Can Lamictal reduce the efficiency of Nexplanon?

Question

Hello doctor,

Does Lamictal decrease Nexplanon’s efficacy? I had sexual intercourse a week ago for three days, and he pulled out. I have read online that lamictal increases Nexplanon’s efficacy by 20%. I am not sure if this is true or not. I am very worried that I could become pregnant because of this. I want to see if there is a possibility that I could be pregnant because Lamictal decreases Nexplanon’s effectiveness. My current medications are Lamictal, Gabapentin, and Zyprexa.

Please suggest.

Answer 1

Hello,

Welcome to icliniq.com.

I read your query and can understand your concern.

Lamictal (Lamotrigine) does not decrease the effectiveness of Nexplanon. Most research suggests that Nexplanon’s hormone (Etonogestrel) may lower Lamictal levels, rather than the other way around. Some sources claim that Lamictal might increase Nexplanon’s efficacy slightly, but there is no strong evidence that it significantly alters its effectiveness. The main concern with Nexplanon and drug interactions is enzyme-inducing medications like certain seizure medications (for example, Carbamazepine, Phenytoin, and Rifampin), which can reduce Nexplanon’s effectiveness. However, Lamictal is not an enzyme inducer. You have Nexplanon, which is over 99 percent effective. Your partner pulled out, which adds an extra layer of protection. Lamictal does not reduce Nexplanon’s effectiveness. The chance of pregnancy is extremely low. If you are still feeling anxious, you could take a pregnancy test about two weeks after intercourse for reassurance. Let me know if you have any other concerns.

I hope this helps.

Thank you and take care.