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Modafinil 100 mg still moves CYP3A4 substrates

Last reviewed · 7 min read · Updated

Modafinil induces CYP3A4/5 enough to lower steroidal contraceptives, cyclosporine, midazolam, and triazolam. Backup contraception runs through treatment and one month after the last tablet.

A 100 mg lock does not create an exception. Inhibitors and inducers of CYP3A move modafinil the other way.

Dr. Elise Moreau

Peer-passed by Dr. Elise Moreau, MD - Clinical pharmacology, Bordeaux. Gather, ink, peer-pass, bind.

01 The month after the last tablet is the easy one to miss

People stop Provigil for a holiday and keep the same pill pack. The insert's contraceptive line includes one month after discontinuation. Write a calendar reminder on the last 100 mg day. The wake margin will not remind you. This ink will.

Implants, rings, and hormonal IUDs still need that conversation. Barrier methods do not. Emergency contraception after a lapse is a clinic talk, not a second 100 mg.

The leaf has the shift clock. This file is enzymes.

CYP ink beside a Provigil 100 mg pack

02 What not to change without both desks

Do not raise cyclosporine yourself. Do not raise modafinil yourself to chase an old wake. Do not drop the backup pill because you feel fine.

If you switch from 100 mg to 200 mg, induction is not a reason to drop backup. The counseling line does not fade at 100.

Jet lag without an SWD diagnosis is not a reason to start 100 mg and scramble a contraceptive plan.

Copper IUDs do not need the steroidal backup speech. Hormonal devices still get the question. This margin will not parse every device by email.

Elise kept the one-month clause. Mail us if we dropped it.

03 How to reset the month-after clock when 100 mg stops and starts again

Write the last 100 mg date. Add one month. That is the backup end if you stop. If you restart, the month-after clock resets when you stop again.

The insert does not give a 100 mg exception. Implants, rings, and hormonal IUDs still need the conversation. Barrier methods do not.

Emergency contraception after a lapse is a clinic talk, not a second 100 mg.

Night workers forget this because the shift talk ate the visit. Put the reminder on the same slip as the pre-shift hour. The leaf repeats the line so it cannot hide.

A holiday stop of Provigil with the same ethinyl-estradiol pack is the easy miss. Keep backup through the month after.

04 Cyclosporine, midazolam, triazolam: levels can fall

Transplant teams need the start date. A "just 100 mg" start without a level plan is how rejection stories get a footnote. Do not make up a low cyclosporine level from an old bottle.

Sleep tablets that are CYP3A substrates can fail or shorten. That is a reason to say modafinil on the anesthesia list, not a reason to double midazolam at home.

Weak induction in vitro became a labeled counseling line because the substrates matter. Do not wave it off as theoretical because your tablet is 100 mg.

Schedule IV still applies. This is not a reason to share tablets.
PairDirection
Modafinil + ethinyl estradiolContraceptive effect may fall; backup + 1 month after
Modafinil + cyclosporineSubstrate may fall; team adjusts
Ketoconazole-type + modafinilModafinil may rise
Carbamazepine or rifampin + modafinilModafinil may fall

05 Cyclosporine, midazolam, and the anesthesia list

Transplant teams need the start date. Do not make up a low trough from an old bottle. Do not stop modafinil silently the night before a level unless they asked.

Sleep tablets that are CYP3A substrates can shorten. Say modafinil on the anesthesia list. Do not double midazolam at home because the first dose "felt weak."

Ketoconazole-type inhibitors can raise modafinil. Carbamazepine and rifampin can drop it. A dead tablet after rifampin is not a 02:00 redose.

St John's wort belongs on the list if it is in the cupboard.

Schedule IV still applies. This is not a reason to share tablets.

06 What not to change without both desks

Do not raise cyclosporine yourself. Do not raise modafinil yourself to chase an old wake. Do not drop the backup pill because you feel fine.

A holiday stop of Provigil with the same ethinyl-estradiol pack is the easy miss. Keep backup through the month after.

If you switch from 100 mg to 200 mg, induction is not a reason to drop backup. The counseling line does not fade at 100.

Elise kept the one-month clause. Mail us if we dropped it.

