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Drug Details

Gabapentin 100 mg Capsules

• Drug Class Description
  Other antiepileptics - ATC code: N03AX12
• Generic Name
  gabapentin
• Presentation
  Capsule, hard Hard gelatin capsule (size 3), with white opaque body and cap.
• Description
  Each capsule contains 100mg of gabapentin
• Indications
  

  Epilepsy

  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.

  Gabapentin 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.

• Adult Dosage
  

  For oral use.

  Gabapentin can be given with or without food and should be swallowed whole with sufficient fluid-intake (e.g. a glass of water).

  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.

  Table 1
  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

  Epilepsy

  Epilepsy typically requires long-term therapy. Dosage is determined by the treating physician according to individual tolerance and efficacy. When in the judgment of the clinician there is a need for dose reduction, discontinuation, or substitution with an alternative medication, this should be done gradually over a minimum of one week.

  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.

  Peripheral neuropathic pain

  Adults

  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 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.

  Table 2
  Dosage of Gabapentin in Adults Based on Renal Function
  Creatinine Clearance (ml/min)	Total Daily Dosea (mg/day)
  80	900-3600
  50-79	600-1800
  30-49	300-900
  15-29	150b-600
  <15c	150b-300

  ^a Total daily dose should be administered as three divided doses. Reduced dosages are for patients with renal impairment (creatinine clearance < 79 ml/min).

  ^b To be administered as 300 mg every other day.

  ^c 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.

• Child Dosage
  

  Epilepsy

  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.

• Elderly Dosage
  

  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.

• Contra Indications
  

  Hypersensitivity to the active substance or to any of the excipients.

• Special Precautions
  

  If a patient develops acute pancreatitis under treatment with gabapentin, iscontinuation of gabapentin should be considered.

  Although there is no evidence of rebound seizures with gabapentin, abrupt withdrawal of anticonvulsants in epileptic patients may precipitate status epilepticus.

  As with other antiepileptic medicinal products, some patients may experience an increase in seizure frequency or the onset of new types of seizures with gabapentin.

  As with other anti-epileptics, attempts to withdraw concomitant anti-epileptics in treatment refractory patients on more than one anti-epileptic, in order to reach gabapentin monotherapy have a low success rate.

  Gabapentin is not considered effective against primary generalized seizures such as absences and may aggravate these seizures in some patients. Therefore, gabapentin should be used with caution in patients with mixed seizures including absences.

  No systematic studies in patients 65 years or older have been conducted with gabapentin. In one double blind study in patients with neuropathic pain, somnolence, peripheral oedema and asthenia occurred in a somewhat higher percentage in patients aged 65 years or above, than in younger patients. Apart from these findings, clinical investigations in this age group do not indicate an adverse event profile different from that observed in younger patients.

  The effects of long-term (greater than 36 weeks) gabapentin therapy on learning, intelligence, and development in children and adolescents have not been adequately studied. The benefits of prolonged therapy must therefore be weighed against the potential risks of such therapy.

  Suicidal ideation and behaviour have been reported in patients treated with antiepileptic agents in several indications. A meta-analysis of randomised placebo controlled trials of anti-epileptic drugs has also shown a small increased risk of suicidal ideation and behaviour. The mechanism of this risk is not known and the available data do not exclude the possibility of an increased risk for gabapentin. Therefore patients should be monitored for signs of suicidal ideation and behaviours and appropriate treatment should be considered. Patients (and caregivers of patients) should be advised to seek medical advice should signs of suicidal ideation or behaviour emerge.

  Laboratory tests

  False positive readings may be obtained in the semi-quantitative determination of total urine protein by dipstick tests. It is therefore recommended to verify such a positive dipstick test result by methods based on a different analytical principle such as the Biuret method, turbidimetric or dye-binding methods, or to use these alternative methods from the beginning.

• Interactions
  

  In a study involving healthy volunteers (N=12), when a 60 mg controlled-release morphine capsule was administered 2 hours prior to a 600 mg gabapentin capsule, mean gabapentin AUC increased by 44% compared to gabapentin administered without morphine. Therefore, patients should be carefully observed for signs of CNS depression, such as somnolence, and the dose of gabapentin or morphine should be reduced appropriately.

