Serotonin Syndrome

Q: All of the following are relatively contra-indicated in Serotonin Syndrome (SS) except?

A) Cyproheptadine
B) Propranolol
C) Bromocriptine
D) Dantrolene
E) Chlorpromazine



Answer: A

Out of all of the above, Cyproheptadine is established as an antidote for SS.  Cyproheptadine is a histamine-1 receptor antagonist as well as has anticholinergic activity. Benzodiazepines can also be used to control agitation.

Olanzapine is also recommended to counter SS but data is not convincing.

Chlorpromazine may increase hyperthermia. 

Interestingly in SS, monitoring of tachycardia is used to gauge the effectiveness of treatment. Propranolol can mask tachycardia. Also, it can induce prolong hypotension due to it's prolong half life.

 Bromocriptine is a serotonin agonist! - and should be avoided.

Dantrolene has no role in SS.


References:

1. Boyer EW, Shannon M. The serotonin syndrome. N Engl J Med 2005; 352:1112.

2. Graudins A, Stearman A, Chan B. Treatment of the serotonin syndrome with cyproheptadine. J Emerg Med 1998; 16:615. 

3. Gillman PK. The serotonin syndrome and its treatment. J Psychopharmacol 1999; 13:100. 

4. McDaniel WW. Serotonin syndrome: early management with cyproheptadine. Ann Pharmacother 2001; 35:870.