Gabapentin

1 What is gabapentin?

Brand: Neurontin, Horizant, Fanatrex, Gabarone

Generic: Gabapentin

Gabapentin is an antiepileptic drug (AED). It is also sometimes called anticonvulsant medication.

It is available in 100-, 300-, and 400-mg capsules, 800-mg tablets, as well as in suspension form. Formulation of gabapentin for rapid titration is also available.

Gabapentin is a prescription-only medicine. Therefore, it cannot be purchased over the counter from your local pharmacy. Make sure to seek professional medical advice before taking gabapentin for treatment to certify that this is the medication you need for your condition.

Popular brand names for gabapentin are Neurontin, Horizant, Fanatrex, and Gabarone.

Gabapentin does not metabolize in the kidney or liver, which makes it ideal for patients with renal or hepatic disease as well as patients with complex medication routines.

2 Gabapentin side effects

Like with most medicine, taking gabapentin produces needed effects that help patients continue with their day-to-day activities with minimal interruption or discomfort. But along with intended effects comes unwanted side effects, that are in general, minor when compared to the good effects of the medication.

Here are side effects that have been noted upon taking gabapentin:

  • Blurred vision or another change in vision
  • Burning, dry, or itchy eyes; excessive tearing or eye discharge
  • Feeling faint, dizzy, or lightheadedness
  • Lack or loss of strength
  • Earache or noise in the ears
  • Clumsiness or unsteadiness, or change in walking and balance
  • Accidental injury
  • Cold or flu-like symptoms, or mucus-producing cough
  • Delusions, confusion, or trouble thinking
  • Hoarseness and other voice changes
  • Trembling, shaking or twitching
  • Increased hunger and appetite, weight gain, or unexplained weight loss
  • Constipation, gas, bloated or full feeling, indigestion, or vomiting
  • Decrease in sexual desire or ability
  • Difficulty breathing, tightness in the chest
  • Dryness of the mouth or throat, trouble swallowing, fruit-like breath odor, or increased thirst
  • Feeling of warmth or heat; flushed, dry skin
  • Increased sensitivity to touch and pain
  • Lower back or side pain, and other body aches
  • Pain, redness, rash, swelling of the skin
  • Redness or swelling in the ear
  • Redness, pain, swelling of the eye, eyelid, or inner lining of the eyelid
  • Flushing or redness of the skin, especially on the face and neck
  • Tender, swollen glands in the neck
  • Tingling in the hands and feet
  • Swelling of the hands, feet, or lower legs
  • Trouble sleeping
  • Frequent urination

These are minor side effects that the patient can usually ignore. But there are also major side effects that require immediate medical attention. If you experience any of the side effects listed below, contact your doctor at once.

  • Extreme clumsiness or unsteadiness
  • Continuous, uncontrolled, back-and-forth, or rolling eye movements
  • Black, tarry or clay-colored stools
  • Diarrhea, abdominal or stomach pain
  • Vomiting of blood
  • Fever, chills, or convulsions
  • Depression, irritability, or other mood or mental changes
  • Loss of memory
  • Coma, dizziness, headache, nausea
  • Increased or irregular heartbeat
  • Chest pain
  • Unusual tiredness or weakness
  • Shortness of breath
  • Sore throat
  • Increased thirst
  • Unpleasant breath odor
  • Loss of appetite
  • Pain or swelling in the arms or legs
  • Painful or difficult urination, decreased urine output, dark urine
  • Sores, ulcers, or white spots on the lips or in the mouth
  • Swollen glands, joint pains
  • Unusual bleeding or bruising
  • Yellow eyes or skin
  • Red, irritated eyes
  • Blistering, peeling, or loosening of the skin
  • Itching or skin rash
  • Large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • Red skin lesions, often with a purple center

These major side effects are specific to children:

  • Aggressive behavior or other behavioral problems
  • Anxiety
  • Crying, depression, and suspiciousness or distrust
  • Concentration problems and change in school performance
  • False sense of well-being
  • Hyperactivity or increase in body movements, or restlessness
  • Rapidly changing moods; or reacting too quickly, too emotionally, or overreacting
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3 Gabapentin dosage

Gabapentin is a prescription medication. This means that a patient is required to see his or her doctor in order to get a prescription. Self-medication is not an option, whether you are taking gabapentin for nerve pain or for epileptic seizures.

This medication may be taken with or without food. Upon breaking a scored tablet, use within 28 days. Otherwise, the medicine should be discarded.

Here are the common dosages prescribed for each specific condition.

