GABAMED 400

• Therapeutic Category
  • ANTIEPILEPTICS&ANTICONVULSANTS
• Pharmaceutical Form : Capsules
• Composition : Gabapentin 400 mg / Cap
• Active Substance : Gabapentin

CLINICAL PHARMACOLOGY  :

 Gabamed is  an anticonvulsant antineureigic agent structurally related to the inhibtory CNS

Neurotransmitter gamma-aminobutyric acid (GABA).

Although Gabapentin was deveioped as a structural anaiog of GABA that penetrate the blood-brain

Barrier (unlike GABA ) and mimic the action of GABA at inhibitory neuronal synapsis,

Gabapentin has no direct GABA-mimetic action and its precise mechanism of action has not been elucidated in rats , Gabapentin interacts with a novel-binding sites on cotical neurons that may be associated with the L-system amino acid transporter of brain cell membranes .

Gabapentin is absorbed rapidly , as the dose increases, bioavailability decreases .

The entire absorbed dose is eliminated renaly as unchanged drug .

Indications :

 Gabamed is indicated in the treatment of :

• Epilepsy
• As monotherapy in patients with newly diagnosed seizures .
• As an adjunct to other anticonvuisant medications in the treatment of partial seizures with or

  without seconday generalization in adults and children 3 years of age and above .

• Postherpetic neuralgia in adults .
• Diabetic peripheral neuropathic pain in adults .

Side effects :

Side effects due to Gabapentin therapy are generally mild to moderate in severity , and tend to diminish

With continued use .

More frequent effects : Ataxia ,nystagmus, dizziness, fatigue, myaigia, peripheral edema, somnolence

Which may be dose-related, tremor, vision abnormalities, including blurred vision, and dipiopia.

In pediatric patients 3 to 12 years age : neuropsychiatric problems, including emotional lability , hostility,

Hyperkinesias, and thought disorders.

Less frequent effects : Amnesia, depression, irritability, or other mood or mental changes, asthenia,

Back pain, dryness of mouth or throat, dysarthria, frequent urination, gastrointestinal effects, including

Constipation, diarrhea, dyspepsia, nausea and vomiting, headache, hypotension, impotence, insomnia,

Rhinitis, tinnitus, trouble in thinking, twitching, weight gain .

Contraindications :

• Hypersensitivity to Gabapentin .
• In patients with acute pancreatitis.
• Primarily generalized seizures, such as absences .

Warnings :

Antiepileptic drugs should not be abruptly discontinued because  of the possibility of increasing seizure

Frequency, and the possibility of pancreatitis.

Drug interactions :

• Gabapentin does not induce or inhibit the hepatic mixed oxidase enzymes responsible for drug

metabolism. Also, it does not interfere with the metabolism of commonly coadministered

antiepileptic agents .

• Antacids, especially containing aluminum and magnesium, reduce the bioavailability of Gabamed

by 20% . It is recommended that Gabamed be taken at least 2 hours following antacids administration.

Interference with clinical and laboratory tests :

• Gabamed causes a false positive result for dipstick test for urinary protein ; the sulfosalicylic acid

precipitation procedure should be used to detect urinary protein .

• White blood cell counts may be decreased .

 Use in pregnancy :

 Adequate and well-controlled studies has not been done in humans, Gabapentin should be used during

 Pregnancy only if the benefit justifies the potential risk to the fetus. FDA Pregnancy Category C.

Gabamed is secreted into human milk following oral administration. Because of the potential for serious

Side effects to Gabamed in nursing infants, a decision should be made whether to discontinue nursing

or the drug, taking into account the importance of the drug to the woman .

Dosage :

Usual dose for adults and children 12 years of age and over :

1- Epilepsy

   Initially 300 mg 3 times daily . the dosage may be gradually increased based on clinical response.

   Dosages of 900 to 1800 mg daily in 3 divided doses are effective for most patients . However, dosages

   as high as 2400 to 3600 mg in 3 divided doses have been well tolerated .

2- Postherpetic Neuralgia :

   900 mg daily in 3 divided doses. The dose can subsequently be titrated up as needed for pain relief

   to a daily dose of 1800 mg in 3 divided doses. In clinical studies, efficacy was demonstrated over a

   range of doses from 1800 to 3600 mg / day with comparable effects across the dose range .

   additional benefit of using doses greater than 1800 mg/ day was not demonstrated .

3- Diabetic peripheral neuropathic pain :

   Initially 900 mg daily titrated to a maximum of 3600 mg daily in 3 divided doses .

Usual pediatric dose ( 3 – 12 years ).

Epilepsy :

The starting dose should range from 10 – 15 mg/day in 3 divided doses, and the effective dose could

be reached by upward titration over a period of approximately 3 days .

• Ages 5 years and older : The effective dose is 25 – 35 mg / day given in 3 divided doses .
• Ages 3 years and 4 years : The effective dose is 40 mg/kg /day given in 3 divided doses .

Gabamed dosages up to 50mg/kg/day have been well tolerated in a long-term clinical study.

Notes :

• In case of epilepsy, postherpelic neuralgia and neuropathic pain in adults , the dose may be titrated gradually within the first 3 days treatment to 900 mg/day as the following dose scheme :

Day 1	1 Gabamed 300 mg capsule, once daily ( 300 mg Gabapentin/day ).
Day 2	1 Gabamed 300 mg capsule, twice daily ( 600 mg Gabapentin/day ).
From Day 3 onwards	1 Gabamed 300 mg capsule, 3 times daily ( 90 mg Gabapentin/day ).

• When taking Gabamed 3 times daily ,the interval between doses should not exceed 12 hours.
• For patients ³ 12years of age and undergoing hemodialysis : 300 mg to 400 mg initially for patients

Who have never received Gabamed , then 200 to 300 mg following each 4 hours of hemodialysis.

• The use of Gabamed in patients Ð12 years of age with impaired renal function has not been studied .
• Because elderly patients are more likely to have impaired renal function, care should be taken in dose selection, and dose should be adjusted based on creatinine clearance values .
• Gabamed may be taken with or without food .
• Usual adults and adolescentsprescribed doses limit is 3600 mg per day.
• The duration of treatment is depending on clinical requirements. In treatment of epilepsy ,long term therapy is normally required .
• Adults with impaired renal function may require a reduction in dose as follows :

Renal Function Creatinine clearance (ml/min )	Total Daily DoseRange (mg/day)	Dose Regimen (mg )
³ 60	900-3600	300 TID	400 TID	600 TID	800 TID	1200 TID
ñ 30-59	400-1400	200 BID	300 BID	400 BID	500 BID	700 BID
ñ 15-29	200-700	200 QD	300 QD	400 QD	500 QD	700 QD
Ð 15	100-300	100QD	125 QD	150 QD	200 QD	300 QD

Overdose :

Symptoms of overdose include dizziness, diplopia, dysarthria, sedation, and mild diarrhea.

Acute life-threatening toxicity has not been observed with Gabamed overdoses of up to 49g per day.

Although, Gabamed can be removed by hemodialysis, experience has shown this to be normally unnecessary .

However, hemodialysis may be indicated in patients with renal impairment .

Precautions :

• Discuse alcohol use or use of other CNS depressants with your physician .
• Caution should be taken when driving or doing jobs require alertness.

Packing :

• Gabamed 300 mg Capsules :box of 20 capsules .
• Gabamed 400 mg Capsules :box of 20 capsules .

Store conditions :

Store at a dry place between 15°C- 30°C .