The Role of Gabapentin in Pain Management

Opioids, non‐steroidal anti‐inflammatory drugs (NSAIDs), antidepressants, and anticonvulsants are used as pharmacological agents to treat pain. However, no single class of drugs has been found to be effective in all types of pain, presumably because pain syndromes involve different mechanisms.

In addition, each of the currently available drugs is associated with adverse effects, some of which are potentially serious or life‐threatening such as idiosyncratic or toxic reactions.

Traditionally, the treatment of neuropathic pain has involved anticonvulsants, such as carbemazepine, valproic acid and phenytoin, and tricyclic antidepressants, such as amitriptyline and nortriptyline and doxepin. The main disadvantages of the anticonvulsants are their potential for drug interactions via the induction of hepatic enzymes, or resulting from inhibition of hepatic enzymes by other drugs. Minor side‐effects such as sedation, ataxia, vertigo and diplopia are associated with carbemazepine and phenytoin, whereas, anorexia, nausea, vomiting and tremor are associated with valproic acid. Chronic phenytoin use may cause peripheral neuropathy (30%) and gingival hyperplasia (20%), and fetal hydantoin syndrome if administered during pregnancy. Carbemazepine can cause chronic diarrhoea or the syndrome of inappropriate ADH secretion, and rarely aplastic anaemia, thrombocytopaenia, hepatocellular jaundice and cardiac arrhythmias.

Tricyclic antidepressants also cause side‐effects that can be troublesome or potentially dangerous, such as anticholinergic effects (dry mouth, blurred vision, urinary retention, ileus), sedation, orthostatic hypotension, tachycardia and atrio‐ventricular conduction disturbances. Such adverse effects are likely to reduce the tolerance of this group of drugs in elderly or unwell patients. Some subgroups of patients with painful neuropathy such as diabetes may also have autonomic neuropathy and may not tolerate the orthostatic hypotension associated with tricyclic antidepressants.

With increasing evidence of the efficacy of gabapentin in a wide variety of pain syndromes, especially neuropathic pain, gabapentin may be potentially useful because of its relative freedom from serious adverse effects, its lack of interactions with other drugs and its lack of potential for causing drug dependence.

A comparison of the evidence available of efficacy and toxicity for anticonvulsants (gabapentin, phenytoin and carbemazepine) and antidepressants (tricyclic antidepressants and SSRIs) in patients with diabetic neuropathy and postherpetic neuralgia has recently been made by Collins et al. [129] These two neuropathic pain conditions were chosen according to strict diagnostic criteria. Although two previous systematic reviews of anticonvulsants and antidepressants in diabetic neuropathy showed no significant difference in efficacy or adverse effects between the two drug classes [130, 131], Collins et al. found that when data from randomised controlled trials for both diabetic neuropathy and postherpetic neuralgia were pooled, the NNT for at least 50% pain relief was identical for both classes of drugs. When gabapentin was compared with other anticonvulsants, there was no significant difference in efficacy.

The NNT for gabapentin was 3.4 compared with 2.2 for phenytoin/carbemazepine. The number needed to harm (NNH, defined as the number needed to harm one patient from the therapy) for minor adverse effects was 2.7 for both antidepressants and anticonvulsants. Collins et al. used two trials to provide data on minor adverse effects for gabapentin and two trials for phenytoin. The NNH (minor adverse effects) was 2.6 similar to that of gabapentin and 3.2 for phenytoin. The NNH (major adverse effects) for the tricyclic antidepressants was 17, and no significant difference in the incidence of major adverse effects was found between anticonvulsants and placebo.

Collins et al. suggested that the difference in the incidence of major adverse effects can be compared by using the ratio between treatment specific benefit and treatment specific harm (defined as the number of patients needed to experience at least 50% benefit for one to experience a major adverse effect that warranted discontinuation of treatment). The ratio for gabapentin was 6 compared with an average of 8 for all anticonvulsants, and 6 for all antidepressants. As adverse data were pooled from both diabetic and postherpetic neuralgia studies, methodological factors and heterogenicity in these data may limit the validity and robustness of these ratios. The spectrum of the pain and short study duration tend to underestimate the treatment effect, whereas the small sample size of the studies overestimate the treatment effect.

