Serotonin Syndrome Causes, Symptoms, and Treatment

Serotonin Syndrome Causes, Symptoms, and Treatment Bipolar Disorder Treatment Medications Print Serotonin Syndrome Causes, Symptoms, and Treatment By Marcia Purse Marcia Purse is a mental health writer and bipolar disorder advocate who brings strong research skills and personal experiences to her writing. Learn about our editorial policy Marcia Purse Medically reviewed by Medically reviewed by Steven Gans, MD on January 11, 2020 Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital. Learn about our Medical Review Board Steven Gans, MD Updated on February 18, 2020 GregorBister/Getty Images More in Bipolar Disorder Treatment Medications Symptoms Diagnosis In This Article Table of Contents Expand Causes Risk Factors Symptoms Diagnosis Treatment SSRI Discontinuation Syndrome View All Back To Top Serotonin syndrome is a potentially life-threatening condition thats caused by elevated serotonin concentrations in your system from certain medications. Serotonin is a chemical called a neurotransmitter that communicates with nerve cells and has a wide variety of functions throughout your body, primarily in your central nervous system and intestines. In the right amounts, serotonin is necessary, but when your body builds up too much and your levels get too high, symptoms can range from unpleasant to severe. If its left untreated, serotonin syndrome can potentially lead to death.?? Causes Serotonin syndrome, also known as serotonin toxicity, happens as the result of taking serotonergic drugs, medications that affect the level of serotonin in your body. It may be brought on by several different circumstances including:?? Taking one serotonergic medication: Its unlikely that using one serotonergic medication by itself will cause serotonin syndrome, but it can happen in certain people who are sensitive to serotonin, especially when the dose is increased.Overdosing: You can end up with serotonin syndrome if you ingest too much of your serotonergic medication(s), whether or not its purposeful.Taking two serotonergic medications together: The majority of cases involve a person taking two (or more) serotonergic drugs at the same time, often without realizing it. The medications that are most often associated with serotonin syndrome are antidepressants such as:?? Selective serotonin reuptake inhibitors (SSRIs) like Paxil (paroxetine), Prozac (fluoxetine), and Celexa (citalopram)Wellbutrin (bupropion), which is also used for smoking cessation under the brand name ZybanSerotonin and norepinephrine reuptake inhibitors (SNRIs) like Cymbalta (duloxetine), Pristiq (desvenlafaxine), and Effexor (venlafaxine)Tricyclic antidepressants such as amitriptyline, Pamelor (nortriptyline), and Surmontil (trimipramine)Monoamine oxidase inhibitors (MAOIs) like Nardil (phenelzine) and Parnate (tranylcypromine) There are other medications that are also considered serotonergic drugs, though they may not be as well-known.?? Some examples of these include: Migraine medications called triptans such as Axert (almotriptan), Amerge (naratriptan), Imitrex (sumatriptan), and Maxalt (rizatriptan)??Anticonvulsants like Tegretol (carbamazepine) and Depakene (valproic acid), which are used for migraines, epilepsy, and bipolar disorderOpioid pain medications such as Ultram (tramadol), codeine (Tylenol with codeine), Demerol (meperidine), Talwin (pentazocine), and Oxycontin (oxycodone)5-HT3 receptor antagonists, which treat nausea, like Anzemet (dolasetron), granisetron, Zofran (ondansetron), and Aloxi (palonosetron)Reglan (metoclopramide), a prokinetic medication thats used to treat gastroesophageal reflux disease (GERD), diabetes, and sometimes to treat nausea in chemotherapy patientsOver-the-Counter cough and cold medications that contain dextromethorphan like Childrens Robitussin Cough Long-Acting, Vicks DayQuil Cough, Vicks Formula 44 Custom Care Dry Cough, Zicam Cough MAX, and many others, including a combination cough and cold medications t hat have dextromethorphan in themErgot derivatives, including Ergomar (ergotamine) for migraines and Methergine (methylergonovine) for uterine bleeding after childbirthA muscle relaxant called Amrix (cyclobenzaprine)Buspirone, a medication thats prescribed for anxiety disorders Other substances and supplements that can contribute to serotonin syndrome include:?? St. Johns WortIllegal/illicit drugs such as cocaine, amphetamines, ecstasy, and LSDL-tryptophan, an over-the-counter amino acid supplement that people use to quit smoking, for mental health disorders, and to help athletic performanceLithobid (lithium), a mood stabilizer thats often used to treat bipolar disorder All of these drugs and substances affect serotonin in some way. Some block nerve receptors; some block reuptake; some slow the breakdown of serotonin; and some increase the release of serotonin. Because so many medications can contribute to serotonin syndrome, its essential that any doctors you see who prescribe you medication always know about all the over-the-counter and prescription medications and supplements youre