Gabutin

Gabapentin.

GABUTIN 100 MG CAPSULE: Each capsule contains Gabapentin 100 mg.
GABUTIN 300 MG CAPSULE: Each capsule contains Gabapentin 300 mg.
GABUTIN 600 MG TABLET: Each film-coated tablet contains Gabapentin 600 mg.

Pharmacology: Pharmacodynamics: Gabapentin is structurally related to GABA (gamma-aminobutyric acid). However, it does not bind to GABA_A or GABA_B receptors. High affinity gabapentin binding sites have been located throughout the brain where 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.
Pharmacokinetics: Absorption: When giving the drug 900, 1,200, 2,400, 3,600 and 4,800 mg per day (3 times per day), the bioavailability appears as 60%, 47%, 34%, 33% and 27% respectively. Food slightly effects on amount and rate of drug absorption by increasing 14% of AUC and C_max.
Distribution: Less than 3% of gabapentin circulate in blood as plasma protein binding. In patients with epilepsy, Gabapentin concentrations in cerebrospinal fluid (CSF) are approximately 20% of corresponding steady state through plasma concentrations.
Excretion: Gabapentin is eliminated by renal excretion as unchanged drug.

Epilepsy: Gabapentin is indicated as monotherapy in the treatment of partial seizures with and without secondary generalization in adults and children aged 12 years and older. Gabapentin is indicated as adjunctive therapy in the treatment of partial seizures with and without secondary generalization in adults and children aged 3 years and older.
Neuropathic pain: Gabapentin is indicated for treatment of neuropathic pain in patient aged 18 years and older.

Recommended dose and mode of administration: Epilepsy: Adults and children older than 12 years of age: A maintenance dosage is 900-3,600 mg/day. An initial dosage regimen is 300 mg 3 times on the first day or the dosage may be increased following Table 1, and up to 3,600 mg/day administered in 3 divided doses.
Doses up to 4,800 mg/day have been well tolerated in clinical studies. The maximum time between doses in the three times a day schedule should not exceed 12 hours to prevent breakthrough convulsions. (See Table 1.)

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Children 3-12 years: An initial dosage regimen is 10-15 mg/kg/day in 3 divided doses, the interval between doses should not exceed 12 hours; titrate to effective dose over approximately 3 days; dosages of up to 50 mg/kg/day have been tolerated in clinical studies.
In children 5-12 years of age, the maintenance dosage of Gabapentin is 25-35 mg/kg daily administered in 3 divided doses; for children 3-4 years of age, the dosage of Gabapentin is 40 mg/kg daily administered in 3 divided doses.
Neuropathic pain in adults: The starting dose is 900 mg/day given in three equally divided doses; the dosage may be increased following Table 1, and increased if necessary, based on response, up to a maximum dose of 3,600 mg/day. Therapy should be initiated by titrating the dose (three times a day).
Elderly: Studies in elderly patients have shown a decrease in clearance as age increases. This is most likely due to age-related decreases in renal function; dose reductions may be needed.
Renal function impairment: Dose adjustment is recommended in patients with compromised renal function and/or in those undergoing hemodialysis. (See Table 2.)

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Dose adjustment in patients undergoing hemodialysis: For patients undergoing hemodialysis who have never received Gabapentin, a loading dose of 300 mg to 400 mg is recommended, and then 200 mg to 300 mg of Gabapentin following each 4 hours of hemodialysis.
Hepatic function impairment: No information.

Symptoms: Acute overdoses of gabapentin up to 49 g have been reported. The symptoms including double vision, slurred speech, drowsiness, lethargy and diarrhea.
Treatment: Gabapentin can be removed by hemodialysis. Although hemodialysis has not been performed in the few overdose cases reported, it may be indicated by the patient's clinical state or in patients with significant renal impairment.

Gabapentin is contraindicated in patients who are hypersensitive to Gabapentin or any component of the formulation.

1. The drug may cause drowsiness, should not drive a vehicle or operate machinery. Do not take alcohol or alcoholic-containing product while using this drug.
2. The drug may cause hematologic disorder.
3. Do not use the drug in pregnant women because it may cause infant's morbidity.
4. Use the drug with caution in patients with liver and kidney disease.