The above evidence suggests that gabapentin is as efficacious at treating neuropathic pain with no significant difference in minor adverse effects and a low propensity for serious adverse effects compared with other anticonvulsants and antidepressants. Therefore, gabapentin is a useful agent in the multimodal approach in the management of neuropathic pain.

Adverse Reactions in Pooled Placebo-Controlled Trials in Postherpetic Neuralgia

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Postherpetic Neuralgia

The most common adverse reactions associated with the use of NEURONTIN in adults, not seen at an equivalent frequency among placebo-treated patients, were dizziness, somnolence, and peripheral edema.

In the 2 controlled trials in postherpetic neuralgia, 16% of the 336 patients who received NEURONTIN and 9% of the 227 patients who received placebo discontinued treatment because of an adverse reaction. The adverse reactions that most frequently led to withdrawal in NEURONTIN-treated patients were dizziness, somnolence, and nausea.

Following table lists adverse reactions that occurred in at least 1% of NEURONTIN-treated patients with postherpetic neuralgia participating in placebo-controlled trials and that were numerically more frequent in the NEURONTIN group than in the placebo group.

TABLE 3. Adverse Reactions in Pooled Placebo-Controlled Trials in Postherpetic Neuralgia
NEURONTIN
N=336
%
Placebo
N=227
%
Reported as blurred vision
Body as a Whole
  Asthenia 6 5
  Infection 5 4
  Accidental injury 3 1
Digestive System
  Diarrhea 6 3
  Dry mouth 5 1
  Constipation 4 2
  Nausea 4 3
  Vomiting 3 2
Metabolic and Nutritional Disorders
  Peripheral edema 8 2
  Weight gain 2 0
  Hyperglycemia 1 0
Nervous System
  Dizziness 28 8
  Somnolence 21 5
  Ataxia 3 0
  Abnormal thinking 3 0
  Abnormal gait 2 0
  Incoordination 2 0
Respiratory System
  Pharyngitis 1 0
Special Senses
  Amblyopia 3 1
  Conjunctivitis 1 0
  Diplopia 1 0
  Otitis media 1 0

Other reactions in more than 1% of patients but equally or more frequent in the placebo group included pain, tremor, neuralgia, back pain, dyspepsia, dyspnea, and flu syndrome.

There were no clinically important differences between men and women in the types and incidence of adverse reactions. Because there were few patients whose race was reported as other than white, there are insufficient data to support a statement regarding the distribution of adverse reactions by race.

 

What should you know before you buy gabapentin Online

Gabapentin (Generic Neurontin ) was developed to treat epilepsy, but it is now used to treat various forms of chronic pain. It works by reducing the number of signals sent through the nerves. If the signals are reduced then the pain will be reduced. Research has shown that Gabapentin can help in treating various types of nerve pain.

Some Research Team performed searches to look for clinical trials where gabapentin was used to treat neuropathic pain or fibromyalgia. They found that 5633 participants had been involved in 37 studies of reasonable quality.  They tested gabapentin against placebo for four weeks or more.  Studies lasting only one or two weeks are unhelpful when pain can last for years.

Neuropathic pain is pain coming from damaged nerves. It differs from pain messages carried along healthy nerves from damaged tissue (a fall, cut, or arthritic knee). Neuropathic pain is treated by different medicines than pain from damaged tissue.

Medicines like paracetamol or ibuprofen are not effective in neuropathic pain, while medicines that are sometimes used to treat depression or epilepsy can be very effective in some people with neuropathic pain.  Our understanding of fibromyalgia (a condition of persistent, widespread pain and tenderness, sleep problems, and fatigue) is poor, but fibromyalgia can respond to the same medicines as neuropathic pain.

