Mood Stabilizers as Medications carbamazepine, Tegretol
Mood stabilizer: carbamazepine, Tegretol
Generic Name: carbamazepine
Anticonvulsant - Trigeminal Neuralgia Therapy - Antimanic
Brand Name(s): Tegretol
Common Use: Mood stabilizer
Carbamazepine has anticonvulsant properties which have been found useful in
the treatment of psychomotor epilepsy and as an adjunct in the treatment of
partial epilepsies, when administered in conjunction with other anticonvulsant
drugs to prevent the possible generalization of the epileptic discharge. A mild
psychotropic effect has been observed in some patients, which seems related
to the effect of the carbamazepine in psychomotor or temporal lobe epilepsy.
Carbamazepine given as a monotherapy or in combination with lithium or neuroleptics
has been found useful in the treatment of acute mania and the prophylactic treatment
of bipolar (manic-depressive) disorders.
Like other tricyclic compounds, carbamazepine has a moderate anticholinergic
action which is responsible for some of its adverse effects. A tolerance may
develop to the action of carbamazepine after a few months of treatment and should
be watched for.
Treatment of Acute Mania and Prophylaxis in Bipolar (Manic-Depressive) Disorders:
Carbamazepine may be used as a monotherapy or as an adjunct to lithium in the
treatment of acute mania or prophylaxis of bipolar (manic-depressive) disorders
in patients who are resistant to or are intolerant of conventional antimanic
drugs. Carbamazepine may be a useful alternative to neuroleptics in such patients.
Patients with severe mania, dysphoric mania or rapid cycling who are non-responsive
to lithium may show a positive response when treated with carbamazepine. It
is important to note that these recommendations are based on extensive clinical
experience and some clinical trials versus active comparison agents.
Should not be administered to patients with a history of hepatic disease, acute
intermittent porphyria or serious blood disorder.
The drug should not be administered immediately before, in conjunction with,
or immediately after an MAO inhibitor. When it seems desirable to administer
carbamazepine to a patient who has been receiving an MAO inhibitor, there should
be as long a drug-free interval as the clinical condition allows, but in no
case should this be less than 14 days. Then the dosage of carbamazepine should
be low initially, and increased very gradually.
The reactions which have been most frequently reported with carbamazepine are
CNS (e.g., drowsiness, headache, unsteadiness on the feet, diplopia, dizziness),
gastrointestinal disturbances (nausea, vomiting), as well as allergic skin reactions.
These reactions usually occur only during the initial phase of therapy, if the
initial dose is too high, or when treating elderly patients. They have rarely
necessitated discontinuing carbamazepine therapy and can be minimized by initiating
treatment at a low dosage.
The occurrence of CNS adverse reactions may be a manifestation of relative
overdosage or significant fluctuation in plasma levels. In such cases it is
advisable to monitor the plasma levels and possibly lower the daily dose and/or
divide it into 3 to 4 fractional doses. The more serious adverse reactions observed
are the hematologic, hepatic, cardiovascular and dermatologic reactions, which
require discontinuation of therapy. If treatment with carbamazepine has to be
withdrawn abruptly, the change-over to another antiepileptic drug should be
effected under cover of diazepam.
The following adverse reactions have been reported:
Occasional or frequent: Leukopenia. Occasional: Eosinophilia, thrombocytopenia.
Rare: Leukocytosis, lymphadenopathy. Isolated cases: Agranulocytosis, aplastic
anemia, pure red cell aplasia, macrocytic anemia, acute intermittent porphyria,
reticulocytosis, folic acid deficiency, thrombocytopenic purpura, and possibly
hemolytic anemia. In a few instances, deaths have occurred. Occasional to frequent:
Skin sensitivity reactions and rashes, erythematous rashes, urticaria. Rare:
Exfoliative dermatitis and erythroderma, Stevens-Johnson syndrome, systemic
lupus erythematosus-like syndrome. Isolated cases: toxic epidermal necrolysis
(Lyell's syndrome), photosensitivity, erythema multiform and nodosum, skin pigmentation
changes, pruritus, purpura, acne, diaphoresis, alopecia and neurodermatitis.
