CARBAMAZEPINE THERAPY

What is Manic Depression?

Manic Depressive illness is marked by severe and often dramatic mood swings. These consist usually of periods of mania, which fluctuate with periods of depression and periods of stability during which the sufferer often behaves and reacts in a perfectly normal manner. Some of the more common symptoms of mania and depression are listed below.

What is Carbamazepine?

Carbamazepine is used to treat patients with manic depressive disorder who fail to respond satisfactorily to other treatments such as lithium or who cannot tolerate those treatments. Carbamazepine may be used on its own or together with lithium. Carbamazepine is also used to treat epilepsy and pain syndromes.

Does Carbamazepine cure manic depressive disorder?

No, but it is one effective way to control it. It is thought to restore normal activity to brain chemicals. Carbamazepine may be of help in two ways.

1. Stopping an acute episode carbamazepine can help a person out of a state of mania back to a normal state. It may also be effective in some cases of acute depression.

2. Preventing further episodes carbamazepine can help prevent episodes of mania and depression from recurring.

Many people with manic depressive disorder experience frequent episodes of mania and depression before beginning treatment with carbamazepine. If they stop taking carbamazepine, they will almost certainly have frequent episodes again. The manic depressive disorder would no longer be controlled.

Some people with manic depressive disorder experience several episodes of mania and depression a year. People who have four or more episodes per year are called "rapid cyclers" and often do not respond to treatment with lithium alone. Carbamazepine may be especially helpful in treating these patients. Some people with manic depressive disorder however, experience infrequent episodes of mania and depression often years apart. Others have only one of a few such episodes and no further recurrences. Why this happens is as much a mystery as the cause of the illness itself!

Beginning Carbamazepine

Before beginning carbamazepine therapy it will be necessary to consult closely with your doctor to ensure they will be able to treat you safely and effectively. Some of the information your doctor will need includes:

Your medical history: do you have any other medical conditions such as heart disease, liver disease, epilepsy anaemia or other blood diseases, glaucoma or diabetes? Do you have any allergic reactions to medication? Do you have any family history of psychiatric disorders, especially mania or depression.

Your normal diet: do you drink large amounts of coffee or tea? How much alcohol do you consume? Are you on a special diet? Do you plan beginning any special diet in the future?

Your occupation and activities: Do you need to operate dangerous machinery or drive a vehicle? Sometimes carbamazepine causes sedation or impairs co-ordination, but these are usually temporary side effects.

Of special note to women : are you pregnant? Carbamazepine may cause some birth defects.

Tests: Before starting carbamazepine certain blood tests are necessary to ensure its safe to use and to provide a base line assessment of the functioning of body systems affected by carbamazepine. Blood tests to evaluate liver function are important because carbamazepine is broken up in the liver and also because carbamazepine can cause changes in liver function. A blood test of thyroid function is also important since an overactive or underactive thyroid gland may cause psychiatric symptoms that resemble mania or depression. Blood testing is also needed to determine counts of red and white blood cells and platelets.

How should carbamazepine be taken? carbamazepine is usually taken in divided doses over the course of the day usually 3 or 4 times daily. To minimise side effects most doctors will gradually increase the dose until the desired effect is achieved. Later the dose may again be adjusted with the goal of finding the 'minimal effective dose' i.e. the least amount of drug needed to obtain the desired side effect. Many people prefer to take their medication with meals, which not only help them remember to take it, but also helps to avoid nausea that may occur if it is taken on an empty stomach.

How often is carbamazepine blood test needed? Blood tests are needed more often when carbamazepine therapy is started or when dosage is adjusted than when treatment has been stabilised. When first starting carbamazepine, blood levels are determined rather frequently once a week or every other week. Once blood levels have stabilised, a level may be needed only once a month or even less as determined by the doctor.

A doctor may also request a blood level check at any time a patient shows signs that the amount of carbamazepine in the blood may be too low or too high i.e.

1. a return of signs of the manic depressive disorder indicating that the carbamazepine level is too low OR
2. an increase in side effects indicating that the carbamazepine level is too high.

Usually blood levels are determined in blood drawn 8 - 12 hours after the patients last dose.

How can someone tell if carbamazepine is working properly? Carbamazepine is working properly if it effectively controls mood swings while producing few, if any side effects.

How rapidly does carbamazepine work? Carbamazepine is seldom effective immediately. It may take one to several weeks before improvement begins and further improvement may occur gradually over time.

How does carbamazepine work? Chemical imbalances in certain brain cells responsible for emotions and behaviour are felt to be at the root of manic depressive disorder. Experts think that carbamazepine may act to correct these imbalances and, therefore, stabilise mood.

If someone on carbamazepine has another manic or depressive episode, does that mean carbamazepine isn't working? Not necessarily. Ideally carbamazepine helps prevent further mood swings, but a partial response to carbamazepine is not uncommon. Recurrent episodes are usually less severe, less frequent and may disappear completely with continued carbamazepine use. Although not everyone responds to carbamazepine, many people do eventually so it is essential that treatment is not stopped before the drug has an adequate chance to work. In some people neither lithium nor carbarnazepine alone may be effective in controlling mood swings. Sometimes mood swings can be controlled with a combination of lithium and carbamazepine even though neither was fully effective when used alone.

Are there any side effects?

Like all medication carbamazepine may cause side effects. It is important to recognise these side effects and know how to manage them

Last revised: February 29, 2000