Gabapentin is helpful for some people with chronic neuropathic pain or fibromyalgia. Gabapentin comes as a capsule, tablet, or solution. You take it by mouth. Gabapentin is available as the brand-name drugs Neurontin, Gralise, and Horizant.  It’s also available as a generic drug.

It is very important that your doctor check your progress at regular visits, especially in the first few months if you have epilepsy. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it.

These may be cause serious allergic reactions that may involve multiple organs, such as your liver or kidneys. Check with your doctor right away if you or your child have more than one of the following symptoms: fever, rash, swollen, painful, or tender lymph glands in the neck, armpit, or groin, unusual bleeding or bruising, or yellow eyes or skin.

Gabapentin may cause vision changes, clumsiness, unsteadiness, dizziness, drowsiness, sleepiness, or trouble with thinking. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert, well-coordinated, or able to think or see well. If these side effects are especially bothersome, check with your doctor.

This medicine may cause some people to be agitated, irritable, or display other abnormal behaviors, such as feeling sad or hopeless, getting upset easily, or feeling nervous, restless, or hostile. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. If you, your child, or your caregiver notice any of these side effects, tell your doctor right away.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for hay fever, allergies, or colds, sedatives, tranquilizers, or sleeping medicines, prescription pain medicine or narcotics, other medicines for seizures (eg, barbiturates), muscle relaxants, or anesthetics, including some dental anesthetics. Check with your medical doctor or dentist before taking any of the above while you or your child are using gabapentin.

Do not stop using gabapentin without checking with your doctor. Stopping the medicine suddenly may cause seizures. Your doctor may want you or your child to gradually reduce the amount you are taking before stopping it completely.

Make sure any doctor or dentist who treats you knows that you are using this medicine. This medicine may affect the results of certain medical tests.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

 

Gabapentin is also used for Prevention of Fibromyalgia

Fibromyalgia is a muscular condition that affects many people. It refers to muscle fatigue and pain felt across different muscle groups in the body, not just on isolated areas.  Fibromyalgia is a disorder characterized by widespread musculoskeletal pain accompanied by fatigue, sleep, memory and mood issues.

The term fibromyalgia directly means pain that is embedded in the tissues of the muscles, specifically the fibrous tissues.  This very acute pain starts from the ligaments, the tendons, and other such connective muscle tissues that are present all over the muscular system of the body.  Researchers believe that fibromyalgia amplifies painful sensations by affecting the way your brain processes pain signals.

Fibromyalgia Symptoms sometimes begin after a physical trauma, surgery, infection or significant psychological stress. In other cases, symptoms gradually accumulate over time with no single triggering event.

Women are more likely to develop fibromyalgia than are men.  Many people who have fibromyalgia also have tension headaches, temporomandibular joint (TMJ) disorders, irritable bowel syndrome, anxiety and depression.

There are however some controversial theories regarding  Fibromyalgia that propose that this condition is a psychosomatic illness, that is, it is a disorder brought about by psychological factors and not necessarily physical factors. This reasoning is mainly brought about by the strong evidence available that relates Fibromyalgia to major depression.

An in-depth review regarding the association of major depression disorders with Fibromyalgia brought out significant similarities between the two in terms of psychological characteristics and neuroendoctrine abnormalities in the patients.

Researchers believe repeated nerve stimulation causes the brains of people with fibromyalgia to change. This change involves an abnormal increase in levels of certain chemicals in the brain that signal pain (neurotransmitters). In addition, the brain’s pain receptors seem to develop a sort of memory of the pain and become more sensitive, meaning they can overreact to pain signals.

Medications designed to treat epilepsy are often useful in reducing certain types of nerve pain. Gabapentin (Neurontin) is sometimes helpful in reducing fibromyalgia symptoms.  Gabapentin is a medicine used to treat pain caused by nerves that are not working properly.   Gabapentin changes the way that the nerves send messages to the brain. It can be taken in a tablet or a liquid, with or without food.  Doses are usually 1200 mg to 2400 mg each day. At the start of treatment low doses are used to minimise side effects, but the dose is usually increased after a few weeks.

