Tag: Dosage

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Does Gabapentin Help Treat Nerve Pain? Max Dosage: 3600 mg per day

Gabapentin can help relieve nerve pain in some people with postherpetic neuralgia (nerve pain after shingles) and peripheral diabetic neuropathy (nerve pain in the feet in people with diabetes). A Cochrane review reported that 3 to 4 patients out of every 10 with either of these conditions experienced at least a 50% reduction in pain intensity when prescribed gabapentin at dosages of 1800mg-3600 mg/day (gabapentin encarbil: 1200mg-3600 mg/day). This compared with only 1 or 2 out of every 10 given a placebo (an inactive treatment). People who had an improvement in pain relief with gabapentin are also expected to experience an improvement in sleep, fatigue, and in their mood.

This same Cochrane review reported that over half of those treated with gabapentin did not experience any worthwhile pain relief, but did experience side effects.

What type of nerve pain is gabapentin approved to treat?

Gabapentin is approved to treat nerve pain (neuralgia) that results from nerve damage. Gabapentin may be used to treat:

  • Nerve pain caused by a herpes zoster viral infection, also known as shingles. This pain is called post-herpetic neuralgia (PHN), and it can be severe and chronic
  • Nerve pain as a result of diabetic neuropathy, which happens when nerves in the feet damaged by diabetes cause chronic burning pain.

How does gabapentin work in nerve pain?

The exact way that gabapentin works to relieve pain is not known. It may change the way the body senses and reacts to pain. Gabapentin is used to manage long-term (chronic) pain, not to be taken for pain as needed. Chronic pain can interfere with sleep and work, and lead to depression.

How quickly does gabapentin work?

Studies show that pain relief may start within one week and reach a maximum effect in about 4 weeks. It can take this long because gabapentin is usually started at a low dose and gradually increased over time until it works.

For treating neuralgia, gabapentin is often started at 300 mg per day and gradually raised by 300 mg per day. One 2017 review of 37 studies found that pain relief usually occurs at a dose of 1,200 mg or more.

The same review compared gabapentin to an inactive medicine (placebo) in almost 6,000 adults with chronic pain from PHN or diabetic neuropathy. Study participants were given either gabapentin or a placebo for 4 to at least 12 weeks. The results showed that 30-40% of people taking gabapentin were able to reduce their pain by half or more, compared to 10-20% of people taking the placebo.

Although some people may get significant relief, others may have side effects without relief of pain. More than half of people taking gabapentin did not get significant relief and had side effects from the drug.

According to the review, about 60% of people taking gabapentin had side effects, including:

  • Dizziness
  • Sleepiness
  • Water retention (edema)
  • Clumsiness while walking (ataxia)

It does not typically make pain worse: In trials comparing gabapentin side effects to placebo side effects, only 1% of people reported increased pain, and this was the same for gabapentin and placebo.

Once you find the dose that relieves neuralgia for you, it is important not to stop taking it suddenly. Stopping suddenly can lead to withdrawal symptoms such as:

  • Anxiety
  • Insomnia
  • Nausea
  • Pain
  • Sweating

Gabapentin is highly lipophilic but not bound to plasma proteins, showing linear pharmacokinetics and not demonstrating any significant protein binding or liver metabolization. It has an oral bioavailability of greater than 90%, independent of dose. Generally, patients achieve steady-state plasma levels within 24 to 48 hours. There is no clinically significant effect in administration with food nor on the extent of absorption or elimination. The elimination half-life of the drug is approximately 6.5 hours. Gabapentin readily crosses the blood-brain barrier. It is primarily excreted renally, with no active metabolites. Dosage adjustment is necessary for patients with renal impairment. Pregabalin does not induce or inhibit CYP enzymes. Also, none of the CYP enzyme inhibitors alter its pharmacokinetics as a consequence.

  • Initial treatment with gabapentin is usually started with one dose of 300 mg per day and later increases the frequency to 3 times a day and dosage up to 4800 mg per day. The recommendation is to start the first dose in the evening and then take the drug three times a day.
  • Usually, the effects are apparent in the first week of treatment but sometimes take about a month for significant improvement.
  • Taper the dose over more than seven days to discontinue the medication.