Jet lag without an SWD diagnosis is not a reason to start 100 mg and scramble a contraceptive plan.

07 Transplant levels and an anesthesia list

Cyclosporine troughs can fall when an inducer starts and rise when it leaves. Transplant teams need dates. Do not restart 100 mg to "bring a level down" and do not skip cyclosporine on your own.

Sleep tablets that are CYP3A substrates can shorten. Say modafinil on the anesthesia list. Do not double midazolam at home because the first dose felt weak.

Ketoconazole-type inhibitors can raise modafinil. Carbamazepine and rifampin can drop it. A dead tablet after rifampin is not a 02:00 redose. See the wake margin before you invent a second swallow.

St John's wort belongs on the list if it is in the cupboard.

Schedule IV still applies. This is not a reason to share tablets.

08 The other direction: your 100 mg may not be 100 mg in plasma

Strong inducers can leave a night worker wondering why the tablet "died." The answer may be carbamazepine, not a need for a 02:00 redose. Strong inhibitors can leave them wired into the day sleep.

Bring the full list. Include St John's wort if that is in the cupboard. Elise will not reconcile a spreadsheet by email.

09 How to put backup contraception on a real calendar

Write the last 100 mg date. Add one month. That is the backup end if you stop. If you restart, the month-after clock resets when you stop again.

The insert does not give a 100 mg exception. Implants, rings, and hormonal IUDs still need the conversation. Barrier methods do not.

Emergency contraception after a lapse is a clinic talk, not a second 100 mg.

Night workers forget this because the shift talk ate the visit. Put the reminder on the same slip as the pre-shift hour.

The leaf repeats the line so it cannot hide.

10 Start date on paper, backup on the calendar

Keep the last 100 mg date next to the backup method. Reviewed 21 August 2026, Bordeaux.

Write the last 100 mg date and add one month if you use steroidal contraception. Restarting resets that clock when you stop again. The insert does not give a 100 mg exception. Night workers should put this on the same slip as the pre-shift hour.

Cyclosporine levels can fall when the inducer starts and rise when it leaves. Anesthesia lists should name modafinil. Rifampin can kill a wake tablet; that is not a lunch redose. St John's wort belongs on the list if it is in the cupboard.

The leaf locks 100 mg. The wake margin is the hour file. Mail [email protected] if we dropped the one-month clause.

Twenty days after the last 100 mg is not a month. Keep backup through one month if you use a steroidal method. Do not start 100 mg the morning of a wedding to enjoy the day. That resets the clock when you stop again and is not a labeled use. Copper IUDs skip the steroidal speech. Hormonal devices still get the question.

A weak midazolam night beside 100 mg is a reason to name both drugs, not a reason to double the sleeper at home. Do not add a second 100 mg to push through insomnia. Transplant desks still need the stop date when a trough rises after the inducer leaves. Do not restart 100 mg to pull a level down.

Jet lag without an SWD diagnosis is not a reason to start 100 mg and scramble a contraceptive plan. If you switch from 100 mg to 200 mg, the counseling line does not fade. Backup stays. Elise kept the one-month clause on purpose.

Emergency contraception after a lapse is a clinic talk, not a second 100 mg. Night workers forget the backup sentence because the shift talk ate the visit. Put the reminder on the same slip as the pre-shift hour. St John's wort belongs on the list if it is in the cupboard. Do not raise cyclosporine yourself.

A holiday stop of Provigil with the same ethinyl-estradiol pack is the easy miss. Keep backup through the month after the last tablet. If you later switch to a hormonal method from copper, the one-month clause returns. Elise kept that clause so the night-shift visit cannot bury it.

Transplant troughs can rise when the inducer leaves. Bring them the stop date. Do not skip a cyclosporine dose on your own to chase an old number. Do not restart 100 mg to pull a level down. The same date starts the contraceptive month-after clock if you use a steroidal method.

Sleep tablets that are CYP3A substrates can shorten. Say modafinil on the anesthesia list. Do not double midazolam at home because the first dose felt weak. Ketoconazole-type inhibitors can raise modafinil. A wired night after an azole is a call, not a second 100 mg.