At the reviews of gabapentin for fibromyalgia in drugs.com ,  almost 70% Fibromyalgia Patients think Gabapentin can cure their fiobromyalgia disease.  But almost 20% fiobromyalgia Patients think it doesnot work. ( Rating 1 -2 %),  another 15% patients think it do work but the effect is not that good ( Rating 3 – 5 ).

One of the patient said:

“I have had fibro for 7 years, finally have a doctor that prescribed me Gabapentin. It’s amazing I feel like a normal person again. I sleep through the night, with no pain anymore. My anxiety is gone also, which is awesome. I know everyone is different, but it works for me. I have had little to no side effects yet. First few doses was a bit of an air head other than that no complaints. Being able to function pain free and agitation free is a blessing.”

Another Fiobro patient said:

“I had the best results, in relieving the pain, with gabapentin. I was able to work through the other symptoms. The etodolac helped with the inflammation. I was doing well, until the muscle spasms started, again. I suspect the mould allergies exasperated the symptoms. So, cyclobenzeprine was added. I don’t know what happened, but I was jobless, homeless, and very sick by the time a CVS pharmacist recognized the V.A. had put me on another toxic, prescription drug cocktail. When I brought it to the V.A.s attention, as usual, it was ignored. The medications that help, are the ones the V.A. will not prescribe to veterans like myself. They say speak up, if you do, expect to be classified as mentally ill, violent, aggressive, involuntarily committed”

NatalieW555 Said:
“I was suffering from fibromyalgia pain most of my adult life, I’m 52 by the way, not realizing there was this wonderful medication available to me…I started it about 2 years ago and it really makes a HUGE difference in how my body feels. I take 300 mg 3X daily. I hope it never quits working for me…you should give it a try….It has no side effects on me.”

Member Annabqnm Said:

“Pretty much saved my life. 13 years ago fibromyalgia symptoms (severe pain especially legs and shoulders), started. My father was taking high doses of gabapentin for chronic guillaune barre. He urged me to try it–and it was the first real sleep I had in months! My rheumatologist had me on 1600mg. 3x, gradually lowered to 1600 mg. 2x. Studies at Mayo Clinic and Johns Hopkins show very few (and very mild) side effects, even at high doses. The only problem I have is if I forget to take them. Then I get flu like symptoms. I was able to continue my career (elementary school teacher) with no problems. Retired this year age 66 and very active. BTW my memory seems better than most friends my age.”

But 30% Fibro customers think Gabapentin is not effective for their Fibro disease. I looked the reviews they have wrote, I found most of them are just back pain or leg pain but not Fiobromyalgia. But some Fibro patients do think it has some side effects, especially thought problems such as depression.

One of the Fibro patient said:

“I have “fibromyalgia,” severe muscle pain from a twisted spine/congenitally deformed vertebrae. I was getting better with yoga, but hurt my back/rib muscles overdoing. I developed depression on gabapentin after a few weeks. At first it dulled the pain and made me feel lightheaded, and I had memory problems. Then my anxiety increased and the pain continued, and hit a real low. I spent two weeks in a psych ward until a brilliant psych nurse who believed in treating muscle pain. I am now recovering on a mix of robaxin, a muscle relaxer, a low dose of valium for rib spasms, and prozac and remeron (for sleep) and hope to get off all of them once I can exercise again. Similar reaction to Lyrica four years ago.”

Gabapentin is effective for Fibro. But you need consider whether you can endure the side effects of gabapentin. Please check our website for the Gabapentin Side Effects.

What you should know before you buy Gabapentin online

Keep these considerations in mind if your doctor prescribes gabapentin oral capsule for you.

