The long metabolite is why this INN has its own washout
Serotonin syndrome is the reason: rigidity, fever, autonomic chaos, agitation toward delirium. The label cites fatal cases when fluoxetine met an MAOI or when an MAOI started too soon after fluoxetine.
Five weeks is the minimum after stopping. The text allows longer after chronic or high-dose use. Fourteen days is the minimum after an MAOI before 20 mg starts. Those numbers are not interchangeable.
A 'quick switch' because 20 mg felt activating in week one is how this calendar gets ignored. Read the activation sibling first.
Other SSRIs taught a two-week habit that fails this INN
Fourteen days after an MAOI before starting 20 mg is one direction. Five weeks after stopping fluoxetine before an MAOI is the other. They are not interchangeable.
Norfluoxetine can linger toward sixteen days of half-life. That is why the label allows longer after chronic or high-dose use.
A quick switch because week one felt activating is how the calendar gets ignored. Read the activation sibling first.
Pimozide is contraindicated. Thioridazine waits five weeks after Prozac too. Those are not MAOIs and still matter.
Linezolid and IV methylene blue sneak in as hospital drugs. Say fluoxetine even if the last 20 mg was last month.
Tricyclics need a temporary respect for leftover inhibition
The label says TCA dose may need reduction and plasma levels may need watching when fluoxetine is coadministered or recently stopped. That is CYP2D6 baggage, not serotonin-syndrome theatre.
A home leap from 20 mg to a full amitriptyline night is how people get unexpectedly sedated or anticholinergic.
Write the stop date on the TCA script request so nobody assumes a clean enzyme.
Five weeks is a number you can write on a calendar
Mark the last 20 mg day. Count thirty-five. That is the minimum before a psychiatric MAOI, with perhaps longer after chronic or high-dose use.
Do not restart leftover capsules in week three of the wait because mood dipped. That resets or overlaps the clock.
A new psychiatrist still needs the stop date. Bring the empty box.
Activation in week one is a different sibling. Do not hop to an MAOI because jitter felt like the wrong class.
Suspected serotonin syndrome - rigidity, fever, swinging vitals, delirium - is 144. Bring both packs.
A hospital sticker that says SSRI is not enough
Write fluoxetine and the last 20 mg date on the admission list, not 'an antidepressant'. Linezolid and methylene blue arrive as other teams' drugs.
A weekend wound clinic that starts linezolid will not read a Geneva markup. Carry the empty box or a photo of the label.
If you already swallowed both, do not take another 20 mg to even things out. Seek care. Serotonin-syndrome picture: 144.
Psychiatry MAOIs still need the thirty-five-day count from the last swallow, longer after chronic or high-dose use. Fourteen days is the other SSRI habit.
Weekly 90 mg is a different product. Say which one you stopped. This domain locked daily 20 mg uses.
Parent fluoxetine plan for the lock. Activation sibling if week-one jitter is why someone wants a fast switch. This page is only the calendar.
What to treat as an emergency rather than a bad mood day
High fever, stiff muscles, fast or swinging vitals, and a mental-state change that looks like delirium: emergency care. Bring both bottles.
Mild tremor and diarrhoea after a missed gap still deserve a same-day call. Do not add a second serotonergic from a drawer.
Tryptophan supplements and some migraine triptans belong on the list you carry. The parent plan has a wider interaction set.
Calendar rules under the 20 mg lock
- 5 weeks fluoxetine → MAOI
- 14 days MAOI → fluoxetine 20 mg
- Name linezolid and methylene blue on every admission
- Do not restart leftover 20 mg during an MAOI start
Most SSRI-to-SSRI hops are not this five-week story
Switching 20 mg fluoxetine to sertraline or escitalopram is a different prescriber plan. Residual fluoxetine still inhibits CYP2D6 for a while and can raise some tricyclic levels. That is not an MAOI washout.
Do not apply five weeks to every switch or people stay untreated. Do apply five weeks when the next drug is an MAOI.
The activation markup is about staying on 20 mg through week one. This draft is about leaving 20 mg toward a forbidden pair.
Two other named stops that are not MAOIs
Pimozide is contraindicated with fluoxetine over QT and interaction risk. Thioridazine is contraindicated; do not start thioridazine within five weeks after stopping Prozac.
Those five weeks rhyme with the MAOI wait because the metabolite lingers. They are still a different mechanism story.
A hospital 'something for psychosis' cup needs a name. 'An old antipsychotic' is not a med rec.
Say fluoxetine even if the last 20 mg was three weeks ago
The metabolite is still the point. A surgical methylene-blue plan needs the word fluoxetine out loud.
Linezolid for a wound is the other sneak. Hold the pride about 'I stopped last month'.
Bring the empty 20 mg box. Dates beat memory.
A new psychiatrist who did not write the 20 mg still needs the stop date before an MAOI.
Psychiatric MAOIs and the ones that sneak in as antibiotics
Phenelzine, tranylcypromine, isocarboxazid, and similar psychiatric MAOIs are the classic pair. Selegiline and rasagiline stories still need a specialist, not a markup exception at 20 mg.
Linezolid is an antibiotic with MAOI activity. Do not start Prozac 20 mg on a patient receiving linezolid. If someone on fluoxetine needs linezolid, that is an inpatient risk conversation, not a home overlap.
Intravenous methylene blue is the other named stop. A surgical or urology list should hear the word fluoxetine out loud.
| Direction | Minimum labelled gap | Do not do |
|---|---|---|
| Stop fluoxetine → start psychiatric MAOI | 5 weeks (maybe longer) | Count 14 days like other SSRIs |
| Stop MAOI → start fluoxetine 20 mg | 14 days | Start 20 mg 'because mood crashed' |
| Linezolid or IV methylene blue | Do not combine | Hide the 20 mg bottle on admission |
Travel, samples, and the leftover 20 mg blister
Patients stop 20 mg, feel a dip at week three, and still have capsules. Restarting without telling the psychiatrist who just wrote an MAOI is the classic error.
Cross-border samples and 'my sister's leftover Prozac' skip the start date. Write the last 20 mg day on paper.
Weekly 90 mg capsules change the math. Tell the clinician which product you were on. This desk locked daily 20 mg, not the weekly NDC.
Sisters leftover 20 mg is how calendars die
A shared bathroom bag with old Prozac next to a new MAOI is the overlap this draft exists to stop. Write the last swallow date on paper and throw or return leftovers if the clinician agrees.
Cross-border samples skip the start date. Ask when the first and last 20 mg happened.
Weekly 90 mg changes the math. Say which product you were on. This domain locked daily 20 mg.
Five weeks is thirty-five days, not about a month after the jitter faded.
St John's wort is not a gentle gap-filler
Serotonergic herbs plus leftover fluoxetine are a clinic question, not a health-shop yes.
Tryptophan powders sit in the same messy pile. Name them.
The five-week MAOI wait does not become two weeks because a tea claimed to 'clear serotonin'.
Write the last 20 mg date before anyone says MAOI
Parent Prozac 20 mg uses. Activation sibling for week one. This draft is only the long tail so the lock is not treated like a short SSRI when the next bottle is an MAOI.
Suspected serotonin syndrome: 144. Bring both packs.
Sources
- FDA Prozac PI - 5 weeks after stopping before psychiatric MAOI; 14 days after MAOI before start; linezolid; methylene blue.
- Contraindications - pimozide; thioridazine (and 5 weeks before thioridazine).
- PK - fluoxetine and norfluoxetine long half-lives.
Checked against the current label and reviewed by Dr. Amélie Laurent. See Survey, Draft, Peer-check, Stamp.