Gabapentin 400 mg is used with other medications to prevent and control seizures. It is also used to relieve nerve pain following shingles (a painful rash due to herpes zoster infection) in adults. Gabapentin 400 mg is known as an anticonvulsant or antiepileptic drug.
Gabapentin 400 mg comes as white, yellow or orange tablets / capsules. They are normally swallowed, although powder from capsules may be snorted.
- Gabapentin is indicated as adjunctive therapy in the treatment of partial seizures with and without secondary generalization in adults and children aged 6 years and above (see section 5.1).
- Gabapentin 400 mg or (Gabatop) is indicated as monotherapy in the treatment of partial seizures with and without secondary generalization in adults and adolescents aged 12 years and above.
Treatment of peripheral neuropathic pain
- Gabapentin is indicated for the treatment of peripheral neuropathic pain such as painful diabetic neuropathy and post-herpetic neuralgia in adults.
Uses Of Gabapentin 400 mg
- Read the Medication Guide and, if available, the Patient Information Leaflet provided by your pharmacist before you start taking gabapentin 400 mg and each time you get a refill. If you have any questions, ask your doctor or pharmacist.
- Take this medication by mouth with or without food as directed by your doctor. Dosage is based on your medical condition and response to treatment. For children, the dosage is also based on weight.
- If you are taking the tablets and your doctor directs you to split the tablet in half, take the other half-tablet at your next scheduled dose. Discard half tablets if not used within several days of splitting them. If you are taking the capsules, swallow them whole with plenty of water.
- It is very important to follow your doctor’s dosing instructions exactly. During the first few days of treatment, your doctor may gradually increase your dose so your body can adjust to the medication. To minimize side effects, take the very first dose at bedtime.
- Take this medication regularly to get the most benefit from it. This drug works best when the amount of medicine in your body is kept at a constant level. Therefore, take gabapentin 400 mg at evenly spaced intervals at the same time(s) each day. If you are taking this medication 3 times a day to control seizures, do not let more than 12 hours pass between doses because your seizures may increase.
- Do not take this medication more often or increase your dose without consulting your doctor. Your condition will not improve any faster and the risk of serious side effects may increase.
- Do not stop taking this medication without consulting your doctor. Some conditions may become worse when the drug is suddenly stopped. Your dose may need to be gradually decreased.
- Antacids containing aluminum or magnesium may interfere with the absorption of this medication. Therefore, if you are also taking an antacid, it is best to take gabapentin at least 2 hours after taking the antacid.
- Different forms of gabapentin (such as immediate-release, sustained-release, enacarbil sustained-release) are absorbed in the body differently. Do not switch from one form to the other without consulting your doctor.
- Tell your doctor if your condition does not improve or if it worsens.
Posology And Method OF Administration
For all indications a titration scheme for the initiation of therapy is described in Table 1, which is recommended for adults and adolescents aged 12 years and above. Dosing instructions for children under 12 years of age are provided under a separate sub-heading later in this section.
|DOSING CHART – INITIAL TITRATION|
|Day 1||Day 2||Day 3|
|300 mg once a day||300 mg two times a day||300 mg three times a day|
Discontinuation of Gabapentin 400 mg
In accordance with current clinical practice, if gabapentin has to be discontinued it is recommended this should be done gradually over a minimum of 1 week independent of the indication.
Epilepsy typically requires long-term therapy. Dosage is determined by the treating physician according to individual tolerance and efficacy.
Adults and Adolescents:
In clinical trials, the effective dosing range was 900 to 3600 mg/day. Therapy may be initiated by titrating the dose as described in Table 1 or by administering 300 mg three times a day (TID) on Day 1. Thereafter, based on individual patient response and tolerability, the dose can be further increased in 300 mg/day increments every 2-3 days up to a maximum dose of 3600 mg/day. Slower titration of gabapentin dosage may be appropriate for individual patients. The minimum time to reach a dose of 1800 mg/day is one week, to reach 2400 mg/day is a total of 2 weeks, and to reach 3600 mg/day is a total of 3 weeks.
Dosages up to 4800 mg/day have been well tolerated in long-term open-label clinical studies. The total daily dose should be divided in three single doses, the maximum time interval between the doses should not exceed 12 hours to prevent breakthrough convulsions.
Children aged 6 years and above:
The starting dose should range from 10 to 15 mg/kg/day and the effective dose is reached by upward titration over a period of approximately three days. The effective dose of gabapentin in children aged 6 years and older is 25 to 35 mg/kg/day. Dosages up to 50 mg/kg/day have been well tolerated in a long-term clinical study. The total daily dose should be divided in three single doses, the maximum time interval between doses should not exceed 12 hours.
