Does Caffeine Affect Dilantin?

The Food and Drug Administration lists caffeine as both a food additive and a drug. Produced by more than 60 plants, caffeine's main effect is stimulation of the central nervous system. Dilantin is a brand name for phenytoin, a prescription drug used to treat epilepsy. Both compounds can cause serious side effects. Some patients with epilepsy may need to limit their caffeine intake.

Caffeine

According to the FDA, 80 percent of American adults consume some form of caffeine every day. Caffeine is found in coffee, tea, cola, energy drinks and chocolate. The average daily intake is 200 milligrams, which is the amount contained in two cups of coffee or four cans of soda. Several prescription drugs and many over-the-counter medications and supplements contain caffeine, including pain relievers, cold medicines and diet aids. In moderate doses, caffeine increases alertness and improves the effectiveness of pain medications. At higher doses, it causes shakiness, insomnia, heart palpitations and high blood pressure.

Dilantin

Doctors use Dilantin to control certain types of seizures in patients with epilepsy. A seizure occurs when the brain's electrical system malfunctions. Head injuries and brain disorders may cause epilepsy, although in many patients the cause is unknown. Dilantin may be taken alone or in combination with other anti-seizure drugs. Dosage forms include capsules, chewable tablets and liquids. Dilantin works best within a narrow blood level range. Alcohol and many medications increase or decrease blood levels of Dilantin. This can reduce Dilantin's ability to control seizures. Tell your doctor about all medications and supplements you are taking if you have epilepsy.

Interaction Between Caffeine and Dilantin

The database at Drugs.com does not list any interaction between caffeine and Dilantin. However, Dilantin increases the rate at which your body breaks down and eliminates caffeine. Faster elimination results in lower blood levels and reduces caffeine's effect on your system. Let your doctor know if you are taking both Dilantin and a medication containing caffeine. She may adjust the dose of the caffeine-containing drug, or prescribe a drug that does not interact with Dilantin.

Caffeine and Epilepsy

Caffeine may trigger seizures in some people, although clinical studies have not confirmed this. A prospective long-term study of caffeine's role in seizures was published in the February 2010 issue of Epilepsia. Researchers at Brigham and Women’s Hospital and Harvard Medical School found no association between caffeine intake and seizures in young women. Approximately half of the subjects consumed twice the average daily dose of caffeine. According to the authors, other studies suggest a link between very high doses of caffeine and seizures. If you have epilepsy, ask your doctor if you should avoid caffeine.