Do not drop the backup pill because you feel fine on 100 mg. The insert did not write a 100 mg exception for night workers either. Write the date.

Sources

  1. DailyMed Provigil section 7: CYP3A4/5 substrates; contraceptive backup through 1 month after stopping.
  2. Reviewed 21 August 2026 by Dr. Elise Moreau.

Checked against the current label and reviewed by Dr. Elise Moreau. See Gather, Ink, Peer-pass, Bind.

Desk thread

Desk thread on modafinil 100 mg and CYP. Not a level service.

Marine Dupuis I am on a combined pill and 100 mg. Is a condom only needed at the start?

Desk reply

The labeled counseling is backup during treatment and for one month after the last tablet, not only during week one. Enzyme induction is not a loading-dose rumor you wait out. If you stop the 100 mg on the 12th, keep backup into the next month. The leaf repeats the line so the shift talk does not bury it.

Aicha Diarra I stopped 100 mg 20 days ago. Wedding next week. Backup still?

Desk reply

Twenty days is not a month. Keep backup through one month after the last tablet if you use a steroidal method. Ask the person who placed an implant or hormonal IUD. Do not start 100 mg the morning of the wedding to "enjoy the day." That resets the clock when you stop again and is not a labeled use.

Omar Farouk Cyclosporine trough dropped after I started 100 mg. Take extra cyclosporine?

Desk reply

No. Call the transplant desk. They adjust. Extra capsules from an old bottle are how toxicity and rejection trade places. Bring the Provigil start date and the 100 mg strength. Do not stop modafinil silently the night before a level unless they asked.

Sigrid Holm I use a ring. Still backup for a month after the last 100 mg?

Desk reply

Ask the person who placed the ring. Steroidal methods still get the CYP3A conversation. This margin will not parse every device by email. Until they answer, do not assume 100 mg is too small to matter. The insert did not write that exception. Keep backup on the calendar.

Hanae Mori I use a hormonal IUD. Still backup for a month after 100 mg?

Desk reply

Ask the person who placed the IUD. Some hormone IUDs still get the CYP3A conversation; copper does not. This margin will not parse every device by email. Until they answer, do not assume 100 mg is too small to matter. The insert did not write that exception. The CYP ink exists so the shift talk does not bury the question.

Sigrid Dahl Rifampin for latent TB. Keep the 100 mg?

Desk reply

Rifampin induces CYP3A. Modafinil may fall. That is a two-desk problem: infection and sleep. This margin will not pick which drug yields. Do not double 100 mg on your own to chase the old wake. Ask before the next night shift.

Omar Fekih I start carbamazepine next week. Raise 100 mg now so the wake does not die?

Desk reply

Carbamazepine can drop modafinil. Raising 100 mg yourself is not the labeled answer. Call both desks. A dead tablet after an inducer starts is a reason to ask, not a reason to invent 200 mg at lunch. Backup contraception still applies. The one-month-after clock does not fade because an inducer entered the list.

Ibrahim Cisse Cyclosporine rose after I stopped 100 mg. Extra hold the Provigil?

Desk reply

Levels can rise when an inducer leaves. The transplant desk adjusts. Do not restart 100 mg to "bring cyclosporine down" and do not skip a dose of cyclosporine on your own. Bring them the stop date. That date also starts the contraceptive month-after clock if you use a steroidal method.

Hana Svoboda Copper IUD. Still write the month-after date?

Desk reply

Copper does not need the steroidal backup speech. Still write the last 100 mg date if a transplant or anesthesia desk will ask. The induction story is wider than contraception. If you later switch to a hormonal method, the one-month clause returns.

Marc Lefevre My midazolam felt weak the night I also took 100 mg. Double the sleeper?

Desk reply

No. Modafinil can shorten some CYP3A substrates. Doubling a sleeper at home is how a next-day drive gets dangerous. Say both names to the person who wrote the sleeper. Do not add a second 100 mg to "push through" the insomnia. That wrecks the next night.

Paolo Greco Who kept the one-month line?

Desk reply

Elise Moreau, 21 August 2026. Mail [email protected] if we dropped the month-after clause.