It is not necessary to monitor gabapentin plasma concentrations to optimize gabapentin therapy. Further, gabapentin may be used in combination with other antiepileptic medicinal products without concern for alteration of the plasma concentrations of gabapentin or serum concentrations of other antiepileptic medicinal products.
Peripheral Neuropathic Pain
- The therapy may be initiated by titrating the dose as described in Table 1. Alternatively, the starting dose is 900 mg/day given as three equally divided doses. Thereafter, based on individual patient response and tolerability, the dose can be further increased in 300 mg/day increments every 2-3 days up to a maximum dose of 3600 mg/day. Slower titration of gabapentin dosage may be appropriate for individual patients.
- The minimum time to reach a dose of 1800 mg/day is one week, to reach 2400 mg/day is a total of 2 weeks, and to reach 3600 mg/day is a total of 3 weeks.
- In the treatment of peripheral neuropathic pain such as painful diabetic neuropathy and post-herpetic neuralgia, efficacy and safety have not been examined in clinical studies for treatment periods longer than 5 months. If a patient requires dosing longer than 5 months for the treatment of peripheral neuropathic pain, the treating physician should assess the patient’s clinical status and determine the need for additional therapy.
Instruction for all areas of indication
- In patients with poor general health, i.e., low body weight, after organ transplantation etc., the dose should be titrated more slowly, either by using smaller dosage strengths or longer intervals between dosage increases.
- Use in elderly patients (over 65 years of age)
- Elderly patients may require dosage adjustment because of declining renal function with age (see Table 2).
- Somnolence, peripheral oedema and asthenia may be more frequent in elderly patients.
Use in patients with renal impairment
Dosage adjustment is recommended in patients with compromised renal function as described in Table 2 and/or those undergoing haemodialysis. Gabapentin 100 mg capsules can be used to follow dosing recommendations for patients with renal insufficiency.
|DOSAGE OF GABAPENTIN IN ADULTS BASED ON RENAL FUNCTION|
|Creatinine Clearance (ml/min)||Total Daily Dosage (mg/day)|
- Total daily dose should be administered as three divided doses. Reduced dosages are for patients with renal impairment (creatinine clearance < 79 ml/min).
- To be administered as 300 mg every other day.
- For patients with creatinine clearance <15 ml/min, the daily dose should be reduced in proportion to creatinine clearance (e.g., patients with a creatinine clearance of 7.5 ml/min should receive one-half the daily dose that patients with a creatinine clearance of 15 ml/min receive).
Use in patients undergoing haemodialysis
- For anuric patients undergoing haemodialysis who have never received gabapentin, a loading dose of 300 to 400 mg, then 200 to 300 mg of gabapentin following each 4 hours of haemodialysis, is recommended.
- On dialysis-free days, there should be no treatment with gabapentin.
- For renally impaired patients undergoing haemodialysis, the maintenance dose of gabapentin should be based on the dosing recommendations found in Table 2. In addition to the maintenance dose, an additional 200 to 300 mg dose following each 4-hour haemodialysis treatment is recommended.
Other Usage OF This Medication
This drug may also be used for restless legs syndrome or other nerve pain conditions (such as diabetic neuropathy, peripheral neuropathy, trigeminal neuralgia).
Gabapentin 400 mg Side Effects
- Drowsiness, dizziness, loss of coordination, tiredness, blurred/double vision, unusual eye movements, or shaking (tremor) may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
- Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if any of these unlikely but serious side effects occur :- Swelling of the hands/ankles/feet
A small number of people who take anticonvulsants for any condition (such as seizures, bipolar disorder, pain) may experience depression, suicidal thoughts/attempts, or other mental/mood problems. Tell your doctor right away if you or your family/caregiver notice any unusual/sudden changes in your mood, thoughts, or behavior including signs of depression, suicidal thoughts/attempts, thoughts about harming yourself.
Get medical help right away if you have any very serious side effects, including: Slow / Shallow Breathing
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:
- swollen lymph nodes
- Itching/swelling (especially of the face/tongue/throat)
- Severe dizziness
- Trouble breathing
In the US
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345. (For Further Reference)
Before taking gabapentin 400 mg, tell your doctor or pharmacist if you are allergic to it; or to gabapentin enacarbil; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of:
- Kidney disease
- Mental / mood problems (such as depression, thoughts of suicide)
- Use/abuse of drugs/alcohol
- Breathing problems (such as COPD)
This drug may make you dizzy or drowsy or blur your vision. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Older adults may be more sensitive to the side effects of this drug, especially swelling of the hands/ankles/feet, slow/shallow breathing, dizziness, or loss of coordination. Dizziness and loss of coordination can increase the risk of falling.
Children may be more sensitive to the side effects of this drug, especially mental/mood/behavior changes (such as hostility, problems concentrating, restlessness).
