What is the less common side effects of Gabapentin ?

Less common or rare side effects of Gabapentin

Accidental injury
appetite increased
back pain
bloated or full feeling
body aches or pain
burning, dry, or itching eyes
change in vision
change in walking and balance
clumsiness or unsteadiness
congestion
constipation
cough producing mucus
decrease in sexual desire or ability
difficulty with breathing
dryness of the mouth or throat
earache
excess air or gas in the stomach or intestines
excessive tearing
eye discharge
feeling faint, dizzy, or lightheadedness
feeling of warmth or heat
flushed, dry skin
flushing or redness of the skin, especially on the face and neck
frequent urination
fruit-like breath odor
impaired vision
incoordination
increased hunger
increased sensitivity to pain
increased sensitivity to touch
increased thirst
indigestion
noise in the ears
pain, redness, rash, swelling, or bleeding where the skin is rubbed off
passing gas
redness or swelling in the ear
redness, pain, swelling of the eye, eyelid, or inner lining of the eyelid
runny nose
sneezing
sweating
tender, swollen glands in the neck
tightness in the chest
tingling in the hands and feet
trouble sleeping
trouble swallowing
trouble thinking
twitching
unexplained weight loss
voice changes
vomiting
weakness or loss of strength
weight gain

What is the Most Common Side Effect of Gabapentin?

Along with its needed effects, gabapentin 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 while taking gabapentin:

More common

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

More common in children

Aggressive behavior or other behavior problems
anxiety
concentration problems and change in school performance
crying
depression
false sense of well-being
hyperactivity or increase in body movements
rapidly changing moods
reacting too quickly, too emotional, or overreacting
restlessness
suspiciousness or distrust

Less common

Black, tarry stools
chest pain
chills
cough
depression, irritability, or other mood or mental changes
fever
loss of memory
pain or swelling in the arms or legs
painful or difficult urination
shortness of breath
sore throat
sores, ulcers, or white spots on the lips or in the mouth
swollen glands
unusual bleeding or bruising
unusual tiredness or weakness

Incidence not known

Abdominal or stomach pain
blistering, peeling, or loosening of the skin
clay-colored stools
coma
confusion
convulsions
dark urine
decreased urine output
diarrhea
dizziness
fast or irregular heartbeat
headache
increased thirst
itching or skin rash
joint pain
large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
loss of appetite
muscle ache or pain
nausea
red skin lesions, often with a purple center
red, irritated eyes
unpleasant breath odor
vomiting of blood
yellow eyes or skin

Some side effects of gabapentin 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

Blurred vision
cold or flu-like symptoms
delusions
dementia
hoarseness
lack or loss of strength
lower back or side pain
swelling of the hands, feet, or lower legs
trembling or shaking

Gabapentin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

drowsiness
tiredness or weakness
dizziness
headache
uncontrollable shaking of a part of your body
double or blurred vision
unsteadiness
anxiety
memory problems
strange or unusual thoughts
unwanted eye movements
nausea
vomiting
heartburn
diarrhea
dry mouth
constipation
increased appetite
weight gain
swelling of the hands, feet, ankles, or lower legs
back or joint pain
fever
runny nose, sneezing, cough, sore throat, or flu-like symptoms
ear pain
red, itchy eyes (sometimes with swelling or discharge)

Some side effects may be serious. If you experience any of the following symptoms, call your doctor immediately:

rash
itching
swelling of the face, throat, tongue, lips, or eyes
hoarseness
difficulty swallowing or breathing
seizures
difficulty breathing; bluish-tinged skin, lips, or fingernails; confusion; or extreme sleepiness

Gabapentin may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

How does Gabapentin Work ?

Gabapentin is a medicine that may be used for the treatment of certain seizure disorders or nerve pain.

Experts aren’t sure exactly how gabapentin works, but research has shown that gabapentin binds strongly to a specific site (called the alpha2-delta site) on voltage-gated calcium channels. This action is thought to be the mechanism for its nerve-pain relieving and anti-seizure properties.

Gabapentin enacarbil (brand name Horizant) is a prodrug of gabapentin which has been designed to overcome the limitations of gabapentin, such as poor absorption and a short duration of action. Gabapentin enacarbil is effective for restless legs syndrome (RLS) and postherpetic neuralgia (nerve pain that occurs following Shingles).

Gabapentin belongs to the group of medicines known as anticonvulsants.

