrica, are better pain meds than they are AEDs. Neurontin is actually a pretty good med when it comes to shingles and other incredibly painful conditions. If your pain is caused by your nerves and not by inflammation or something else that isn’t obvious, the odds are somewhere in the 2 out of 3 to 3 out of 4 range that Neurontin will have some positive effect. It may or may not be enough, but if it does something more than give you the stupids, at least you and your doctor will have a good idea that your pain is neuropathic in origin. So if you weren’t sure of its origin, that’s a hell of a lot better than nothing.
Anxiety Spectrum Disorders
Neurontin is a decent med for the types of anxiety that respond to benzodiazepines, such as GAD, panic disorders, and agoraphobia. It’s usually not much of a help for OCD. If long-term and/or daily use of a benzo isn’t an option, using Neurontin instead might be worth a shot.
Does anybody still take Neurontin for epilepsy? I haven’t been able to find much in the way of reports from the field that are from this century.
Restless Leg Syndrome
Extended-release Horizant (It lets you remain horizontal? What if you like sleeping in an easy chair?) is too new, and as an off-label application for the classic immediate-release flavor the results were so-so. When Mouse took Neurontin for pain and anxiety - OK for pain, marginally better than anything else for anxiety - it made her RLS so much worse I had to sleep on the couch. She could sleep through it. I have no idea when or if I’ll get back to you with real data on how well it works.
Taking and Discontinuing
How to Take Neurontin
Given all the different things for which Neurontin is used, I’m not about to cover all the possible dosages. I’m just going to cover the FDA-approved applications in adults. For everything else it’s between you and your doctor. Even with the approved stuff it’s going to be between you and your doctor, because I’m more or less OK with the party line. The only real problem I have with the recommendations from the PI sheets is the same problem I have with most meds: target dosages. Other than remaining at the dosage where your symptoms stop and raising it only when you need to, I’m good with everything else.
“divided BID” and “divided TID” mean “take two times daily” and “take three times daily”. See our page on terms, abbreviations, acronyms & initialisms for more information.
In adults with postherpetic neuralgia, Neurontin therapy may be initiated as a single 300-mg dose on Day 1, 600 mg/day on Day 2 (divided BID), and 900 mg/day on Day 3 (divided TID). The dose can subsequently be titrated up as needed for pain relief to a daily dose of 1800 mg (divided TID). In clinical studies, efficacy was demonstrated over a range of doses from 1800 mg/day to 3600 mg/day with comparable effects across the dose range. Additional benefit of using doses greater than 1800 mg/day was not demonstrated. —Neurontin PI sheet
Depending on how much pain you’re in, the rate the dosage is increased (titration) in Pfizer’s recommendation is too fast, too slow, or just right. As with any crazy med, you should stop increasing your dosage when your symptoms stop, and remain at that dosage until you need to raise it. So if Neurontin works for you at 600mg a day, then stay there. See Interesting Stuff for why dosages of 1800mg a day for anything are a waste of money and side effects.
The recommended dosage of HORIZANT is 600 mg twice daily. HORIZANT should be initiated at a dose of 600 mg in the morning for 3 days of therapy, then increased to 600 mg twice daily (1,200 mg/day) on day four. In the 12-week principal efficacy study, additional benefit of using doses greater than 1,200 mg a day was not demonstrated, and these higher doses resulted in an increase in adverse reactions. If the dose is not taken at the recommended time, skip this dose, and the next dose should be taken at the time of the next scheduled dose. —Horizant PI sheet
The folks at XenoPort are a bit more in tune with the concept of gradual titration. They make a 300mg tablet, so you have even more options. As with IR Neurontin, it all depends on how much it hurts.
The effective dose of Neurontin is 900 to 1800 mg/day and given in divided doses (three times a day) using 300 or 400 mg capsules, or 600 or 800 mg tablets. The starting dose is 300 mg three times a day. If necessary, the dose may be increased using 300 or 400 mg capsules, or 600 or 800 mg tablets three times a day up to 1800 mg/day. Dosages up to 2400 mg/day have been well tolerated in long-term clinical studies. Doses of 3600 mg/day have also been administered to a small number of patients for a relatively short duration, and have been well tolerated. The maximum time between doses in the TID schedule should not exceed 12 hours. —Neurontin PI sheet
Yeah, sure. Who takes Neurontin for epilepsy any more?
The recommended dosage for HORIZANT is 600 mg once daily at about 5 PM. A daily dose of 1,200 mg provided no additional benefit compared with the 600-mg dose, but caused an increase in adverse reactions. If the dose is not taken at the recommended time, the next dose should be taken the following day as prescribed. —Horizant PI sheet
I can’t think of another med with a specific time of day to take it. I need to dig into the PK, clinical trials, and assorted other data to figure out what the hell that’s about. The first thing I think of, though, is it’s something like Aplenzin’s dosages (scroll way down).
How to Stop Taking Neurontin (discontinuation / withdrawal)
Because Neurontin is an AED I used to be as paranoid about it as other AEDs. Now I think you should only worry about discontinuing too quickly if you’re epileptic or have other seizure risk factors (recently stopped drinking heavily, have an anorectic eating disorder, etc.), and you are taking a pro-convulsant like lithium, Wellbutrin, or a stimulant, and/or your are not taking another AED. Simple, right? In any event, reducing your dosage by 600mg each week (as Pfizer and XenoPort recommend) or 300mg every 3 to 4 days (as I suggest) is unlikely to give most people any problems.