Serotonin is a naturally occurring brain chemical that helps brain and nerve cells communicate. But when too much builds up, it can cause toxicity and even death. This usually occurs when people take two or more medications that increase the level of serotonin in the brain. This drug reaction, called serotonin syndrome, can be treated if caught in time.
Causes
Serotonin levels are affected by several different classes of drugs including migraine medications called triptans, antidepressants such as selective serotonin reuptake inhibitors (SSRIs), selective serotonin/norepinephrine reuptake inhibitors (SSNRIs) and monoamine oxidase inhibitors (MAOIs), along with the painkiller meperidine and the cough medicine dextromethorphan. Non-prescription drugs like ecstasy and LSD as well as supplements like St. John's Wort have also been associated with serotonin syndrome.
The most common cause of the problem is combining two medications that affect serotonin levels. But it can also be caused by taking too much of a single medication, particularly when someone deliberately overdoses, according to the Mayo Clinic. The problem is most likely to occur when starting a new medication or increasing an old one, according to MedlinePlus.
Symptoms
Symptoms include agitation, diarrhea, racing heart, hallucinations, fever, lack of coordination, nausea and vomiting, overactive reflexes and swings in blood pressure. Other symptoms include heavy and unexplained sweating, confusion, muscle spasms, dilated pupils, shivering, goosebumps, headache and tremor. In the most severe cases, serotonin syndrome can cause seizures, irregular heartbeat and loss of consciousness.
A person may not have all of these symptoms, but if serotonin syndrome is suspected, the person should seek immediate medical care, according to MedlinePlus.
Prevention
Serotonin syndrome is preventable. A patient should tell all his doctors about the medications he is taking, including any supplements, over-the-counter medications and illegal drugs.
Also, the doctor should monitor the patient closely whenever he prescribes a new drug or increases the dose of an old drug that affects serotonin levels. This is particularly true of patients taking triptans or antidepressants.
Patients should talk to their doctors about their risks and what to look out for so that they can seek medical care quickly if they have a problem.
Treatment
Serotonin syndrome is often treated in a hospital. The doctor will likely take the patient off the medicines that caused the problem and may prescribe a drug to block serotonin. The patient should not stop taking medications on her own without her doctor's supervision as that can cause other complications.
The patient may also be given fluids and benzodiazepines to decrease agitation and other symptoms. In the most severe cases, medicines that paralyze the muscles to prevent tissue damage may be given or a breathing tube may be needed.
Outlook
With proper treatment, serotonin syndrome usually clears up in about a day.
However, severe spasms can cause serious muscle damage. This can produce toxins that can also damage the kidneys.
