How Oxcarbazepine and Gabapentin work?
Oxcarbazepine belongs to the class of drugs called anticonvulsants, or antiepileptic drugs which works by decreasing abnormal electrical activity or nerve impulses responsible for causing seizures. Oxcarbazepine is used for the management of certain types of seizures. The drug is sometimes used as a mood stabilizer.
The exact mechanism of action by which Oxcarbazepine put forth its anticonvulsant or antiseizure effect is unknown. However, studies indicate that the pharmacological activity of Oxcarbazepine is primarily exerted through its 10-monohydroxy metabolite (MHD).
MHD causes a blockade of voltage-sensitive sodium channels which results in stabilization of hyperexcited neural membranes, inhibition of repetitive neuronal firing, and reduction of propagation of synaptic impulses.
These actions play important role in the prevention of seizure spread in the intact brain. Besides this, increased potassium conductance and modulation of high-voltage activated calcium channels may also be responsible for the anticonvulsant effects of the drug. Oxcarbazepine or MHD has not been shown to have any significant interactions with brain neurotransmitter or modulator receptor sites.
Gabapentin belongs to the class of drugs that commonly known as anticonvulsant or antiepileptic drugs. Gabapentin is prescribed to treat certain types of seizures in patients with epilepsy. The precise mode of action of Gabapentin is not known. It is suggested that Gabapentin exert its effect through its interaction with voltage-sensitive Ca2+ channels in brain membranes.
It has been observed that Gabapentin can easily cross lipid membrane and amends the effect of the glutamic acid decarboxylase(GABA synthetic enzyme) and the amino acid transaminase (glutamate synthesizing enzyme) . This results in an increased synthesis of GABA neurotransmitter and increased non-synaptic GABA responses from neuronal tissues.
Overall it also reduced the secretion of several mono-amine neurotransmitters in the brain tissues. Besides this, Gabapentin also exert its effects through its interaction with presynaptic NMDA receptors. Binding of Gabapentin with NMDA presynaptic receptors results in reduction of the axon excitability in the hippocampus.
Furthermore, antihyperalgesic and antiallodynic properties of Gabapentin are primarily through activation of the downward pain inhibitory system also known as noradrenergic system. Apart from this some other mechanisms of Gabapentin mode of action involved binding to the adenosine A1 receptor, inflammatory cytokines and protein kinase C.
Can both Oxcarbazepine and Gabapentin be taken together in combination?
Yes, both the drugs can be used in combination for their anti-seizure effect. Studies indicate that the combination of Oxcarbazepine and Gabapentin in various fixed ratio combinations (1:1, 1:2, 1:5, 1:10, 1:15, and 1:20) exerts supra-additive (synergistic) interactions against electroconvulsions in mouse maximal electroshock seizure model.
Besides, the combinations of Oxcarbazepine with Gabapentin result in no change in motor performance of the animals administered at their median effective doses. In addition, the co-administration of Gabapentin and Oxcarbazepine does not affect the total brain concentrations of either drug. Studies indicate prospects of the combination of Oxcarbazepine and Gabapentin for further therapy in patients with refractory partial seizures.
SUNCT (Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing Syndrome), a syndrome of intermittent, brief, unilateral, severe paroxysms of orbital-temporal pain recurring multiple times per day has been successfully treated with the combination of Oxcarbazepine and Gabapentin which is often very difficult to control by other means.
Safety and precautions while taking Oxcarbazepine: Gabapentin combination
- Oxcarbazepine and Gabapentin may interact with other drugs. Therefore, care should be taken when you are taking any prescription or non-prescription medicines and herbal or vitamin supplements. It is advisable that you do not start, stop or change or take any medicine unless you have discussed with your doctor or professional consult.
- Do not use the medicine if you are hypersensitive or allergic (e.g., anaphylaxis) to Oxcarbazepine or Gabapentin, or any of the drug constituents.
- Do not share the medications with other persons having the similar kind of problems. Consult your doctor for more details.
- Oxcarbazepine and Gabapentin use is not recommended during driving or operating heavy machines as they may cause the patient drowsy and dizzy, and also result in decreasing their thinking and cause loss of coordination.
- Gabapentin should be avoided during breast feeding as it can pass into breast milk and may harm a nursing baby. Oxcarbazepine is also not recommended during breast feeding.
- Regular visits are required during administration of Oxcarbazepine and Gabapentin as they may result in development of suicidal thoughts in some people.
- Oxcarbazepine administration may cause harm to the fetus and should not be used during pregnancy. Gabapentin is also not recommended for use during pregnancy.
- Use of alcohol is not recommended during the administration of these medications.
- Oxcarbazepine may result in serious life-threatening skin rash. It is therefore advised to consult the doctor in case of fever, unusual weakness, bleeding, or a skin rash during the use of the drug.
- Oxcarbazepine should be used with caution in case of elderly and children below 2 years of age.