Serotonin syndrome: Mechanisms and complications

A dangerous complication of serotonin syndrome is severe muscle spasms, which damage and degrade muscle tissue. Muscle spasms can also lead to severe kidney damage, so drugs that temporarily paralyze muscles must be used to prevent damage and assist with mechanical ventilation.

Serotonin is an important chemical mediator for the central nervous system, which is considered a neurotransmitter. Serotonin has effects on target organs such as blood, digestive, nervous, cardiovascular, urinary... If there is a low amount of serotonin in the blood, it will not cause any dangerous signs, however, When serotonin is high in the blood, it will lead to Serotonin syndrome, affecting the patient's life.
About the cause of serotonin syndrome, it is the result of a serious drug interaction. When Serotonin is used together with other drugs that increase or stabilize serotonin, it will cause serotonin levels to be too high, thereby leading to behaviors such as restlessness, tremors, difficulty in coordination, walking unsteadily, convulsions, fever with chills and diarrhea. These symptoms make the patient uncomfortable, severe cases will disrupt the automatic system and lead to death.
Drugs that can lead to serotonin syndrome if not used correctly are:
Antidepressants such as: Selective serotonin reuptake inhibitors; norepinephrine and serotonin reuptake inhibitors; tricyclic antidepressants; monoamine oxidase inhibitors; other antidepressants such as Wellbutrin. Medicines used to treat migraines such as Axert, Amerge, Imitrex. Illegal drugs like LSD, Ecstasy, Cocaine or Amphetamine Herbal supplements like St. John's wort (banana extract), cough and cold medicine, ginseng.

Serotonin is a neurotransmitter derived from L-tryptophan. Serotonin is found in the peripheral smooth muscle and digestive system as well as in the Raphe nucleus in the brain stem. Activation of central serotonin helps the body regulate wakefulness, thermoregulation as well as emotional behavior, vomiting and sexual behaviors. And peripheral serotonin activation will have a mechanism to regulate intestinal motility and vascular tone. The seven serotonin receptors are divided into subtypes, and studies show that [5-HT]2A receptors are most closely associated with serotonin syndrome, and [5HT]1A to a lesser extent.
In addition, multiple therapeutic mechanisms can also cause overstimulation of serotonin receptors, which in turn leads to either direct hyperstimulation of serotonin receptors, or mechanisms, to increased serotonin levels. in the synapse.
In addition, CYP3A4 and CYP2D6 are also involved in the regulation of serotonin metabolism. Specifically, if the patient has a gene mutation in these enzymes or the patient is taking drugs such as fluoxetin, protease inhibitors, paroxetin and azole antifungals that inhibit the enzyme, it may lead to decreased metabolism. serotonin chemistry. This causes serotonin to increase in the synaptic cleft leading to a range of signs and symptoms of serotonin syndrome.

Most cases of serotonin syndrome will manifest within 24 hours of changing the dose or starting a new medication. Symptoms of the disease depend on whether there is low or high serotonin in the blood. Symptoms can be classified into the following categories:
Change in mental status: The patient presents with anxiety, agitation and restlessness, delirium as well as easy startling; Autonomic epilepsy: At this sign, the patient appears tachycardia, increased blood pressure, increased body temperature, tremor, vomiting and diarrhea; Patients also show signs of myocardial infarction, increased muscle tone, molluscum, hyperreactivity, clonus,... Symptoms of the disease usually disappear within 24 hours, however symptoms may persist longer after the use of drugs with long half-lives or active ingredients. But if the treatment of symptoms is delayed or not according to the regimen, dangerous complications can occur for the patient. A dangerous complication of serotonin syndrome is severe muscle spasms that damage and degrade muscle tissue. Muscle spasms can also lead to severe kidney damage, so drugs that temporarily paralyze muscles must be used to prevent damage and assist with mechanical ventilation.

The primary treatment of serotonin syndrome is elimination of the drugs causing the syndrome and intensive care. However, the management of serotonin syndrome depends on the severity of the disease. Specifically:
If serotonin levels are low and symptoms are mild, the main treatment is to stop the suspected drugs and monitor the patient's condition. Symptoms should disappear after 24 hours. In case of early gastrointestinal poisoning before 6 hours, gastric lavage and activated charcoal may be indicated for the purpose of eliminating drugs that cause serotonin syndrome. Treatment to reduce fever is by applying cool compresses, taking antipyretics, giving fluids, and using sedatives as well as drugs that slow the heart rate and lower blood pressure. In case the patient has severe respiratory failure, it is necessary to give oxygen or intubate, mechanical ventilation... To reduce the production of active serotonin, a specific treatment drug, cyproheptadine, can be used. However, this method needs to follow the prescription of a specialist. To treat symptoms of agitation, decreased muscle tone, and anticonvulsants, use benzodiazepines (Diazepam, Lorazepam). At the same time, use more cardiovascular drugs if the patient lowers blood pressure, reduces heart rate. Serotonin syndrome is common and can be life-threatening, but it is completely preventable if the patient and the doctor pay attention to the side effects of the drugs that can lead to depression. This syndrome then has methods of monitoring and prevention during the treatment of the disease.
In case of suspected serotonin syndrome, it is necessary to go to a reputable hospital for timely examination and treatment. Currently, Vinmec International General Hospital is one of the leading prestigious hospitals in the country, trusted by a large number of patients for medical examination and treatment. Not only the physical system, modern equipment: 6 ultrasound rooms, 4 DR X-ray rooms (1 full-axis machine, 1 light machine, 1 general machine and 1 mammography machine) , 2 DR portable X-ray machines, 2 multi-row CT scanner rooms (1 128 rows and 1 16 arrays), 2 Magnetic resonance imaging rooms (1 3 Tesla and 1 1.5 Tesla), 1 room for 2 levels of interventional angiography and 1 room to measure bone mineral density.... Vinmec is also the place to gather a team of experienced doctors and nurses who will greatly assist in diagnosis and detection. early signs of abnormality in the patient's body. In particular, with a space designed according to 5-star hotel standards, Vinmec ensures to bring the patient the most comfort, friendliness and peace of mind.