Key facts

You’ll usually take gabapentin 3 times a day. You can take it with or without food.
Most people who take gabapentin do not get any side effects. But some people may feel sleepy, tired and dizzy. Common side effects are usually mild and go away by themselves.
It takes at least a few weeks for gabapentin to work.
Most people do not have to stay on the same brand of gabapentin as there’s very little difference between brands.
Some people can become addicted to gabapentin after taking it for a long time. When stopping gabapentin you’ll need to reduce your dose gradually to avoid withdrawal symptoms.
If you have epilepsy, you are entitled to free prescriptions for all the medicines you take, not just your epilepsy ones. You can get an application form from your doctor’s surgery.

Gabapentin, Impotence and Other Problems of Taking Gabapentin

I was just hoping that you might have the answer I am hoping for?

I started taking gabapentin 300mg twice a day, then 3 times a day, then 600mg twice a day then 3 times a day, now after 2 to 3 years later 800mg 3 times a day.

My doctor says it won’t cause erectile dysfunction but it started very soon after the 300mg 3 times a day. I tried Viagra and Cialis very little help. My wife is very displeased and sometimes thinks it is something to do with her. I know it has nothing to do with her as she is my bride of 24 years and my soul mate spirit. I have very bad pain that the gabapentin used to help with but it now seems it helps no more.

I would rather have my manhood back and my bride be happy and me than be in pain that just won’t go away. To get to the real question, how slowly should I get off the gabapentin and will I ever be able to get back to normal?

I will have to just have to tolerate the pain now that I have my diabetes under control. I rarely have to take my diabetes medicine but a few times a week because it makes my numbers to low and I black out when they get to low.

Usually 82 morning, 92 lunch, and 98 dinner. Any help will be greatly appreciated.

Answers:

Unfortunately gabapentin can cause impotence.

Side effects of the Urogenital System:

Infrequent: urinary tract infection, dysuria, impotence, urinary incontinence, vaginal moniliasis, breast pain, menstrual disorder, polyuria, urinary retention

Rare: cystitis, ejaculation abnormal, swollen penis, gynecomastia, nocturia, pyelonephritis, swollen scrotum, urinary frequency, urinary urgency, urine abnormality.

Talk to your doctor about coming off gabapentin and he/she could put you on some other medicine to help the pain. You don’t have to ween off gabapentin but please get your doctor to monitor you once you are off.

Cautions with other medicines

Some medicines may affect how gabapentin works or increase the chance of you having side effects.

Antacids can reduce the amount of gabapentin that the body takes in so it does not work as well. To stop this happening, if you need to take an antacid, take it at least 2 hours before or after your dose of gabapentin.

Tell your doctor if you’re taking any of these medicines before you start gabapentin treatment:

strong painkillers, such as morphine – these can make you very tired and dizzy when you start taking gabapentin
antidepressants, such as amitriptyline or fluoxetine
antipsychotic medicines for mental health problems like schizophrenia or bipolar disorder
a medicine to prevent malaria called mefloquine

Gabapentin Drug Interaction

Alcohol (Ethyl): CNS Depressants may enhance the CNS depressant effect of Alcohol (Ethyl). Monitor therapy

Alizapride: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Aluminum Hydroxide: May decrease the serum concentration of Gabapentin. Management: Administer gabapentin at least 2 hours after administration of antacids containing aluminum hydroxide or magnesium hydroxide. Consider therapy modification

Azelastine (Nasal): CNS Depressants may enhance the CNS depressant effect of Azelastine (Nasal). Avoid combination

Blonanserin: CNS Depressants may enhance the CNS depressant effect of Blonanserin. Consider therapy modification

Brexanolone: CNS Depressants may enhance the CNS depressant effect of Brexanolone. Monitor therapy

Brimonidine (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Bromopride: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Bromperidol: May enhance the CNS depressant effect of CNS Depressants. Avoid combination

Buprenorphine: CNS Depressants may enhance the CNS depressant effect of Buprenorphine. Management: Consider reduced doses of other CNS depressants, and avoiding such drugs in patients at high risk of buprenorphine overuse/self-injection. Initiate buprenorphine at lower doses in patients already receiving CNS depressants. Consider therapy modification

Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Cannabis: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Chlormethiazole: May enhance the CNS depressant effect of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used. Consider therapy modification

Chlorphenesin Carbamate: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy

CNS Depressants: May enhance the adverse/toxic effect of other CNS Depressants. Monitor therapy

Dimethindene (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Doxylamine: May enhance the CNS depressant effect of CNS Depressants. Management: The manufacturer of Diclegis (doxylamine/pyridoxine), intended for use in pregnancy, specifically states that use with other CNS depressants is not recommended. Monitor therapy

Dronabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Droperidol: May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (eg, opioids, barbiturates) with concomitant use. Exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Consider therapy modification

Esketamine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Flunitrazepam: CNS Depressants may enhance the CNS depressant effect of Flunitrazepam. Consider therapy modification

HYDROcodone: CNS Depressants may enhance the CNS depressant effect of HYDROcodone. Management: Avoid concomitant use of hydrocodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

HydrOXYzine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Kava Kava: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy

Lofexidine: May enhance the CNS depressant effect of CNS Depressants. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Monitor therapy

Magnesium Salts: May enhance the CNS depressant effect of Gabapentin. Specifically, high dose intravenous/epidural magnesium sulfate may enhance the CNS depressant effects of gabapentin. Magnesium Salts may decrease the serum concentration of Gabapentin. Management: Administer gabapentin at least 2 hours after use of a magnesium-containing antacid. Monitor patients closely for evidence of reduced response to gabapentin therapy. Monitor for CNS depression if high dose IV/epidural magnesium sulfate is used. Consider therapy modification

Mefloquine: May diminish the therapeutic effect of Anticonvulsants. Mefloquine may decrease the serum concentration of Anticonvulsants. Management: Mefloquine is contraindicated for malaria prophylaxis in persons with a history of convulsions. Monitor anticonvulsant concentrations and treatment response closely with concurrent use. Consider therapy modification

Methotrimeprazine: CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of CNS Depressants. Management: Reduce adult dose of CNS depressant agents by 50% with initiation of concomitant methotrimeprazine therapy. Further CNS depressant dosage adjustments should be initiated only after clinically effective methotrimeprazine dose is established. Consider therapy modification

MetyroSINE: CNS Depressants may enhance the sedative effect of MetyroSINE. Monitor therapy

Mianserin: May diminish the therapeutic effect of Anticonvulsants. Monitor therapy

Minocycline: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Minocycline (Systemic): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Morphine (Systemic): Gabapentin may enhance the CNS depressant effect of Morphine (Systemic). Morphine (Systemic) may increase the serum concentration of Gabapentin. Monitor therapy

Nabilone: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Opioid Agonists: CNS Depressants may enhance the CNS depressant effect of Opioid Agonists. Management: Avoid concomitant use of opioid agonists and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Orlistat: May decrease the serum concentration of Anticonvulsants. Monitor therapy

Orphenadrine: CNS Depressants may enhance the CNS depressant effect of Orphenadrine. Avoid combination

Oxomemazine: May enhance the CNS depressant effect of CNS Depressants. Avoid combination

OxyCODONE: CNS Depressants may enhance the CNS depressant effect of OxyCODONE. Management: Avoid concomitant use of oxycodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Paraldehyde: CNS Depressants may enhance the CNS depressant effect of Paraldehyde. Avoid combination

Perampanel: May enhance the CNS depressant effect of CNS Depressants. Management: Patients taking perampanel with any other drug that has CNS depressant activities should avoid complex and high-risk activities, particularly those such as driving that require alertness and coordination, until they have experience using the combination. Consider therapy modification

Piribedil: CNS Depressants may enhance the CNS depressant effect of Piribedil. Monitor therapy

Pramipexole: CNS Depressants may enhance the sedative effect of Pramipexole. Monitor therapy

ROPINIRole: CNS Depressants may enhance the sedative effect of ROPINIRole. Monitor therapy

Rotigotine: CNS Depressants may enhance the sedative effect of Rotigotine. Monitor therapy

Rufinamide: May enhance the adverse/toxic effect of CNS Depressants. Specifically, sleepiness and dizziness may be enhanced. Monitor therapy

Selective Serotonin Reuptake Inhibitors: CNS Depressants may enhance the adverse/toxic effect of Selective Serotonin Reuptake Inhibitors. Specifically, the risk of psychomotor impairment may be enhanced. Monitor therapy

Sodium Oxybate: May enhance the CNS depressant effect of CNS Depressants. Management: Consider alternatives to combined use. When combined use is needed, consider minimizing doses of one or more drugs. Use of sodium oxybate with alcohol or sedative hypnotics is contraindicated. Consider therapy modification

Suvorexant: CNS Depressants may enhance the CNS depressant effect of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Consider therapy modification

Tapentadol: May enhance the CNS depressant effect of CNS Depressants. Management: Avoid concomitant use of tapentadol and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Tetrahydrocannabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Tetrahydrocannabinol and Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Thalidomide: CNS Depressants may enhance the CNS depressant effect of Thalidomide. Avoid combination

Trimeprazine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Zolpidem: CNS Depressants may enhance the CNS depressant effect of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Consider therapy modification

Gabapentin is Used for Restless legs syndrome

Gabapentin in the management of restless legs syndrome (RLS) has been evaluated in small controlled trials, demonstrating benefits compared with placebo.

