Linerzolid (Zyvox)抗菌藥不能和serotonergics (抗憂鬱劑)一起使用!!

Serotonergics 抗憂鬱劑 和 Zyvox (對MRSA之類革蘭陽性菌有效，可以靜脈注射 或口服) 或 methylene blue (用於氰中毒或methemoglobinemia) 一起使用，會引起 serotonin syndrome (意識及記憶混亂、過動、肌肉顫抖不協調、過度流汗、腹瀉、發燒等)，因為Zyvox及methylene blue會抑制 monoamine oxidase A 酵素分解serotonin的作用，而使 serotonin囤積過多。

 

FDA Updates Warnings on Methylene Blue,
Linezolid, and Serotonergics

Robert Lowes

Posted: 10/21/2011

October 21, 2011 — The US Food and Drug Administration (FDA)
has fine-tuned a warning issued in July to avoid prescribing either methylene
blue or linezolid (Zyvox,
Pfizer) in combination with serotonergic agents because of the potential to
cause serotonin syndrome.

Today, the FDA announced that the risk for this harmful
interaction appears to be confined, in general, to 2 specific types of
serotonergic drugs: selective serotonin reuptake inhibitors and serotonin-norepinephrine
reuptake inhibitors.

Methylene blue is a dye used in diagnostic procedures and in
the treatment of conditions ranging from 、cyanide poisoning to methemoglobinemia. Linezolid is an antibacterial agent.
Both drugs inhibit the action of
monoamine oxidase A, an enzyme that breaks down serotonin. This allows the
levels of the neurotransmitter to rise.

When serotonin builds up to excessive levels in patients
taking serotonergic agents, the result can be serotonin syndrome. Its signs and symptoms include confusion, hyperactivity, memory problems, and
other mental changes; muscle twitching, excessive sweating, shivering, or
shaking; diarrhea; trouble with coordination; and fever.

In July, the FDA announced that its Adverse Event Reporting
System database had received reports of cases of serotonin syndrome in patients
taking serotonergic drugs together with linezolid or methylene blue. In a few
cases involving linezolid, the patient died.

In 2 separate but similarly worded announcements issued
today regarding linezolid and methylene blue, the FDA retreated from the earlier blanket
warning about serotonergics.
The agency stated that not all such agents "have an equal capacity to
cause serontonin syndrome" in combination with the 2 other drugs. Most
Adverse Event Reporting System reports of serontonin syndrome involving
linezolid, the FDA stated, occurred in patients taking either a selective
serotonin reuptake inhibitor or a serotonin-norepinephrine reuptake inhibitor.

Likewise, the cases involving methylene blue happened with
patients receiving these same drugs as well as clomipramine, a tricyclic
antidepressant. The agency noted that most of these patients had received
methylene blue intravenously in the course of parathyroid surgery.

The FDA stated that it is not clear whether the combination
of either linezolid or methylene blue with psychiatric drugs of lesser degrees
of serotonergic activity poses "a comparable risk." Such drugs with
an unclear risk consist of most
tricyclic antidepressants, monoamine oxidase inhibitors, and several others:
amoxapine, maprotiline, nefazodone, trazodone, bupropion, buspirone, and
mirtazapine.

In addition, the agency said that because methylene blue is
an unapproved drug with little data about its use in various settings, it does
not know whether administering it orally or by injection, as opposed to
intravenously, to patients receiving a serotonergic runs the risk for serotonin
syndrome. The same uncertainty applies to intravenous doses of methylene blue
lower than 1 mg/kg.

More information about the FDA announcements on linezolid and methylene blue is available on the agency's Web site.

To report adverse events related to methylene blue or
linezolid, contact MedWatch, the FDA's Safety Information and Adverse Event
Reporting System, by telephone at 1-800-FDA-1088, by fax at 1-800-FDA-0178,
online at http://www.fda.gov/Safety/MedWatch/default.htm, or by mail to
MedWatch, FDA, 5600 Fishers Lane, Rockville, Maryland 20852-9787.

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