  No interaction between gabapentin and phenobarbital, phenytoin, valproic acid, or carbamazepine has been observed.

  Gabapentin steady-state pharmacokinetics are similar for healthy subjects and patients with epilepsy receiving these antiepileptic agents.

  Coadministration of gabapentin with oral contraceptives containing norethindrone and/or ethinyl estradiol, does not influence the steady-state pharmacokinetics of either component.

  Coadministration of gabapentin with antacids containing aluminium and magnesium, reduces gabapentin bioavailability up to 24%. It is recommended that gabapentin be taken at the earliest two hours following antacid administration.

  Renal excretion of gabapentin is unaltered by probenecid.

  A slight decrease in renal excretion of gabapentin that is observed when it is coadministered with cimetidine is not expected to be of clinical importance.

• Adverse Drug Reactions
  

  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 (1/10,000 to <1/1,000), very rare (<1/10,000), not known (cannot be estimated from the available data). Where an adverse reaction was seen at different frequencies in clinical studies, it was assigned to the highest frequency reported.

  Within each frequency grouping, undesirable effects are presented in order of decreasing seriousness.

  Infections and infestations
  Very Common:	Viral infection
  Common:	Pneumonia, respiratory infection, urinary tract infection, infection, otitis media
  Blood and the lymphatic system disorders
  Common:	Leucopenia
  Rare:	Thrombocytopenia
  Immune system disorders
  Rare:	Allergic reactions (e.g. urticaria)
  Metabolism and Nutrition Disorders
  Common:	Anorexia, increased appetite
  Psychiatric disorders
  Common:	Hostility, confusion and emotional lability, depression, anxiety, nervousness, thinking abnormal
  Rare:	Hallucinations
  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
  Rare:	Movement disorders (e.g. choreoathetosis, dyskinesia, dystonia)
  Eye disorders
  Common:	Visual disturbances such as amblyopia, diplopia
  Ear and Labyrinth disorders
  Common:	Vertigo
  Rare:	Tinnitus
  Cardiac disorders
  Rare:	Palpitations
  Vascular disorder
  Common:	Hypertension, vasodilatation
  Respiratory, thoracic and mediastinal disorders
  Common:	Dyspnoea, bronchitis, pharyngitis, cough, rhinitis
  Gastrointestinal disorders
  Common:	Vomiting, nausea, dental abnormalities, gingivitis, diarrhea, abdominal pain, dyspepsia, constipation, dry mouth or throat, flatulence
  Rare:	Pancreatitis
  Hepatobiliary disorders
  Rare:	Hepatitis, jaundice
  Skin and subcutaneous tissue disorders
  Common:	Facial oedema, purpura most often described as bruises resulting from physical trauma, rash, pruritus, acne
  Rare:	Stevens-Johnson syndrome, angioedema, erythema multiforme, alopecia
  Musculoskeletal, connective tissue and bone disorders
  Common:	Arthralgia, myalgia, back pain, twitching
  Renal and urinary disorders
  Common:	Incontinence
  Rare:	Acute renal failure
  Reproductive system and breast disorders
  Common:	Impotence
  General disorders and administration site conditions
  Very Common:	Fatigue, fever
  Common:	Peripheral or generalized oedema, abnormal gait, asthenia, pain, malaise, flu syndrome
  Rare:	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.
  Investigations
  Common:	WBC (white blood cell count) decreased, weight gain
  Rare:	Blood glucose fluctuations in patients with diabetes, elevated liver function tests
  Injury and poisoning
  Common:	Accidental injury, fracture, abrasion

  Under treatment with gabapentin cases of acute pancreatitis were reported. Causality with gabapentin is unclear.

  Respiratory tract infections, otitis media, convulsions and bronchitis were reported only in clinical studies in children. Additionally, in clinical studies in children, aggressive behaviour and hyperkinesias were reported commonly.