Gabapentin is sometimes used off-label for the treatment of restless legs syndrome (RLS), which is a neurological disorder characterized by an irresistible urge to move the legs, often accompanied by unpleasant sensations such as tingling or crawling.

While the exact mechanism of action of gabapentin in RLS is not well understood, it is believed that gabapentin may help alleviate RLS symptoms by modulating the levels of certain neurotransmitters in the brain, including gamma-aminobutyric acid (GABA) and glutamate.

However, it is important to note that the effectiveness of gabapentin for the treatment of RLS is still under investigation, and more research is needed to determine the optimal dosage, treatment duration, and potential side effects. Patients with RLS should always consult their healthcare provider before starting or changing any medication regimen.

Restless legs syndrome (RLS) is a condition that causes an uncontrollable urge to move the legs, usually because of an uncomfortable sensation. It typically happens in the evening or nighttime hours when you’re sitting or lying down. Moving eases the unpleasant feeling temporarily.

Restless legs syndrome, also known as Willis-Ekbom disease, can begin at any age and generally worsens as you age. It can disrupt sleep, which interferes with daily activities.

Simple self-care steps and lifestyle changes may help relieve symptoms. Medications also help many people with RLS.

Gabapentin enacarbil is FDA-approved for the treatment of RLS .

The American Academy of Sleep Medicine (AASM) guidelines regarding RLS management consider gabapentin effective based on low-level evidence and note that patients with pain symptoms appeared to benefit most.

The benefit-risk ratio is unclear. The European Federation of Neurological Societies/European Neurological Society/European Sleep Research Society (EFNS/ENS/ESRS) Task Force guidelines consider gabapentin effective for short-term management and possibly effective for long-term management of RLS.

Additional study is needed to establish optimal dosing. Based on the International Restless Legs Syndrome Study Group, European Restless Legs Syndrome Study Group, and RLS Foundation (IRLSSG/EURLSSG/RLS-F) guidelines for the prevention and treatment of dopaminergic augmentation in restless legs syndrome, α2δ ligands (eg, gabapentin) are effective and should be considered for the initial treatment of patients with RLS due to their minimal risk of augmentation.

Additionally, patients who experience augmentation on dopaminergic agents may benefit from a switch to α2δ ligands (eg, gabapentin). However, the guidelines note that long-term studies are needed.

There are several non-pharmacological approaches that may help alleviate the symptoms of restless legs syndrome (RLS), including:

Regular exercise: Engaging in moderate exercise, such as walking or yoga, on a regular basis may help reduce symptoms of RLS.
Hot or cold compresses: Applying a hot or cold compress to the legs may help alleviate discomfort and reduce the urge to move the legs.
Massage: Gentle massage or self-massage of the legs may help relax muscles and improve circulation.
Compression stockings: Wearing compression stockings or socks may help improve blood flow and reduce symptoms of RLS.
Relaxation techniques: Practicing relaxation techniques, such as deep breathing, meditation, or progressive muscle relaxation, may help reduce stress and tension in the body, which can exacerbate symptoms of RLS.
Maintaining a regular sleep schedule: Establishing a regular sleep schedule, including a consistent bedtime and wake-up time, may help improve sleep quality and reduce symptoms of RLS.
Avoiding triggers: Avoiding triggers such as caffeine, alcohol, and nicotine, as well as certain medications, may help reduce symptoms of RLS.

It is important to note that these approaches may not work for everyone with RLS, and individuals should talk to their healthcare provider before starting any new treatment regimen.

Gabapentin is Used for Neuropathic Pain (Other Than Postherpetic Neuralgia)

In a meta-analysis of trials evaluating the treatment of neuropathic pain, including painful polyneuropathy and spinal cord injury pain, gabapentin was shown to be safe and effective . Data from meta-analyses support the use of immediate-release gabapentin for reducing pain by more than 50% in diabetic neuropathy.\

Gabapentin is commonly prescribed off-label for various conditions, including anxiety, insomnia, bipolar disorder, alcohol withdrawal, and neuropathic pain associated with cancer, HIV, or other medical conditions. However, it is important to note that the off-label use of gabapentin is not approved by the FDA and may carry some risks.

