Hi, this is not serotonin syndrome as this syndrome is caused by over dosage of medicine or when one is taking
2 or more antidepressants of same class simultaneously. But you have already stopped the medicine.
In case of serotonin syndrome “Symptom onset is usually rapid, often occurring within minutes after
self-poisoning or a change in medication. Serotonin syndrome encompasses a wide range of clinical findings.
Mild symptoms may only consist of tachycardia, and shivering, diaphoresis (sweating commonly associated with
shock), mydriasis (dilated pupils), myoclonus (intermittent tremor or twitching), as well as overactive or
overresponsive reflexes. In addition moderate intoxication includes abnormalities such as hyperactive bowel
sounds, hypertension and hyperthermia; a temperature as high as 40 °C (104 °F) is common in moderate
intoxication. The overactive reflexes and clonus in moderate cases may be greater in the lower limbs than in
the upper limbs. Mental status changes include hypervigilance and agitation.
Severe symptoms include severe hypertension and tachycardia that may lead to shock. Severe case often have
agitated delirium as well as muscular rigidity and high muscular tension. Temperature may rise to above 41.1
°C (105.98 °F) in life-threatening cases. Other abnormalities include metabolic acidosis,
rhabdomyolysis, seizures, renal failure, and disseminated intravascular coagulation”. Taken from website
http://en.wikipedia.org/wiki/Serotonin_syndrome
Please consult doctor as this might be withdrawal effects of drug and please get drug optimization done.