Gabapentin mechanism of action

Gabapentin was designed to mimic the neurotransmitter GABA.

It does not, however, bind to GABA receptors. Its mechanism of action as an antiepileptic agent likely involves its inhibition of the alpha 2-delta subunit of voltage-gated calcium channels .

It was first approved as an anticonvulsant in 1994 in the US and is now available worldwide. It was also approved in the US for postherpetic neuralgia in 2002 and is used commonly to treat neuropathic pain. Gabapentin is renally excreted and is not an enzyme-inducing anticonvulsant.

Gabapentin use resulted in increased fracture in the Canadian population-based study . There is limited study on effects of gabapentin on BMD. Several studies have evaluated adults taking anticonvulsant that included gabapentin. These data suggest that gabapentin may cause bone loss.

The previously described MrOS study found significant bone loss at the hip in older men prescribed gabapentin . There are no reports evaluating whether gabapentin treatment results in changes in markers of bone and mineral metabolism.

Future studies should focus on whether gabapentin, which is commonly used for multiple indications, adversely affects bone.

Gabapentin and pregabalin are structurally related compounds with recognized efficacy in the treatment of both epilepsy and neuropathic pain. The pharmacological mechanisms by which these agents exert their clinical effects have, until recently, remained unclear.

The interaction of gabapentin and pregabalin with conventional antiepileptic and analgesic drug targets is likely to be modest, at best, and has been largely dismissed in favour of a selective inhibitory effect on voltage-gated calcium channels containing the alpha2delta-1 subunit.

This mechanism is consistently observed in both rodent- and human-based experimental paradigms and may be sufficiently robust to account for much of the clinical activity of these compounds.

The chemical structure of gabapentin (Neurontin) is derived by addition of a cyclohexyl group to the backbone of gamma-aminobutyric acid (GABA). Gabapentin prevents seizures in a wide variety of models in animals, including generalized tonic-clonic and partial seizures.

Gabapentin has no activity at GABAA or GABAB receptors of GABA uptake carriers of brain. Gabapentin interacts with a high-affinity binding site in brain membranes, which has recently been identified as an auxiliary subunit of voltage-sensitive Ca2+ channels.

However, the functional correlate of gabapentin binding is unclear and remains under study. Gabapentin crosses several lipid membrane barriers via system L amino acid transporters. In vitro, gabapentin modulates the action of the GABA synthetic enzyme, glutamic acid decarboxylase (GAD) and the glutamate synthesizing enzyme, branched-chain amino acid transaminase.

Results with human and rat brain NMR spectroscopy indicate that gabapentin increases GABA synthesis. Gabapentin increases non-synaptic GABA responses from neuronal tissues in vitro. In vitro, gabapentin reduces the release of several mono-amine neurotransmitters.

Gabapentin prevents pain responses in several animal models of hyperalgesia and prevents neuronal death in vitro and in vivo with models of the neurodegenerative disease amyotrophic lateral sclerosis (ALS). Gabapentin is also active in models that detect anxiolytic activity.

Although gabapentin may have several different pharmacological actions, it appears that modulation of GABA synthesis and glutamate synthesis may be important.

What is Gabapentin side effects ?

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

      1. Clumsiness or unsteadiness
      2. continuous, uncontrolled, back-and-forth, or rolling eye movements

More common in children

      1. Aggressive behavior or other behavior problems
      2. anxiety
      3. concentration problems and change in school performance
      4. crying
      5. depression
      6. false sense of well-being
      7. hyperactivity or increase in body movements
      8. rapidly changing moods
      9. reacting too quickly, too emotional, or overreacting
      10. restlessness
      11. suspiciousness or distrust

Less common

      1. Black, tarry stools
      2. chest pain
      3. chills
      4. cough
      5. depression, irritability, or other mood or mental changes
      6. fever
      7. loss of memory
      8. pain or swelling in the arms or legs
      9. painful or difficult urination
      10. shortness of breath
      11. sore throat
      12. sores, ulcers, or white spots on the lips or in the mouth
      13. swollen glands
      14. unusual bleeding or bruising
      15. unusual tiredness or weakness

Incidence not known

      1. Abdominal or stomach pain
      2. blistering, peeling, or loosening of the skin
      3. clay-colored stools
      4. coma
      5. confusion
      6. convulsions
      7. dark urine
      8. decreased urine output
      9. diarrhea
      10. dizziness
      11. fast or irregular heartbeat
      12. headache
      13. increased thirst
      14. itching or skin rash
      15. joint pain
      16. large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
      17. loss of appetite
      18. muscle ache or pain
      19. nausea
      20. red skin lesions, often with a purple center
      21. red, irritated eyes
      22. unpleasant breath odor
      23. vomiting of blood
      24. yellow eyes or skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  1. Blurred vision
  2. cold or flu-like symptoms
  3. delusions
  4. dementia
  5. hoarseness
  6. lack or loss of strength
  7. lower back or side pain
  8. swelling of the hands, feet, or lower legs
  9. trembling or shaking

Less common or rare

      1. Accidental injury
      2. appetite increased
      3. back pain
      4. bloated or full feeling
      5. body aches or pain
      6. burning, dry, or itching eyes
      7. change in vision
      8. change in walking and balance
      9. clumsiness or unsteadiness
      10. congestion
      11. constipation
      12. cough producing mucus
      13. decrease in sexual desire or ability
      14. difficulty with breathing
      15. dryness of the mouth or throat
      16. earache
      17. excess air or gas in the stomach or intestines
      18. excessive tearing
      19. eye discharge
      20. feeling faint, dizzy, or lightheadedness
      21. feeling of warmth or heat
      22. flushed, dry skin
      23. flushing or redness of the skin, especially on the face and neck
      24. frequent urination
      25. fruit-like breath odor
      26. impaired vision
      27. incoordination
      28. increased hunger
      29. increased sensitivity to pain
      30. increased sensitivity to touch
      31. increased thirst
      32. indigestion
      33. noise in the ears
      34. pain, redness, rash, swelling, or bleeding where the skin is rubbed off
      35. passing gas
      36. redness or swelling in the ear
      37. redness, pain, swelling of the eye, eyelid, or inner lining of the eyelid
      38. runny nose
      39. sneezing
      40. sweating
      41. tender, swollen glands in the neck
      42. tightness in the chest
      43. tingling in the hands and feet
      44. trouble sleeping
      45. trouble swallowing
      46. trouble thinking
      47. twitching
      48. unexplained weight loss
      49. voice changes
      50. vomiting
      51. weakness or loss of strength
      52. weight gain

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Gabapentin is a prescription and we do not suggest you take it for a long time. You need take some health food or USANA CellSentials™ to make yourself more strong. If you want to make yourself happy and more beautiful without any pain, please check Celavive Skin Care and Whitening Teeth