Before taking gabapentin,

  • tell your doctor and pharmacist if you are allergic to gabapentin, any other medications, or any of the inactive ingredients in the type of gabapentin you plan to take. Ask your pharmacist for a list of the inactive ingredients.
  • you should know that gabapentin is available in different forms that may be prescribed for different uses. Ask your doctor to be sure that you are not taking more than one product that contains gabapentin.
  • tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: antidepressants; antihistamines; medications for anxiety; medications that make you feel dizzy or drowsy; medications for mental illness; naproxen (Aleve, Anaprox, Naprosyn, others); opioid (narcotic) medications for pain such as hydrocodone (in Hydrocet, in Vicodin, others), morphine (Avinza, Kadian, MSIR, others), or oxycodone OxyContin, in Percocet, in Roxicet, others); sedatives; medications for seizures; sleeping pills, and tranquilizers. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • if you are taking antacids such as Maalox or Mylanta, take them at least 2 hours before you take gabapentin tablets, capsules, or solution.
  • tell your doctor if you have or have ever had lung or kidney disease. If you will be taking the extended-release tablets, also tell your doctor if you need to sleep during the day and stay awake at night.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking gabapentin, call your doctor.
  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking gabapentin.
  • you should know that this medication may make you drowsy or dizzy, may slow your thinking, and may cause loss of coordination. Do not drive a car or operate machinery until you know how this medication affects you, and your doctor agrees that it is safe for you to begin these activities.
  • if you are giving gabapentin to your child, you should know that your child’s behavior and mental abilities may change while he or she is taking gabapentin. Your child may have sudden changes in mood, become hostile or hyperactive, have difficulty concentrating or paying attention, or be drowsy or clumsy. Have your child avoid activities that could be dangerous, such as riding a bicycle, until you know how gabapentin affects him or her.
  • remember that alcohol can add to the drowsiness caused by this medication.
  • you should know that your mental health may change in unexpected ways and you may become suicidal (thinking about harming or killing yourself or planning or trying to do so) while you are taking gabapentin for the treatment of epilepsy, mental illness, or other conditions. A small number of adults and children 5 years of age and older (about 1 in 500 people) who took anticonvulsants such as gabapentin to treat various conditions during clinical studies became suicidal during their treatment. Some of these people developed suicidal thoughts and behavior as early as one week after they started taking the medication. There is a risk that you may experience changes in your mental health if you take an anticonvulsant medication such as gabapentin, but there may also be a risk that you will experience changes in your mental health if your condition is not treated. You and your doctor will decide whether the risks of taking an anticonvulsant medication are greater than the risks of not taking the medication. You, your family, or your caregiver should call your doctor right away if you experience any of the following symptoms: panic attacks; agitation or restlessness; new or worsening irritability, anxiety, or depression; acting on dangerous impulses; difficulty falling or staying asleep; aggressive, angry, or violent behavior; mania (frenzied, abnormally excited mood); talking or thinking about wanting to hurt yourself or end your life; withdrawing from friends and family; preoccupation with death and dying; giving away prized possessions; or any other unusual changes in behavior or mood. Be sure that your family or caregiver knows which symptoms may be serious so they can call the doctor if you are unable to seek treatment on your own.

Refill

You are only allowed to buy gabapentin online when you refill and you have taken gabapentin before. It means your local doctors have already prescribed you Gabapentin in the past.

Complete the health questionnaires very carefully

your online doctors only know you by your questionnaires. please complete the form very carefully.

General

Gabapentin oral capsules can be taken with or without food. Taking them with food can help to reduce upset stomach.

Storage

  • Store gabapentin at room temperature between 68°F and 77°F (20°C and 25°C).
  • Don’t store this medication in moist or damp areas, such as bathrooms.

Refills

A prescription for this medication is refillable. You should not need a new prescription for this medication to be refilled. Your doctor will write the number of refills authorized on your prescription.

Travel

When traveling with your medication:

  • Always carry your medication with you, such as in your carry-on bag.
  • Don’t worry about airport X-ray machines. They can’t hurt your medication.
  • You may need to show airport staff the pharmacy label for your medication. Be sure to carry with you the prescription-labeled box that your medication came in.
  • Do not put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Clinical monitoring

Your local doctor will monitor your kidney function.