Combining Lamictal with Birth Control Pills
Well, well . . . you learn something everyday . . .
I had a question posed to me about whether there are interactions between Lamictal and birth control pills. Lamictal, as you may know, is the only medication approved by the FDA for use in Bipolar Depression. It is a great medicine and is widely used because of how well it works and how well it is tolerated. Many of the women who take it are of child-bearing age and many of those use hormonal birth control methods. It is important that birth control pills, when taken, are effective–women are counting on them to work. This is especially true when taking medications for psychiatric issues so that you avoid exposing the baby to psychiatric medicine unnecessarily. So, the question was a good one . . . and I was not sure of the answer at first. So . . . a little bit of research was in order!
While there are no absolutes in this business, it does seem that there is no clinically significant change in birth control pill blood levels and effectiveness when combined with Lamictal. The studies are limited, of course, but this is certainly encouraging. In the studies that were done, the women who were taking the combination did not show any clinical or hormonal signs of ovulation (supression of ovulation is the point of birth control pills). There is, however, a very slight effect of birth control pills on Lamictal concentrations (this is news to me!). Co-administration of Lamictal with birth control pills will result in slightly lower blood levels of Lamictal. During the one week placebo pill period of birth control pills, blood levels of Lamictal will actually go up. Slightly. There can be some potential clinical relevance to this. If you increase the dose of Lamictal at the same time that the patient is entering the blank-pill section of her birth control pills, she will be receiving a larger increase in the Lamictal than was intended. Since the most concerning side effect of the Lamictal (rash) is correlated with giving too much too fast, it may be prudent to avoid Lamictal increases during that last week of the pills.
You learn something every day!
–Dan Hartman, MD