  • Dosage of gabapentin for adults, to treat epileptic seizures
    • Initial dose: Day 1, 300-mg orally once; Day 2, 300-mg taken orally two times a day; Day 3, 300-mg taken orally three times a day.
    • Maintenance dose: 3600-mg orally, divided into three doses, not exceeding 12 hours in between each dose.
  • Dosage of gabapentin for adults, to treat postherpetic neuralgia
    • Initial dose: Day 1, 300-mg orally once; Day 2, 300-mg taken orally two times a day; Day 3, 300-mg taken orally three times a day.
    • Maintenance dose: Dosage is increased as needed for pain relief. The maximum dosage is 1800-mg per day, or 600-mg taken orally three times a day.
    • For this condition, the doctor may prescribe an extended-release tablet. This is available under the brand Horizant.
  • Dosage of gabapentin for adults, to treat restless leg syndrome (RLS)
    • Dosage: 600-mg taken orally once a day, with food, in the evening.
  • Dosage of gabapentin for children aged 3 to 11 years
    • Initial dose: 10- to 15-mg/kg/day, divided into three doses.
    • Maintenance dose: titrate up over three days until effective dosage is reached; for children aged five and up, 25- to 35-mg/kg/day, divided into three doses; for children aged three and four, 40-mg/kg/day, divided into three doses.
    • Dosages of up to 50-mg/kg/day have been well-tolerated in a long-term clinical study.
    • The maximum time between each dose should be 12 hours.
  • Dosage of gabapentin for children aged 12 and up
    • Initial dose: Day 1, 300-mg orally once; Day 2, 300-mg taken orally twice a day; Day 3, 300-mg taken orally three times a day.
    • Maintenance dose: 900- to 1800-mg taken orally, divided into three doses.
    • Dosages of up to 3600-mg/day given to a small number of patients has been well-tolerated for a short duration.
    • The maximum time between each dose should not exceed 12 hours.

4 Gabapentin safety

Reading about dosage cannot replace the professional advice of a physician. Your doctor will prescribe what is the right medication and the right dosage for your specific condition. This is even more important if you have other conditions to factor in. These conditions include renal and hepatic diseases.

Do not be afraid to ask your doctor and/or pharmacist a lot of questions. It is important that you fully understand what your prescription says in order for you to follow the treatment plan properly.

In case you miss a dose, take it as soon as you remember the missed dose. But, if it is too close to the next one, it is better to wait it out and continue taking your medication as scheduled. Do not take two doses at once. This may cause over dosage, which is toxic to the body. If you suspect over dosage, watch out for symptoms like nausea, vomiting, dizziness, difficulty breathing, and extreme tiredness. Seek emergency medical attention or contact your local poison center.

Do not suddenly stop taking gabapentin. If you are taking the medication to prevent seizures, this may cause an increased risk for occurrence of seizures. If, for any reason, you need to end the treatment, inform your doctor so that he can guide you on how to do this properly and safely.

Gabapentin dosages may also need to be adjusted if you are pregnant, trying to become pregnant, or planning on breastfeeding. Inform your doctor of these conditions to ensure that no harm will come to your child.

For pregnancies, the doctor will weigh the need for antiepileptic drugs against the safety of your pregnancy. The doctor will only recommend medication if risks are minimal and will be outweighed by the benefits the mother will receive in taking antiepileptic drugs.

On the other hand, gabapentin has been shown to be excreted into human milk and transferred to the child while breastfeeding. Although studies have shown that the child remains healthy and well despite this, make sure that you have a doctor to monitor your and your child’s progress. The baby will be checked according to the following criteria: drowsiness, developmental milestones, and adequate weight gain.

5 What is gabapentin used for?

There are various processes and structures involved in the manifestation of a seizure. Examples of the structures involved are neurons, receptors, ion channels, glia, and excitatory and inhibitory synapses. Antiepileptic drugs (AEDs), like gabapentin, act on the chemicals, nerves, and other elements of the body to modify their processes to favor inhibition over excitation, thereby preventing seizure activities.

 

Gabapentin is not effective on all types of seizures. It is more commonly prescribed for focal or partial seizures, and the same partial seizures with secondary generalization. It is also important to note that while gabapentin is effective in preventing partial seizures associated with epilepsy, this medication is not used to treat epilepsy itself, only the seizures caused by it.

 

Aside from interfering with seizure activity, gabapentin also treats various types of pain. Gabapentin is used to treat neuropathic pain in adults, where the pain is caused by shingles (herpes zoster) or herpes virus. It is also useful in treating diabetic peripheral neuropathy. Gabapentin is used to relieve pain for specific conditions in the nervous system. It should not be used for arthritis, muscle pain, and minor injuries.

