All you need to know about modafinil and the Pill

There has been a lot of concern about the effectiveness of the birth control pill and modafinil. It seems that some GPs are unsure about the effects and are giving out conflicting information, not only to what people may have read but what they are told by specialists.

Narcolepsy UK decided to get a definitive answer and contacted not only the manufacturers but also The Faculty of Sexual & Reproductive Healthcare (part of the Royal College of Obstetricians and Gynaecologists).

The answers are clear. Modafinil may reduce the effectiveness of several types of hormonal contraceptives and not just oestrogen-based ones.

Modafinil affects certain enzymes that break down drugs and thereby reduce the effectiveness of some contraceptive medications. A study published in 2002 in which women on the pill received modafinil 200 mg a day for 7 days, and then 400 mg a day for 21 days showed a decrease in the maximum blood concentration of ethinylestradiol, a synthetic version of the female hormone oestrogen. Although there is no scientific data, it is highly likely that modafinil will reduce the effectiveness of contraceptives containing other synthetic oestrogens, for example mestranol and estradiol.

Synthetic oestrogens such as these are used in combined oral contraceptives, the contraceptive patch Evra and the vaginal ring NuvaRing. The blood concentrations of synthetic oestrogen is reduced when taken with modafinil and there may thus be an increased risk of pregnancy with these types of contraceptives.

Another group of hormonal contraceptives are the progestogen-only pills or POPs. As the name implies these only contain a progestogen – a synthetic version of the naturally occurring hormone progesterone. Traditionally, these have not provided the same degree of efficacy as oestrogen containing contraceptives. However, these synthetic hormones are also broken down in the body in a similar manner to synthetic oestrogens and thus their contraceptive efficacy may be reduced when taken at the same time as modafinil.

The same situation applies to progestogen-containing implants.

If you are not sure what type of contraceptive you are using check the Patient Information Leaflet which would have been packed with the product.

If you use modafinil and use any of the above types of contraceptive products, it is important that you speak to your usual clinic or GP. With combined oral contraceptives it is possible to overcome the effect of modafinil by increasing their dose and using a shorter pill-free period. If this is not appropriate or for those taking other hormonal contraceptives there are alternatives methods of contraception available such as barrier methods or an intra-uterine device (IUD). In addition, some progestogen-only products given by injection into the muscles are not affected by other medications like modafinil and thus may be used by narcoleptic women taking modafinil.

Finally, emergency contraception (the ‘morning after pill’). These product contain hormones with which modafinil may interact. Maximal efficacy of emergency contraception may be reduced in women who are taking modafinil.

So there you have it; if you are on modafinil it could cause problems with your birth control medication if you use one of the following:

• Combined pill
• Oestrogen patch
• Oestrogen vaginal ring
• Progestogen only pill
• Progestogen implant.
• Emergency contraception

If you want protection against pregnancy and don’t want to use either a barrier method or non-medicated IUD your alternatives are increasing the dose of oestrogen in a combined pill, injections of some progestogens or possibly a medicated IUD such as Mirena.