Western Medicine Carbamazepine Tablets (Psychiatric drugs ,Sodium
Carbamazepine (CBZ), sold under the tradename Tegretol among others, is a medication used primarily in the treatment of epilepsy and neuropathic pain.It is not effective for absence seizures or myoclonic seizures. It is used in schizophrenia along with other medications and as a second line agent inbipolar disorder.Carbamazepine appears to work as well as phenytoin and valproate.
Common side effects include nausea and drowsiness. Serious side effects may include skin rashes, decreased bone marrow function, suicidal thoughts, or confusion. It should not be used in those with a history of
bone marrow problems. Use during pregnancy may cause harm to the baby; however stopping it in pregnant women
with seizures is not recommended. Its use during breastfeeding is not recommended. Care should be taken in those with either
kidney or liver problems.
Medical usesTegretol 200-mg CR (made in NZ)
Carbamazepine is typically used for the treatment of seizure disorders and neuropathic pain. It is used off-label as a second-line treatment for bipolar disorder and in combination
with an antipsychotic in some cases of schizophrenia when treatment with a conventional antipsychotic alone has failed.
It is not effective for absence seizures or myoclonic seizures.
In the United States, the FDA-approved medical uses are epilepsy (including partial seizures, generalized tonic-clonic seizures and mixed seizures),trigeminal neuralgia, and manic and mixed episodes of bipolar I disorder.
As of 2014 a controlled release formulation was available for which there is tentative evidence
showing fewer side effects and unclear evidence with regard to
whether there is a difference in efficacy.needs update]
In the US, the label for carbamazepine contains warnings
Common adverse effects may include drowsiness, dizziness, headaches and migraines, motor coordination impairment, nausea, vomiting, and/or constipation. Alcohol use
while taking carbamazepine may lead to enhanced depression of the central nervous system. Less common side effects may include increased risk of seizures
in people with mixed seizure disorders,abnormal heart rhythms, blurry or double vision.Also, rare case reports of an auditory side effect have been made,
whereby patients perceive sounds about a semitone lower than previously; this unusual side effect is usually not
noticed by most people, and disappears after the person stops
Carbamazepine has a potential for drug interactions; caution should be used in combining other medicines with it,
including other antiepileptics and mood stabilizers.Lower levels of
carbamazepine are seen when administrated with phenobarbital, phenytoin, or primidone, which can result in breakthrough seizure activity. Carbamazepine,
as a CYP450 inducer, may increase clearance of many drugs, decreasing their
concentration in the blood to subtherapeutic levels and reducing
their desired effects.Drugs that are more rapidly metabolized with
carbamazepine include warfarin, lamotrigine, phenytoin,theophylline, and valproic acid. Drugs that decrease the metabolism of carbamazepine or otherwise
increase its levels include erythromycin,cimetidine, propoxyphene, and calcium channel blockers.Carbamazepine also increases the metabolism of the hormones in birth control pills and can reduce their effectiveness, potentially leading to
unexpected pregnancies.As a drug that induces cytochrome P450
enzymes, it accelerates elimination of many benzodiazepines and
decreases their action.
Valproic acid and valnoctamide both inhibit microsomal epoxide hydrolase (MEH), the enzyme responsible for the breakdown of
carbamazepine-10,11 epoxide into inactive metabolites.By inhibiting
MEH, valproic acid and valnoctamide cause a build-up of the active
metabolite, prolonging the effects of carbamazepine and delaying
Grapefruit juice raises the bioavailability of carbamazepine by inhibiting CYP3A4 enzymes in the gut wall and
in the liver.Carbamazepine increases the processing of methadone resulting in lower blood levels.
Dangerous and potentially fatal skin reactions, including Stevens–Johnson syndrome and toxic epidermal necrolysis, caused by carbamazepine therapy are significantly more common in
patients with a particular human leukocyte antigen allele, HLA-B*1502. Odds ratios for the development of Stevens-Johnson syndrome or toxic epidermal necrolysis in patients who carry the allele can be in the double, triple or
even quadruple digits, depending on the population studied. HLA-B*1502 occurs almost exclusively in patients with ancestry across broad
areas of Asia, but has a very low or absent frequency in European,
Japanese, Korean and African populations.However, the HLA-A*31:01
allele has been shown to be a strong predictor of both mild and
severe adverse reactions to carbamazepine among Japanese and
Carbamazepine is relatively slowly but well absorbed after oral
administration. Its plasma half-life is about 30 hours when it is
given as single dose, but it is a strong inducer of hepatic enzymes
and the plasma half-life shortens to about 15 hours when it is
given repeatedly.[medical citation needed]
[Mechanism of action]
The mechanism of action of carbamazepine and its derivatives is
relatively well understood.[medical citation needed] Carbamazepine is a use-dependant blocker of voltage-gated sodium
channels. It is ionised within intracellular fluid, and is then
able to bind to activated voltage-gated sodium channels, preventing
repetitive and sustained firing of an action potential.This leaves
the affected cells less excitable until the drug dissociates.
Carbamazepine is also a GABA receptor agonist, as it has also been shown to potentiate GABA receptors made up of alpha1, beta2, and gamma2 subunits. This mechanism may contribute to its efficacy in neuropathic pain
and bipolar disorder. Laboratory research has further demonstrated
that carbamazepine is a serotonin releasing agent and possibly even a serotonin reuptake inhibitor.
Patients with atrioventricular block, severe iron deficiency, bone
marrow suppression, severe liver dysfunction, and so on.
|Pregnant and lactating women||Can be through the placenta, whether or not teratogenic is still
not clear, early pregnancy should be used with caution; this
product can be secreted into the milk, about 60% of the plasma
concentration, lactating women should not be applied.|
|Child medication||Can be used for children of all ages, specific reference.|
|Elderly medication||Elderly patients more sensitive to the chemicals, often can cause
cognitive dysfunction, agitation, restlessness, anxiety, mental
disorder, atrioventricular block or bradycardia, also can cause
Store in a cool,dry place below 30 degrees.
Protect from light.
Keep all medicines out of reach of children.