Zoloft which is an antideprant that increases the sorotninlevel in your brain. Mianserin, is an older type of antidepressant that belongs to the tetracyclic family is a selective 5HT2 antagonist that also causes an increase of serotonin level in your brain. Research shows that increasing levels of serotonin in the brain treats the symptoms of depression.
However, too much serotonin may cause a condition called Serotonin Syndrome. The symptoms of the serotonin syndrome are: euphoria, drowsiness, sustained rapid eye movement, overreaction of the reflexes, rapid muscle contraction and relaxation in the ankle causing abnormal movements of the foot, clumsiness, restlessness, feeling drunk and dizzy, muscle contraction and relaxation in the jaw, sweating, intoxication, muscle twitching, rigidity, high body temperature, mental status changes, shivering, diarrhea, loss of consciousness and death.
The optimal treatment for the serotonin syndrome is discontinuation of the offending medication or medications, offer supportive measures, and wait for the symptoms to resolve. If the offending medication is discontinued, the condition will often resolve on its own within a 24 hour period.
Therefore it is recommended that Zoloft, Prozac, Paxil, Luvox, Serzone, etc. not be used concurrently with each other or any other serotonergic drugs.