Any time a doctor suggests a new prescription, be sure to talk about what other medicines, supplements, herbs, and vitamins are already being taken. Sometimes one kind of medicine changes the way another kind of medicine works in the body. If two kinds of medicine affect each other, the doctor may prescribe something else or change the amount to be taken.

How does Felbatol affect other medicines?
Felbatol makes birth control pills less effective, so the chances of becoming pregnant are greater. Women who use pills for birth control should talk to the doctor who prescribed them right away if they start taking Felbatol. The same is true for some other forms of birth control such as Depo-Provera or implants. Felbatol does not affect barrier types of birth control, like condoms, IUDs, and diaphragms.

Felbatol affects the way the body handles many other medicines. If combination therapy using Felbatol and another seizure medicine is begun, the dosage of the first medicine may need to be adjusted. Similarly, if a seizure medicine previously used in combination therapy is to be stopped, the dosage of the remaining medicine may need to be changed.

Felbatol may increase the level of these seizure medicines in the blood:

• Dilantin or Phenytek (phenytoin)
• carbamazepine-epoxide (the breakdown product of Tegretol, Tegretol XR and Carbatrol)
• phenobarbital
• Depakote and other valproate medicines (Depakene, valproic acid)

How do other medicines affect Felbatol?
Some other medicines may affect the level of Felbatol in the body, either raising it or lowering it. Make sure that the doctor is aware of all the medicines being used.

A few other seizure medicines may reduce the level of Felbatol in the blood:

• Dilantin or Phenytek (phenytoin)
• Tegretol, Tegretol XR, or Carbatrol (carbamazepine)
• phenobarbital

Depakote and other valproate medicines (Depakene, valproic acid) may increase the blood level of Felbatol.