Cyclobenzaprine and Olanzapine and fluoxetine interaction
Cyclobenzaprine and Olanzapine and fluoxetine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Cyclobenzaprine (TONMYA) label · effective 2026-08-14
Hyperpyretic crisis seizures and deaths have occurred in patients who received cyclobenzaprine (or structurally similar tricyclic antidepressants) concomitantly with MAO inhibitors drugs.
Immediately discontinue concomitant treatment with TONMYA and a serotonergic agent if serotonin syndrome symptoms occur and initiate supportive symptomatic treatment.
Serotonin Syndrome The development of a potentially life-threatening serotonin syndrome has been reported with cyclobenzaprine when used in combination with other drugs, such as selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), tramadol, bupropion, meperidine, verapamil, or…
Treatment with TONMYA and any concomitant serotonergic agents should be discontinued immediately if serotonin syndrome symptoms occur and supportive symptomatic treatment should be initiated.
Based on its structural similarity to TCAs, concomitant use of TONMYA with: MAO inhibitors may be life-threatening [see Contraindications (4) ] , Alcohol, barbiturates, and other CNS depressants may increase the risk of adverse reactions associated with these drugs, Tramadol may increase the seizure risk, Guanethidine or other similar acting drugs may block the…
From the Olanzapine and fluoxetine label · effective 2026-03-31
If concomitant use of olanzapine and fluoxetine capsules with other serotonergic drugs is clinically warranted, patients should be made aware of a potential increased risk for serotonin syndrome, particularly during treatment initiation and dose increases ( 5.6 )
If concomitant use of olanzapine and fluoxetine capsules with other serotonergic drugs is clinically warranted, inform patients of the increased risk for serotonin syndrome and monitor for symptoms.
Anticholinergic (antimuscarinic) Effects : Use with caution with other anticholinergic drugs and in patients with urinary retention, prostatic hypertrophy, constipation, history of paralytic ileus or related conditions ( 5.21 )
The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, meperidine, methadone, tryptophan, buspirone, amphetamines, and St.
Serotonin Syndrome : Serotonin syndrome has been reported with SSRIs and SNRIs, including olanzapine and fluoxetine capsules, both when taken alone, but especially when co-administered with other serotonergic agents.
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.