Some manufacturers of gabapentin include Pfizer, which markets the drug under the brand name Neurontin, and various generic manufacturers who produce gabapentin under different brand names or as a generic medication. Some of the brand names for gabapentin include Gralise, Gabarone, and Horizant.

What is neuropathic pain?

Neuropathic pain can happen if your nervous system is damaged or not working correctly. You can feel pain from any of the various levels of the nervous system—the peripheral nerves, the spinal cord and the brain. Together, the spinal cord and the brain are known as the central nervous system. Peripheral nerves are the ones that are spread throughout the rest of your body to places likes organs, arms, legs, fingers and toes.

Damaged nerve fibers send the wrong signals to pain centers. Nerve function may change at the site of the nerve damage, as well as areas in the central nervous system (central sensitization).

Neuropathy is a disturbance of function or a change in one or several nerves. Diabetes is responsible for about 30% of neuropathy cases. It is not always easy to tell the source of the neuropathic pain. There are hundreds of diseases that are linked to this kind of pain.

Data from a limited number of clinical trials support the use of extended-release gabapentin in reducing pain by more than 50% and improving sleep in diabetic neuropathy.

Based on guidelines from the International Association for the Study of Pain (IASP), European Federation of Neurological Societies (EFNS), and Society of Critical Care Medicine (SCCM), gabapentin is effective and recommended for the management of peripheral neuropathy .

Based on guidelines from the EFNS, IASP, and National Institute for Health and Care Excellence (NICE), gabapentin is effective and recommended as first-line therapy, supported by strong evidence, in the management of diabetic neuropathy.

The IASP guidelines recommend both immediate- and extended-release gabapentin . In contrast, a guideline from the American Academy of Neurology (AAN), American Association of Neuromuscular and Electrodiagnostic Medicine, and American Academy of Physical Medicine and Rehabilitation states that gabapentin is probably effective and should be considered an alternative treatment for painful diabetic neuropathy based on limited benefit in 2 controlled trials.

Similarly, a position statement from the American Diabetes Association (ADA) recommends gabapentin as a second-line option .

Gabapentin Usage for Alcohol Disorder and Alcohol Withdrawal

Alcohol use disorder, moderate to severe (alternative agent)

Data from randomized, double-blind, placebo-controlled studies support the use of gabapentin in the maintenance of abstinence in patients with alcohol use disorder.

Based on the American Psychiatric Association (APA) guidelines for the pharmacological treatment of patients with alcohol use disorder, gabapentin is suggested for patients with alcohol use disorder (moderate to severe) who want to decrease or abstain from use of alcohol and either prefer gabapentin or are unable to tolerate or are unresponsive to naltrexone and acamprosate .

Based on the VA/DoD clinical practice guideline for the management of substance use disorders, gabapentin given for moderate to severe alcohol use disorder is effective and suggested when first-line pharmacotherapy is contraindicated or ineffective.

Alcohol withdrawal, mild (alternative agent)

Data from a randomized, double-blind, active-controlled study support the use of gabapentin in the treatment of alcohol withdrawal.

Based on the VA/DoD clinical practice guideline for the management of substance use disorders, gabapentin given for mild alcohol withdrawal is effective and suggested when the risk of benzodiazepines outweigh the benefits (eg, inadequate monitoring available, abuse liability, contraindication, adverse reaction).

Gabapentin Pharmacology

Gabapentin is structurally related to GABA. However, it does not bind to GABA_A or GABA_B receptors, and it does not appear to influence synthesis or uptake of GABA.

Gabapentin is a medication that belongs to the class of drugs known as anticonvulsants or antiepileptics. It is primarily used to treat seizures and neuropathic pain, but it is also used off-label for various other conditions such as anxiety, insomnia, and restless leg syndrome.

Gabapentin works by binding to a specific type of voltage-gated calcium channel (the alpha-2-delta subunit) in the brain and spinal cord. This reduces the release of various neurotransmitters, including glutamate, substance P, and noradrenaline, which are involved in pain perception and seizures.

Gabapentin is rapidly absorbed after oral administration, and its bioavailability is not affected by food. The peak plasma concentration is reached within 2-3 hours after administration. Gabapentin is not metabolized in the liver and is primarily eliminated by renal excretion.