currently taking. Risk Factors Your risk of developing serotonin syndrome goes up under these circumstances:?? You just started taking a serotonergic medication like one of those mentioned above or you had your dose increased. Some peoples bodies are naturally slower than others are at metabolizing serotonin, and this isnt something you or your doctor will know until you are on a drug that boosts serotonin. Most cases of serotonin syndrome start within 24 hours after starting or increasing a serotonergic medication and the majority of those start within six hours. Youre switching from an MAOI to another antidepressant or vice versa. Almost all antidepressants contain a warning that you should wait for at least two weeks, and sometimes more, when you switch antidepressant types. One of the main reasons for this is the danger that having both types of drugs in your system can lead to serotonin syndrome. Prozac (fluoxetine) in particular takes several weeks to be flushed out of your body.Youre taking more than one serotonergic medication, supplement, or substance at the same time. For instance, youre on Wellbutrin for depression and you take an Imitrex for a migraine or youre taking Zoloft (sertraline) and you treat a cold with DayQuil. Symptoms Symptoms of serotonin syndrome can be mild to severe indicating anything from a slight serotonin excess to a life-threatening syndrome. The most common symptoms include:?? Sudden jerky or shock-like movementsFlushing or palenessSlow or fast pulseFeverHeadacheAnxietyMuscle rigidityConfusionRestlessnessProfuse sweatingTremorDilated pupilsPoor coordinationRapid breathingIrregular heartbeatHigh blood pressureShivering If your condition becomes severe, it can turn into a life-threatening situation and may include signs like:High feverSudden swings in your blood pressure and/or pulseSeizuresLosing consciousness If you suspect you or a loved one is showing signs of serotonin syndrome, contact your doctor immediately. If your symptoms are getting worse or theyre severe, head to the emergency room, or call 911. Quick treatment is important because you can become seriously ill and your condition can become fatal the longer you go untreated. Diagnosis Because the symptoms are similar to many other issues, you wont be diagnosed with serotonin syndrome until every other possible diagnosis has been ruled out. This is mainly because serotonin syndrome has to be diagnosed purely on your symptoms, history, and your physical and neurological exam. Other conditions that you will likely have ruled out include:?? Neuroleptic malignant syndrome (NMS), another drug-related disorder that has some of the same symptoms as serotonin syndrome but results from antipsychotics. The biggest difference is that serotonin syndrome generally comes on quickly after starting the trigger medication.Infections like meningitis and encephalitisAn overdose of a substance like cocaine.Withdrawal from alcohol or drugsIntoxicationReactions to other medications The tests you may have to rule these conditions out include: Blood tests such as a complete blood count (CBC), blood cultures to test for infection, and other blood tests that check your electrolytes, screen for drugs and alcohol, and check your kidney, thyroid, and liver functionUrine tests to screen for drugs and alcohol, as well as to look at your kidney functionComputed tomography (CT) scan of your brainElectrocardiogram (ECT) to check your heartLumbar puncture (spinal tap) to evaluate your spinal fluidChest X-ray Treatment Once youve been diagnosed with serotonin syndrome, the first line of treatment is to discontinue all serotonergic drugs.?? Benzodiazepines like Valium (diazepam) or Ativan (lorazepam) may be helpful to relieve any muscular symptoms, and you may need supportive treatment like oxygen and intravenous (IV) fluids and stabilization of vital signs. Drugs that specifically act against serotonin, called serotonin antagonists, can potentially be useful. For mild to moderate cases, your symptoms should subside within 24 to 72 hours once youve discontinued taking the serotonergic drug and you can expect to fully recover. If your symptoms are worrisome, your doctor may have you hospitalized until youre stabilized. In cases where youre exhibiting signs of severe serotonin syndrome, youll likely need to be hospitalized in the intensive care unit (ICU) until all your symptoms are gone. For high fever, you may need to be sedated and given a medication that keeps you still (paralytic) to avoid any more damage to your muscles. Youll also have a breathing tube and ventilator. SSRI Discontinuation Syndrome It should be noted that some of the same symptoms listed above may also occur when you abruptly stop taking an antidepressant or you taper it off too quickly, known as SSRI discontinuation syndrome. ??Agitation, headaches, shock-like sensations, poor coordination, chills, and impaired concentration are some of the characteristics common to both syndromes. Because of this risk, its vital that you never stop taking your antidepressant abruptly without discussing with your doctor.