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
Gabapentin passes into breast milk. Consult your doctor before breast-feeding.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor’s approval.
A product that may interact with this drug is: Orlistat
The risk of serious side effects (such as slow/shallow breathing, severe drowsiness/dizziness) may be increased if this medication is taken with other products that may also cause drowsiness or breathing problems. Tell your doctor or pharmacist if you are using other products such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as Carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).
Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.
Do not use this medication with other medications that contain gabapentin (including gabapentin enacarbil).
This medication may interfere with certain laboratory tests for urine protein. Make sure laboratory personnel and all your doctors know you use this drug.
f you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up. If you take gabapentin 3 times a day to control seizures, do not let more than 12 hours pass between doses because your seizures may increase. Consult your doctor right away if this occurs.
If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe drowsiness, trouble speaking, weakness.
The adverse reactions observed during clinical studies conducted in epilepsy (adjunctive and monotherapy) and neuropathic pain have been provided in a single list below by class and frequency (very common ( 1/10); common ( 1/100 to< 1/10); uncommon ( 1/1000 to < 1/100); rare ( 1/10000 to < 1/1000); very rare (< 1/10000). Where an adverse reaction was seen at different frequencies in clinical studies, it was assigned to the highest frequency reported.
Additional reactions reported from post-marketing experience are included as frequency Not known (cannot be estimated from the available data) in italics in the list below.
Within each frequency grouping, undesirable effects are presented in order of decreasing seriousness.
|Body System||Adverse drug reactions|
|Infections and infestations|
|Very Common||Viral infection|
|Common||Pneumonia, respiratory infection, urinary tract infection, infection, otitis media|
|Blood and the lymphatic system disorders|
|Immune system disorders|
|Uncommon||allergic reactions (e.g. urticaria)|
|Not Known||hypersensitivity syndrome (a systemic reaction with a variable presentation that can include fever, rash, hepatitis, lymphadenopathy, eosinophilia, and sometimes other signs and symptoms), anaphylaxis (see section 4.4)|
|Metabolism and Nutrition Disorders|
|Common||anorexia, increased appetite|
|Uncommon||hyperglycaemia (most often observed in patients with diabetes)|
|Rare||hypoglycaemia (most often observed in patients with diabetes)|
|Common||hostility, confusion and emotional lability, depression, anxiety, nervousness, thinking abnormal|
|Nervous system disorders|
|Very Common||somnolence, dizziness, ataxia|
|Common||convulsions, hyperkinesias, dysarthria, amnesia, tremor, insomnia, headache, sensations such as paresthesia, hypaesthesia, coordination abnormal, nystagmus, increased, decreased, or absent reflexes|
|Uncommon||hypokinesia, mental impairment|
|Rare||loss of consciousness|
|Not known||other movement disorders (e.g. choreoathetosis, dyskinesia, dystonia)|
|Common||visual disturbances such as amblyopia, diplopia|
|Ear and Labyrinth disorders|
|Respiratory, thoracic and mediastinal disorders|
|Common||dyspnoea, bronchitis, pharyngitis, cough, rhinitis|
|Common||vomiting, nausea, dental abnormalities, gingivitis, diarrhoea, abdominal pain, dyspepsia, constipation, dry mouth or throat, flatulence|
|Not known||hepatitis, jaundice|
|Skin and subcutaneous tissue disorders|
|Common||facial oedema, purpura most often described as bruises resulting from physical trauma, rash, pruritus, acne|
|Not known||Stevens-Johnson syndrome, angioedema, erythema multiforme, alopecia, drug rash with eosinophilia and systemic symptoms (see section 4.4)|
|Musculoskeletal, connective tissue and bone disorders|
|Common||arthralgia, myalgia, back pain, twitching|
|Not known||rhabdomyolysis, myoclonus|
|Renal and urinary disorder|
|Not known||acute renal failure, incontinence|
|Reproductive system and breast disorders|
|Not known||breast hypertrophy, gynaecomastia, sexual dysfunction (including changes in libido, ejaculation disorders and anorgasmia)|
|General disorders and administration site conditions|
|Very Common||fatigue, fever|
|Common||peripheral oedema, abnormal gait, asthenia, pain, malaise, flu syndrome|
|Not known||withdrawal reactions (mostly anxiety, insomnia, nausea, pains, sweating), chest pain. Sudden unexplained deaths have been reported where a causal relationship to treatment with gabapentin has not been established.|
|Common||WBC (white blood cell count) decreased, weight gain|
|Uncommon||elevated liver function tests SGOT (AST), SGPT (ALT) and bilirubin|
|Not known||blood glucose fluctuations in patients with diabetes, blood creatine phosphokinase increased|
|Injury, poisoning and procedural complications|
|Common||accidental injury, fracture, abrasion|