The half-life of gabapentin is approximately 5-7 hours, and it is typically administered three times a day to maintain therapeutic levels in the blood. The dosage of gabapentin may need to be adjusted in patients with renal impairment, and it should be used with caution in patients with a history of substance abuse or suicidal ideation.

Overall, gabapentin is a well-tolerated medication, but common side effects may include dizziness, drowsiness, fatigue, and ataxia. Gabapentin may also increase the risk of suicidal thoughts or behaviors, particularly in younger patients. Therefore, close monitoring is recommended during treatment with gabapentin.

High affinity gabapentin binding sites have been located throughout the brain; these sites correspond to the presence of voltage-gated calcium channels specifically possessing the alpha-2-delta-1 subunit.

This channel appears to be located presynaptically, and may modulate the release of excitatory neurotransmitters which participate in epileptogenesis and nociception.

Absorption

Variable, from proximal small bowel by L-amino transport system; saturable process; dose-dependent

V_d: 58 ± 6 L; CSF concentrations are ~20% of plasma concentrations

Metabolism

Not metabolized

Excretion

Proportional to renal function; urine (as unchanged drug)

Clearance: Apparent oral clearance is directly proportional to CrCl: Clearance in infants is highly variable; oral clearance (per kg) in children <5 years of age is higher than in children ≥5 years of age

Time to Peak

Immediate release: Infants 1 month to Children 12 years: 2 to 3 hours; Adults: 2 to 4 hours; Extended release: 8 hours

Half-Life Elimination

Infants 1 month to Children 12 years: 4.7 hours

Adults, normal: 5 to 7 hours; increased half-life with decreased renal function; anuric adult patients: 132 hours; adults during hemodialysis: 3.8 hours

Protein Binding

<3%

Gabapentin Side Effects

Applies to gabapentin: oral capsule, oral solution, oral suspension, oral tablet

Along with its needed effects, gabapentin 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 while taking gabapentin:

More common

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

More common in children

Aggressive behavior or other behavior problems
anxiety
concentration problems and change in school performance
crying
depression
false sense of well-being
hyperactivity or increase in body movements
rapidly changing moods
reacting too quickly, too emotional, or overreacting
restlessness
suspiciousness or distrust

Less common

Black, tarry stools
chest pain
chills
cough
depression, irritability, or other mood or mental changes
fever
loss of memory
pain or swelling in the arms or legs
painful or difficult urination
shortness of breath
sore throat
sores, ulcers, or white spots on the lips or in the mouth
swollen glands
unusual bleeding or bruising
unusual tiredness or weakness

Incidence not known

Abdominal or stomach pain
blistering, peeling, or loosening of the skin
clay-colored stools
coma
confusion
convulsions
dark urine
decreased urine output
diarrhea
dizziness
fast or irregular heartbeat
headache
increased thirst
itching or skin rash
joint pain
large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
loss of appetite
muscle ache or pain
nausea
red skin lesions, often with a purple center
red, irritated eyes
unpleasant breath odor
vomiting of blood
yellow eyes or skin

More common

Blurred vision
cold or flu-like symptoms
delusions
dementia
hoarseness
lack or loss of strength
lower back or side pain
swelling of the hands, feet, or lower legs
trembling or shaking

Less common or rare

Accidental injury
appetite increased
back pain
bloated or full feeling
body aches or pain
burning, dry, or itching eyes
change in vision
change in walking and balance
clumsiness or unsteadiness
congestion
constipation
cough producing mucus
decrease in sexual desire or ability
difficulty with breathing
dryness of the mouth or throat
earache
excess air or gas in the stomach or intestines
excessive tearing
eye discharge
feeling faint, dizzy, or lightheadedness
feeling of warmth or heat
flushed, dry skin
flushing or redness of the skin, especially on the face and neck
frequent urination
fruit-like breath odor
impaired vision
incoordination
increased hunger
increased sensitivity to pain
increased sensitivity to touch
increased thirst
indigestion
noise in the ears
pain, redness, rash, swelling, or bleeding where the skin is rubbed off
passing gas
redness or swelling in the ear
redness, pain, swelling of the eye, eyelid, or inner lining of the eyelid
runny nose
sneezing
sweating
tender, swollen glands in the neck
tightness in the chest
tingling in the hands and feet
trouble sleeping
trouble swallowing
trouble thinking
twitching
unexplained weight loss
voice changes
vomiting
weakness or loss of strength
weight gain

You can not take Prescription for a long time, you need find a way to treat your pain without prescription. Exercising is the best way to relieve your pain. because exercising can enhance your immune system and increase your muscle strength and make your nerve strong.