Some doctors also prescribe gabapentin for anxiety and bipolar disorder.

Here is a list of other conditions treated with gabapentin:

Some gabapentin brands are used for other purposes. The brand Horizant is used to treat restless legs syndrome (RLS), while the brand Neurontin is used to treat seizures in children aged three and up. Because of the variations from brand to brand, it is important that the patient take the medication and brand specifically stated in his or her prescription. Double check the medicine you receive each time you refill a prescription from the pharmacy to be sure.

Gabapentin

6 How long does gabapentin stay in your system?

Steady-state levels are reached within just a few days. The drug stays in the system for five to nine hours. This remains unchanged with chronic administration of gabapentin. It is also not affected by concomitant medications.

7 Gabapentin withdrawal

When a patient suddenly stops taking gabapentin withdrawal symptoms may arise. Doctors and medical practitioners warn against the sudden stop of gabapentin treatment. This increases the risk of seizures if the medication is taken by an epileptic patient.

It also results to withdrawal symptoms like nausea, difficulty falling or staying asleep, excessive sweating, and pain.

However, not all patients experience gabapentin withdrawal symptoms. This is largely dependent on various factors, including the duration for which the medication was taken, in what dosage, the patient’s physiology, and how the treatment was stopped. In general, people who have been on the drug for longer and at higher dosages are more likely to experience withdrawal symptoms. When getting off of medication, your doctor will start prescribing smaller and smaller dosages of gabapentin to help ease your way out of the treatment. This is a good method of avoiding, or at least minimizing, withdrawal symptoms.

8 Gabapentin abuse

As long as the patient takes the medication as prescribed by the doctor (in the right dosage and time), and he or she regularly attends therapy or check-up sessions, there would be no cause to worry about possible addiction to the drug.

The effects of gabapentin vary largely depending on the user, dosage, past experience, psychiatric history and expectations. Some users have started using gabapentin recreationally and report experiences of euphoria, improved sociability, relaxation, a sense of calmness, and a high similar to that of marijuana’s.

Along with these effects desired by recreational users, gabapentin still comes along with unwanted side effects. If one takes gabapentin weight gain is a definite possibility. That is just one of its many side effects. Another important question a recreational user should consider is, “Does gabapentin make you tired?” Exhaustion, lethargy and weariness are all side effects associated with the use of gabapentin. People who take gabapentin unnecessarily will have to go through these side effects when there is not an actual need for it. Gabapentin abuse has also been shown to cause seizures in some users. This is very dangerous, especially for someone using it recreationally and who has never experienced a seizure before. The most dangerous possibility linked with recreational use is, of course, over dosage, which could ultimately lead to one’s death.

Despite being a prescription drug, gabapentin could be sold in online pharmacies, which is more lenient in following regulations. Some individuals could also go doctor shopping, going to several physicians in the pretext of looking for a doctor they can trust, when really they are just collecting prescriptions.

Spotting gabapentin abuse is crucial. Watch out for the following signs of abusers:

  • You will first notice in an abrupt change in their behavior, sleeping and eating habits, as well as personal hygiene routines and self-care interests.
  • They develop a secretive nature because they hide the fact that they are using drugs recreationally.
  • They may also change the group of friends they hang out with or if they used to prefer solitary time, they will now spend a lot of time with these new friends. These people would be the influencers for the user to take drugs recreationally. 

9 Lyrica vs. Gabapentin

Lyrica, or its generic name pregabalin, is also an antiepileptic drug, much like gabapentin. They are very similar in function. Pregabalin even falls under the same subcategory as gabapentin. They both imitate the GABA structure. Pregabalin also has analgesic and anxiolytic effects to help reduce pain and anxiety respectively.

Pregabalin or Lyrica is a newer AED, compared to gabapentin, and belongs to a higher price range. However, Lyrica has shown to produce lesser intolerable side effects at its initial dose. Doctors would often have to prescribe gabapentin at very low dosages and then titrate up gradually to reach the effective dosage. Gabapentin could cause extreme drowsiness, disequilibrium and confusion. But for Lyrica, doctors can prescribe at the effective dosage immediately without worry of intolerable side effects. This way, the patient feels therapeutic relief faster. This is important for conditions that cause acute pain, like shingles and trigeminal neuralgia.

Lyrica is also the first drug to be approved by the Food and Drug Administration (FDA) to treat fibromyalgia.

But as previously mentioned, these two drugs are very similar in nature. And because people vary greatly, some may experience more or less side effects from a specific drug than the next patient. In the end, it is a doctor’s professional opinion and advice that will guide patients as to which medication will work best for their specific condition.