For Partial Seizure

  • 300 to 1200 mg 3 times per day by mouth
  • Max: 3600 mg per day 

For Post-Herpetic Neuralgia

  • 300 to 600 mg 3 times per day by mouth
  • Max: 1800 mg per day

For Neuropathic Pain

  • 300 to 1200 mg 3 times per day by mouth
  • Max: 3600 mg per day

For Fibromyalgia

  • 400 to 800 mg 3 times per day by mouth
  • Max: 2400 mg per day

Renal Dosing

Adjust the dose amount and frequency.

  • Creatinine clearance of 30 to 60: 200 to 700 mg twice per day
  • Creatinine clearance of 16 to 29: 200 to 700 mg once daily
  • Creatinine clearance of 15: 100 to 300 mg once daily
  • Creatinine clearance of less than 15: 125 to 350 mg as a supplement
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What is the Maximum Daily Dosage of Gabapentin?

I’m taking 800mg three times a day for anxiety. It works great. The max recommended dose is 3600mg daily, but I’ve read where some people take up to 4800mg a day. I guess it depends on the person and how they metabolize it.

Take this medicine only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. To do so may increase the chance of side effects.

This medicine comes with a Medication Guide. Read and follow the instructions carefully. Ask your doctor if you have any questions.

If you are using Gralise® tablets:

  • These should be taken with the evening meal.
  • Swallow the tablet whole. Do not crush, break, or chew it.

For patients with epilepsy who take gabapentin three times per day, do not allow more than 12 hours to pass between any 2 doses. The medicine works best if a constant amount is in the blood.

Neurontin® capsules, tablets, and solution may be taken with or without food.

You may break the scored Neurontin® tablets into two pieces, but make sure you use the second half of the tablet as the next dose. Do not use the half-tablet if the whole tablet has been cut or broken after 28 days. Ask your doctor or pharmacist if you have any questions.

Swallow the capsule whole with plenty of water. Do not open, crush, or chew it.

Measure the oral liquid using a marked measuring spoon, oral syringe, or medicine cup. The average household teaspoon may not hold the right amount of liquid.

If you take an antacid that contains aluminum or magnesium, wait at least 2 hours before taking gabapentin. Some examples of these antacids are Di-Gel®, Gaviscon®, Gelusil®, Maalox® and Mylanta®.

Only use the brand of this medicine that your doctor prescribed. Different brands may not work the same way.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor’s orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage forms (capsules, liquid, and tablets):
    • For epilepsy:
      • Adults and children 12 years of age and older—At first, 300 milligrams (mg) three times per day. Your doctor may adjust your dose as needed and tolerated. However, the dose is usually not more than 1800 mg per day (600 mg three times per day).
      • Children 3 to 11 years of age—Dose is based on body weight and must be determined by your doctor. The starting dose is 10 to 15 milligrams (mg) per kilogram (kg) of body weight per day and divided in 3 doses. Your doctor may adjust your dose as needed and tolerated.
      • Children younger than 3 years of age—Use and dose must be determined by your doctor.
    • For postherpetic neuralgia:
      • Adults— At first, 300 milligrams (mg) as a single dose in the evening. Your doctor may adjust your dose as needed and tolerated. However, the dose is usually not more than 1800 mg per day.
      • Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

You should store the Neurontin® oral liquid in the refrigerator. Do not freeze.

Although the FDA says 3600mg/day in most places, they have a more extensive doc about gabapentin/neurontin usage and bioavailability. First, your body can only process a certain amount taken and the rest is excreted, so large doses over their bioavailablity chart don’t give larger effects.

Lyrica and other meds have different bioavailability, so use smaller dosages. Since your kidneys do much of the work with gaba/neurontin, you want to make sure you do not have any kidney problems.

A person may need lower doses or not use it due to that. Second, calcium channel meds like gabapentin are nonlinear, so side effects and benefits vary from person to person.

What works or doesn’t work for one, may be the opposite for another. That is why dosage benefits and side effects vary so much from person to person. Even a small dose might make you sleep, but not to another person.

I have heard from some people their doc may prescribe smaller doses during the day and a larger dose at the time of day more problems appear such as at night.

Gaba/neurontin has a short half life so needs doses spread out during the day. One challenging thing is that people that are on gaba are also on other meds too, so there is going to be confusion about what caused what and if there are interactions.

After a couple years, I was only on gaba. For me on maximum dose, I did sleep more, plus several other side effects. It all comes down to finding the most benefit with the least negatives including cost or as docs say, benefits outweigh the risks. Suggest reading more of this forum for a patient viewpoint.