Serotonin syndrome results from certain drugs interacting and producing an excess of serotonin. The National Institutes of Health (NIH) states that combining triptans, a migraine medication, with antidepressants, such as selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs), can cause excess serotonin. Certain medications alone, like monoamine oxidase inhibitors (MAOIs), another antidepressant; meperidine, a pain killer; and dextromethorphan, a cough medication, can increase serotonin to unsafe levels. The syndrome begins when the person starts taking a medication or increases the dosage, with symptoms starting within minutes or hours. If serotonin syndrome is left untreated, the patient can die.
Changes in Mobility
The NIH notes that for a patient to be diagnosed with serotonin syndrome, she must have at least three symptoms, including changes in her mobility. The patient can have changes in mobility from too much serotonin. Motor symptoms include overactive reflexes and twitching muscles. The patient may also have a loss of coordination, making it difficult for the patient to move around. Other mobility symptoms include tremors and uncoordinated movements, a condition called ataxia.
Cognitive and Behavioral Changes
Excess serotonin can also affect cognition and behavior. The patient can become confused quickly; he may not know what is going on or where he is. Agitation and restlessness can also occur. Another possible symptom is hypomania, in which the patient has a slight elevation in mood. Some serotonin syndrome patients may have hallucinations, in which they see, hear, touch, smell or taste something that does not exist; even if patients are told that a visual hallucination, for example, is not real, they will insist the object is there.
Other Effects
Patients can feel ill at the onset of the serotonin syndrome symptoms. These symptoms include nausea, diarrhea and vomiting. The patients may also have severe headaches, coupled with heavy sweating, although some may experience goosebumps and shivering instead. Dilated pupils can also occur. Other effects from excess serotonin are a fast heartbeat, increased body temperature and rapid changes in blood pressure. These signs will appear quickly and without an apparent cause.