10 Gabapentin drug class

Gabapentin belongs to the antiepileptic class of drugs. This classification is also called anticonvulsant. Antiepileptic drugs (AED) have been in use since 1940. But it was only in the 1990s that a newer generation of AEDs were developed. These AEDs, which included gabapentin, have shown to have good efficacy, better tolerability, and less toxic effects. Also, prior to 1990s, AED treatments went hand in hand with close blood level monitoring to ensure that while harnessing the positive effects of the medication, it is not causing harm to the patient’s body.

Other AEDs are acetazolamide, carbamazepine, clobazam, clonazepam, eslicarbazepine acetate, ethosuximide, lacosamide, lamotrigine, levetiracetam, nitrazepam, oxcarbazepine, perampanel, piracetam, phenobarbital, phenytoin, pregabalin, primidone, retigabine, rufinamide, sodium valproate, stiripentol, tiagabine, topiramate, vigabatrin and zonisamide.

AEDs can be further classified according to their main mechanism of action. They are classified according to their main mechanism of action because some AEDs have several actions, and for some of them, the mechanism of action is unknown.

The main sub-categories are sodium channel blockers, gamma-aminobutyric acid (GABA) enhancers, calcium current inhibitors, glutamate blockers, carbonic anhydrase inhibitors, hormones, and the last sub-category is for AEDs with unknown mechanisms of action.

Gabapentin is sub-classified with other AEDs with potential GABA mechanism of action, although the exact mechanism is unknown. GABA is one type of the inhibitory neurotransmitters in the brain. These effectively stop the brain from sending messages out. GABA aids chloride ions to pass into neurons, thereby affecting its resting membrane potential and making it difficult for neurons to send messages. Gabapentin help prevent epileptic seizures by increasing the production of GABA.

Other AEDs, on the other hand, work by decreasing the breakdown of GABA. Ultimately, the goal of drugs in this sub-category is to increase the amount of GABA present in the brain.

Gabapentin was designed to imitate the structure of GABA. However, experimental evidence shows that the medication has had little to no action on the GABA receptor. This does not to say though that gabapentin is not effective. It does increase the intracellular concentration of GABA, but not the exact mechanism by which gabapentin achieves that result is unknown. What is certain in gabapentin is that it binds with the alpha2 delta subunit of calcium channels in the hippocampus, neocortex, and spinal cord. This is essential to its efficacy in relieving pain.

One of the popular and infamous questions for gabapentin is, “Is gabapentin a narcotic?” The answer is, no, it is not. Nevertheless, this is an important question in understanding what medications exactly you are taking. However, a growing population has started using gabapentin recreationally. They claim to experience a gabapentin high while on this medication. Whether or not it is addictive, however, has yet to be proven. On the other hand, although not its primary use, gabapentin has been prescribed to treat addiction to cocaine, methadone and other narcotics, as well as addition to alcohol.

While gabapentin is believed to not cause addiction, taking it for chronic conditions like epilepsy does cause the patient to develop a physical dependence on the drug. This is why it is important to keep routine consultations with your physician as he is better able to assess your need for the drug and the improvement of your condition.

11 Gabapentin drug interactions

Gabapentin has no known pharmacokinetic drug interactions. This makes gabapentin ideal for patients who have complex medication routines. It is one drug less to worry about.

While gabapentin has very little interaction with other drugs, there are still some combinations you should be mindful of.

Gabapentin causes drowsiness so you should avoid taking other medications that slow down the central nervous system. Examples of such medicine are antihistamines, sleeping pills, muscle relaxants, narcotic painkillers, anti-anxiety medications, antidepressants and other antiepileptic drugs.

Here are some other drugs you should watch out for:

  • Ketorolac
  • Aluminum carbonate
  • Aluminum hydroxide
  • Aluminum phosphate
  • Dihydroxyaluminum amino acetate
  • Dihydroxyaluminum sodium carbonate
  • Ginkgo
  • Magaldrate
  • Magnesium carbonate
  • Magnesium hydroxide
  • Magnesium trislicate
  • Morphine sulfate liposome

Antacids also reduce the availability of gabapentin in the body as much as 20%. Do not take antacids with magnesium and aluminum hydroxides when you are also taking gabapentin. In such cases, gabapentin should be taken two hours after such antacid is ingested. It is always best to discuss your concerns with your physician.

In general, a patient should always take note of all of his medications, including prescription and over-the-counter drugs, nutritional supplements, and herbal medicines. Discuss this with your doctor to be on the safe side.

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