Avoid abrupt withdrawal, may precipitate seizures.
Use cautiously in patients with severe renal dysfunction; male rat studies demonstrated an association with pancreatic adenocarcinoma.
May cause central nervous system depression, which may impair physical or mental abilities.
Patients must be cautioned about performing tasks which require mental alertness (e.g. operating machinery or driving).
Effects with other sedative drugs or ethanol may be potentiated.
Gabapentin is generally not considered effective in the treatment of absence seizures.
Gabapentin can cause severe systemic hypersensitivity reactions such as drug rash with eosinophilia and systemic symptoms (DRESS), anaphylaxis. Patients should be instructed to discontinue Gabapentin and seek immediate medical care should they experience signs or symptoms of them.
Use in Children: Pediatric patients (3-12 years of age) have shown increased incidence of central nervous system-related adverse effects, including emotional ability, hostility, thought disorder, and hyperkinesias.
Safety and efficacy of drug in patients aged less than 3 years old are still unknown.
Use in Pregnancy & Lactation: Gabapentin should be used during pregnancy only if the potential benefit to the mother clearly outweighs the potential risk to the fetus.
Gabapentin should be used in nursing mothers only if the benefits clearly outweigh the risks.

Pregnancy: Pregnancy Category C: Animal studies have documented teratogenic effects. There are no adequate and well-controlled studies in pregnant women. Use during pregnancy only if the potential benefit to the mother outweighs the potential risk to the fetus.
Lactation: The effect on the child is not known. Use in breast-feeding women only if the benefits to the mother outweigh the potential risk to the infant.

Table lists of sign and symptoms that occurred in at least 1% of patient with neuropathic pain participating in placebo-controlled studies that were numerically more frequent in the Gabapentin group than in the placebo group. Adverse effects in patients that received Gabapentin were usually reported as mild to moderate in intensity. (See Tables 3 and 4.)

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Table lists of adverse effects that occurred in at least 2% of Gabapentin treated in patients age 3 to 12 years of age with epilepsy participating in controlled studies that were numerically more frequent in the Gabapentin group than with placebo. Adverse effects in patients that received Gabapentin were usually reported as mild to moderate in intensity. (See Table 5.)

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Antacids: Co-administration of Gabapentin with antacid reduces Gabapentin bioavailability by about 20%.
Bioavailability of Gabapentin was reduced by 5% in 2 hours after antacid administration. It is recommended that Gabapentin should be taken at least 2 hours following antacid administration.
Cimetidine: Cimetidine seemed to alter the renal excretion of Gabapentin and creatinine. This is not expected to be of clinical importance.
Morphine: When 60 mg morphine was administered 2 hours prior to 600 mg oral Gabapentin, mean Gabapentin AUC increased by 44%. The magnitude of interaction at other doses is not known.
Oral contraceptive: Co-administration of Gabapentin with oral contraceptive containing norethindrone increased norethindrone AUC 13%, but it's not expected to be of clinical importance.
Naproxen: Co-administration of Gabapentin 125 mg with naproxen 250 mg capsule increased mean absorption of Gabapentin 12%-15%.
Ethanol: Ethanol may increase central nervous system depression.
Food: No significant effect on rate or extent of absorption.
Drug/lab test interaction: False positive have been reported with the Ames N-Multistix SG dipstick test when gabapentin was added to other anticonvulsant drugs. To determine urinary protein, the more specific sulfosalicylic acid precipitation procedure is recommended.
No pharmacokinetic interaction between Gabapentin and phenobarbital, phenytoin, valproic acid, or carbamazepine has been observed.

GABUTIN 100 MG & 300 MG CAPSULE: Store below 30°C.
GABUTIN 600 MG TABLET: Store below 25°C.

Anticonvulsants / Drugs for Neuropathic Pain

N02BF01 - gabapentin ; Belongs to the class of gabapentinoids. Used to relieve pain and other conditions.

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