FDA Drug Safety Communication: Serious CNS reactions possible when Linezolid given with certain psychiatric medications

**Admin** Tue Aug 09, 2011 2:30 am

FDA Drug Safety Communication: Serious CNS reactions possible when Linezolid (Zyvox®) is given to patients taking certain psychiatric medications.

[07-26-2011]
The U.S. Food and Drug Administration (FDA) has received reports of serious central nervous system (CNS) reactions when the antibacterial drug Linezolid (marketed as Zyvox®) is given to patients taking psychiatric medications that work through the serotonin system of the brain (serotonergic psychiatric medications).

Mechanism:
Although the exact mechanism of this drug interaction is unknown, linezolid inhibits the action of monoamine oxidase A—an enzyme responsible for breaking down serotonin in the brain. It is believed that when linezolid is given to patients taking serotonergic psychiatric medications, high levels of serotonin can build up in the brain, causing toxicity. This is referred to as Serotonin Syndrome—signs and symptoms include mental changes (confusion, hyperactivity, memory problems), muscle twitching, excessive sweating, shivering or shaking, diarrhea, trouble with coordination, and/or fever.

Healthcare professionals and patients may not realize that linezolid has monoamine oxidase inhibitor (MAOI) properties.
Linezolid should generally not be given to patients taking serotonergic drugs.

Additional Information for Healthcare Professionals

- Linezolid (Zyvox®) can interact with serotonergic psychiatric medications and cause serious CNS toxicity.
- In emergency situations requiring life-threatening or urgent treatment with linezolid, the availability of alternative interventions should be considered and the benefit of linezolid treatment should be weighed against the risk of serotonin toxicity. If linezolid must be administered to a patient receiving a serotonergic drug, the serotonergic drug must be immediately stopped and the patient should be closely monitored for emergent symptoms of CNS toxicity for two weeks (five weeks if fluoxetine [Prozac] was taken), or until 24 hours after the last dose of linezolid, whichever comes first.
- In non-emergency situations when non-urgent treatment with linezolid is contemplated and planned, the serotonergic psychiatric medication should be stopped, to allow its activity in the brain to dissipate. Most serotonergic psychiatric drugs should be stopped at least 2 weeks in advance of linezolid treatment. Fluoxetine (Prozac), which has a longer half-life compared to similar drugs, should be stopped at least 5 weeks in advance.
- Treatment with the serotonergic psychiatric medication may be resumed 24 hours after the last dose of linezolid.
- Serotonergic psychiatric medications should not be started in a patient receiving linezolid. Wait until 24 hours after the last dose of linezolid before starting the antidepressant.
- Educate your patients to recognize the symptoms of serotonin toxicity or CNS toxicity and advise them to contact a healthcare professional immediately if they experience any symptoms while taking serotonergic psychiatric medications or linezolid.
- Report adverse events involving linezolid or serotonergic psychiatric medications to the FDA MedWatch program.

A list of the serotonergic psychiatric medications that can interact with Linezolid:

Selective Serotonin Reuptake Inhibitors (SSRIs)
Paroxetine
Fluvoxamine
Fluoxetine
Sertraline
Citalopram
Escitalopram

Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)

Venlafaxine
Desvenlafaxine
Duloxetine

Tricyclic Antidepressants (TCAs)

Amitriptyline
Desipramine
Clomipramine
Imipramine
Nortriptyline
Protriptyline
Doxepin
Trimipramine

Monoamine Oxidase Inhibitors (MAOIs)

Isocarboxazid
Phenelzine
Selegiline
Tranylcypromine

Other Psychiatric Medications

Amoxapine
Maprotiline
Nefazodone
Trazodone
Bupropion
Buspirone
Vilazodone
Mirtazapine

Source: FDA
FDA Drug Safety Communication: Serious CNS reactions possible when Linezolid given with certain psychiatric medications Linezo10

FDA Drug Safety Communication: Serious CNS reactions possible when Linezolid given with certain psychiatric medications Linezo10

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