Tegretol-XR is the brand name used for one form of extended-release carbamazepine available in the United States. Tegretol-XR was developed to provide more convenient dosing of carbamazepine and less fluctuation of blood levels. The Food and Drug Administration (FDA) approved it in 1996.

Forms
Tegretol-XR is manufactured in the United States by Novartis. It is available in tablet form, in three doses. (These descriptions apply to the U.S. versions.):

		100-mg (yellow) Tablets with an opening in the shell on one side. Imprinted T on one side and 100 mg on the other.
		200-mg (pink) Tablets with an opening in the shell on one side. Imprinted T on one side and 200 mg on the other.
		400-mg (brown) Tablets with an opening in the shell on one side. Imprinted T on one side and 400 mg on the other.

The contents of Tegretol-XR tablets are released through the small opening on one side. Fluid is absorbed through the shell, causing the contents to expand and slowly push out through the opening. The shell does not dissolve and may be seen in the feces. Tell patients that this is normal and does not mean that the medicine has not been absorbed.

In other countries, different extended-release forms of carbamazepine may be available. In the UK, for instance, Tegretol Retard is often used. Unlike Tegretol-XR, it uses coated pellets to deliver the medicine to the body over a long period. Tegretol Retard tablets can be divided for flexible dosing, but they should not be chewed or crushed.

How to take and store Tegretol-XR
Tegretol-XR tablets must be swallowed whole. They must not be chewed, divided, or crushed. Caution patients to examine each tablet before taking it, to ensure that its shell is not cracked or broken. Damaged Tegretol-XR tablets should not be used. If the shell is broken, the contents will be released too quickly. (The effect would be the same as taking a prompt-release form of carbamazepine.)

Tegretol-XR should be stored at controlled room temperature (below 86°F, 30°C).

Missed doses
Because Tegretol-XR is usually taken only twice daily, patients are less likely to miss doses than if they take Tegretol, which may require tid or qid dosing. Advise patients to take a forgotten dose immediately unless it is almost time for the next dose. In that case, they should either skip the forgotten dose (rather than taking a double dose) or make it up with the next 2 or 3 doses.

Patients who often forget doses may benefit from using a special pillbox or watch with an alarm.