Modafinil — the interactions razumna discloses

A short reference on the interactions razumna considers important enough to disclose. The list is not exhaustive. For anything not listed, talk to a qualified physician.

Hormonal contraceptives, the critical disclosure

Modafinil is a CYP3A4 inducer. It accelerates the hepatic metabolism of steroid hormones in hormonal contraceptives, reducing their blood levels and reducing contraceptive effectiveness. The effect persists for approximately one month after the last dose. This interaction appears in the FDA label and razumna treats it as the single most important interaction to surface.

Anyone relying on hormonal contraception who takes modafinil should use a non-hormonal backup method during use and for at least one month after the final dose.

Caffeine

Caffeine and modafinil are both alertness-promoting compounds acting through different pathways. They are additive in effect and additive in side-effect ceiling, particularly anxiety. Users who run anxious on caffeine alone often find that the addition of modafinil pushes them past tolerance.

Alcohol

Alcohol and modafinil work in opposite directions, alcohol is a depressant, modafinil is a wakefulness agent. Combining the two does not eliminate alcohol’s impairment. Decisions made under the combination remain impaired, even when the user feels alert. The combination is not a recommended use case.

Prescription medications

Modafinil interacts with several classes of prescription medication, particularly those metabolised through the CYP3A4 enzyme pathway. Anyone on a prescription regimen should consult their prescribing physician before adding modafinil. This is not a setting for self-directed evaluation.

Food and grapefruit

Food slightly delays the peak plasma concentration of modafinil but does not change total exposure. The drug can be taken with or without food. Grapefruit weakly inhibits CYP3A4 and can mildly slow modafinil clearance at heavy intake; the effect is not clinically meaningful at normal dietary levels.

Other central nervous system stimulants

Combining modafinil with other prescription stimulants is not advisable without clinical supervision. The side-effect profiles stack; the cardiovascular and psychiatric risk profiles stack. Anyone whose clinical situation involves multiple alertness agents should be doing so under physician oversight.

When in doubt

Razumna is not a clinical service. For any interaction question not covered here, and particularly for any combination involving prescription medication, supplements taken for therapeutic effect, or conditions under active clinical management, the right answer is a conversation with a qualified physician.

Related

For dosing protocols, see modafinil dosage. For the side-effect profile, see modafinil side effects.