SEROTONIN SYNDROME

MEDICATIONS AND SEROTONIN SYNDROME
On July 19, 2006, the U.S. Food and Drug Administration issued a warning of increased risk of serotonin syndrome as a result of comibining slective serotonin reuptake inhibitors (SSRIs) and selective serotonin norepinephrine reuptake inhibitors (SSNRIs) with migraine headache medications called triptans.
Selective Serotinin Reuptake Inhibitors (SSRIs)
It is believed that the brain contains several hundred different types of chemical messengers (neurotransmmitters) that act as communcation agents between different brain cells. Serotonin is a neurotransmitter that is important in regulating a variety of body functions and feelings. Low serotonin levels have been linked to depression and anxiety.
SSRIs inhibit the reuptake of serotinin in the brain. Reuptake is a process where neorotransmitters in the brain are reabsorbed and deactivated or recycled for future use. This causes an incrase of serotinin levels, resulting in improved mood, decreased anxiety and inhibition of panic. SSRIs are considered a first-line treatment for panic disorder and include:
Celexa (citalopram)
Luvox (fluvoxamine)
Prozac (flouxetine)
Paxil (paroxetine)
Zoloft (sertraline)
Selctive Serotinin-Norepinephrine Reuptake Inhibitors (SSNRIs)
SSNRSs inhibit the reabsorption of serotonin and norepinephrine in the brain Norepinephrine is chemical messenger in the brain that influences sleep and alertness. It is believed to be correlated to the fight-or-flight stress response.
SSNRIs include:
Cymbalta (duloxetine)
Effexor, Effexor XR (venlaxine)
Triptans
Triptans are a class of drugs commonly used to treat migraine or cluster headaches. They act on serotonin receptors in the brain, thereby affecting serotonin levels.
Examples of triptans include:
Amerge (naratriptan)
Axert (amotriptan)
Frova (frovatriptan)
Imitreex (sumatriptan)
Maxalt and Maxalt-MLT (rizetriptan)
Relpax (eletriptan)
Zomig and Zomig ZMT (zolmitriptan)
In addition to the medications indentified in the FDA advisory, other drugs associated with alterations of serotonin levels in the brain, increasining the risk of serotonin syndrome.
Tricyclic Antidepressants
Tricyclic antidpressants (TCAs) are named after the drugs “three ringed” molecular structure. Prior to the introduction of SSRSs in the late 1980s, TCAs were the medication of choice for the treatment of major depressive disorder, panic disorder and other anxiety disorders. TCAs are also used to treat certain pain syndromes and nocturnal enuresis (bedwetting). It is believed that TCAs function to increase levels norepinephrine and serotonin in the brain.
Examples of TCAs include:
Elavil (amitriptyline)
Tofranil (Imipramine)
Sinequan (doxepin)
Anafranil (clomipramine)
Monoamine Oxidase Inhibitors (MAOIs)
MAOIs are a class of antidepressants believed to increase levels of norepinephrine, serotonin and dopamine in the brain. They are effective for the treatment of a major depressive disorder, panic disorder and other anxiety disorders. Because of potentially dangerous interactions with certain foods, beverages, and other drugs, MAOIs are usually considered a last resort therapy.
Examples of MAOIs include:
Nardil (phenelzine)
Parnate (tranylcypromine)
Marplan (isocarboxazid)
Emsam (selegiline)
Other Antidepressants
Examples of other antidepressants include:
Wellbutrin (bupropion)
Desyrel (trazadone)
Other Psychiatric Medications
BuSpar (buspirone)
Eskalith (lithium)
Analgesics (Pain Killers)
Codeine
Fentanyl
Tramadol
Antibiotic/Antireetroviral Medications
Zyvox (linezolid)
Norvir (ritonavir)
Herbal Drugs (Dietary Supplements
Hypericum Perforatum (St. John's Wort)
Ginseng/Panax
Street Drugs
Amphetamines
Cocaine
LSD (lysergic acid diethylamide)
SEROTONIN SYNDROME
What is Serotonin Syndrome?
The human brain is believed to function in a xomplex chemical environment through various types of neurons and neurotransmitters. Neurons are brain cells, numbering in the billions, that are capable of instant communication with each other through chemical messengers called neurotransmitters. Serotonin is one of these chemical messengers. It plays a role in modulating anxiety, mood, sleep, appetite and sexuality. Serotonin is also produced in the digestive tract, playing a role in digestion and other bodily processes.
The antidepressants called selective serotonin reuptake inhibitors (SSRIs) are considered to be first-line agents in the treatment of panic disorder and other anxiety disorders. SSRIs increase the level of serotonin in the brain, resulting in decreased anxiety and inhibition of panic attacks. But, if serotinin levels increase too much, a serious medical condition may result.
Serotonin Syndrome
Serotonin syndrome, or serotonin toxicity, is a rare condition caused by dangerously high levels of serotonin in the brain. It can be potentially life-threatening. It is generally caused by mixing two or more medications that affect serotonin levels in the brain. SSRIs, SNRIs, tricyclic antidepressants, MAOIs and triptans are all classes of medications that have been implicated in the development of serotonin syndrome.
Signs and Symptoms
Signs and symptoms of serotonin syndrome include:
Confusion
Loss of coordination
Muscle rigidity
Restlessness
Hallucinations
Extreme agitation
Flucutations in blood pressure
Heart palpitations
Nausea, vomiting, diarrhea
Fever
Seizures
Coma
Treatment
Since serotonin synndrome can be potentially life-threatening, emergency medical treatment is necessary. Treatment beins with the withdrawal of the causative medications. The direct effects of serotonin syndrome tend to abate in 24 to 48 hours after the drugs affecting serotonin are stopped. However, some of the complications such as delirium and instability of heart rate, blood pressure, temperature and other functions of the autonomic nervous system may persist longer. Supportive measures and interventions in a hospital setting may be necessary and include:
Heart rate and blood pressure control. Medications to decrease heart rate and blood pressure (I.e., esmolol or nitroprusside( may be needed. Medications may also be given if blood pressure is too low.
Temperature Control. It may be necessary to treat fever symptoms with cooling blankets and bedside fans.
Sedation. Benzodiazepines may be used to help control muscle rigidity and extreme agitation.
Hydration. Intravenous fluids may be needed to address hydration needs.
Cyprohetadine is sometimes used to block serotonin production in the body. It has demonstrated effectiveness in reducing the severity of the symptoms associated with serotonin syndrome.
Prevention
Tell your doctor about all medications you are currently taking. This includes prescription drugs, over-the-counter medications and supplements.
If you are taking a medicaation that affects serotonin levels, talk to your doctor about your risks
for developing serotonin syndrome.
Seek immediate medical care if you are taking a medication that affects serotonin levels, and you develop any of the symptoms of serotonin syndrome.