Frequent: Vertigo, somnolence, ataxia and fatigue. Occasionally: An increase
in motor seizures (see Indications), headache, diplopia, nystagmus, accommodation
disorders (e.g., blurred vision). Rare: Abnormal involuntary disorders (e.g.,
tremor, asterixis, orofacial dyskinesia, choreoathetosis disorders, dystonia,
tics). Isolated cases: Oculomotor disturbances, speech disorders (e.g., dysarthria
or slurred speech), peripheral neuritis, paresthesia. There have been some reports
of paralysis and other symptoms of cerebral arterial insufficiency but no conclusive
relationship to the administration of carbamazepine could be established. Disturbances
of cardiac conduction, bradycardia, arrhythmias, Stokes-Adams in patients with
AV block, congestive heart failure, hypertension or hypotension, aggravation
of coronary artery disease, thrombophlebitis, thromboembolism. Some of these
complications (including myocardial infarction and arrhythmia) have been associated
with other tricyclic compounds. Isolated cases: Hallucinations (visual or acoustic),
depression, sometimes with talkativeness, agitation, loss of appetite, restlessness,
aggressive behaviour, confusion, activation of psychosis. Isolated cases: Interstitial
nephritis and renal failure, as well as signs of renal dysfunction (e.g., albuminuria,
glycosuria, hematuria, oliguria sometimes associated with elevated blood pressure,
and elevated BUN/azotemia), urinary frequency, urinary retention and renal failure.
Isolated reports: Sexual disturbances/impotence. Occasional or frequent: Nausea,
vomiting. Occasional: Dryness of the mouth and throat. Rare: Diarrhea or constipation.
Isolated cases: Abdominal pain, glossitis, stomatitis, anorexia. Isolated cases:
Lens opacities, conjunctivitis, retinal changes, tinnitus, hyperacusis and taste
disturbances. Occasionally edema, fluid retention, weight increase, hyponatremia
and reduced plasma osmolality due to antidiuretic hormone (ADH)-like effect
occurs, leading in isolated cases to water intoxication accompanied by lethargy,
vomiting, headache, mental confusion and neurological abnormalities. Isolated
cases of gynecomastia or galactorrhea have been reported, as well as abnormal
thyroid function tests (decreased L-thyroxine, i.e., FT(4), T(4), T(3), and
increased TSH, usually without clinical manifestations), disturbances of bone
metabolism (decrease in plasma calcium and 25-OH-calciferol), leading in isolated
cases to osteomalacia, as well as reports of elevated levels of cholesterol,
including HDL cholesterol and triglycerides. Isolated cases: Arthralgia, muscle
pain or cramp. Isolated cases: Pulmonary hypersensitivity characterized by fever,
dyspnea, pneumonitis or pneumonia. A rare delayed multi-organ hypersensitivity
disorder with fever, skin rashes, vasculitis, lymphadenopathy, disorders mimicking
lymphoma, arthralgia, leukopenia, eosinophilia, hepato-splenomegaly and abnormal
liver function tests, occurring in various combinations. Other organs may also
be affected (e.g., lungs, kidneys, pancreas, myocardium). Isolated cases: Aseptic
meningitis, with myoclonus and eosinophilia; anaphylactic reaction. Treatment
should be discontinued should such hypersensitivity reactions occur.
The presenting signs and symptoms of overdosage usually involve the
central nervous, cardiovascular and respiratory systems. CNS depression, disorientation,
tremor, restlessness, somnolence, agitation, hallucination, coma, blurred vision,
nystagmus, mydriasis, slurred speech, dysarthria, ataxia, dyskinesia, abnormal
reflexes (slowed/hyperactive), convulsions, psychomotor disturbances, myoclonus,
opisthotonia, hypothermia/hyperthermia, flushed skin/cyanosis, EEG changes.There
is no known specific antidote to carbamazepine.
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