Serotonin syndrome rigidity

MDMA overdose as well as the concomitant consumption of selective serotonin reuptake inhibitors (SSRI) with other dmgs that exert serotoninergic effects (such as inhibitors of monoamine oxidase) can rapidly lead to the serotonin syndrome. Its symptoms, which are reversible upon cessation, of the drug include confusion, muscle rigidity in the lower limbs, and hyperthermia suggesting an acute reaction to serotonin overflow in the CNS. Blocking the function of SERT outside the brain causes side effects (e.g., nausea), which may be due to elevated 5HT however , impairment of transporter function is not equivalent to direct activation of 5HT recqrtors in causing adverse effects such as fibrosis and pulmonary hypertension. 

In addition to this serious diet-drug interaction, irreversible MAOIs also potentiate the effects of sympathomimetic drugs like ephedrine found in over-the-counter cold remedies and recreational stimulants like amphetamine. The MAOIs also interact with drugs that increase synaptic concentrations of 5-HT, such as the tricyclic antidepressant clomipramine and the herbal SSRI antidepressant St John s wort (Hypericum spp.). The resulting serotonin syndrome is characterised by hyperthermia and muscle rigidity. While devoid of these side effects the reversible MAO-A inhibitor moclobemide has yet to establish itself as a first-line alternative to the SSRIs. 

Serotonin syndrome Some TCAs inhibit neuronal reuptake of serotonin and can increase synaptic serotonin levels (eg, clomipramine, amitriptyline). Either therapeutic or excessive doses of these drugs, in combination with other drugs that also increase synaptic serotonin levels (such as MAOIs), can cause a serotonin syndrome consisting of tremor, agitation, delirium, rigidity, myoclonus, hyperthermia, and obtundation. 

Serious toxic reactions with delirium can arise when specific serotonin reuptake inhibitors (SSRIs) are taken with other drugs that increase central and peripheral serotonergic activity. Known as the serotonin syndrome , this reaction consists of excitation, restlessness, fluctuations in consciousness, with tremor, rigidity, myoclonus, sweating, flushing, pyrexia, cardiovascular changes, and rarely coma and death (Sternbach, 1991). The syndrome has occurred when SSRIs have been combined with irreversible monoamine oxidase... 

Excess serotonin in the central nervous system leads to a condition commonly referred to as the serotonin syndrome. There are several drug mechanisms that can cause serotonin toxicity. Serotonin toxicity can be a medical emergency characterised by rapid onset of severe hyperthermia, muscle rigidity and multiple organ failure. 

Co-administration with other serotonergic drugs can result in development of the serotonin syndrome. In this, the patient is initially restless and may have nausea or diarrhoea. Hyperthermia, rigidity, tremor, myoclonus, autonomic instability, and convulsions may... 

The combination of increased stores of the monoamine plus inhibition of reuptake after release is thought to result in marked increases of serotonin in the synapses, leading to a serotonin syndrome. This sometimes fatal syndrome includes hyperthermia, muscle rigidity, myoclonus, and rapid changes in mental status and vital signs. 

A 23-year-old woman had some of the features of the serotonin syndrome (mental status changes, sweating, tremor, and fever) however, the large rise in creatine kinase activity, extreme lead-pipe rigidity, and the abrupt onset suggested neuroleptic malignant syndrome rather than the serotonin syndrome (104). 

Drug interactions serotonin syndrome includes diaphoresis, rigidity, myoclonus, hyperthermia, ANS instability, and seizures. Has been reported for SSRIs when used with MAOIs, TCAs, meperidine, and dextromethorphan. 

Selective serotonin reuptake inhibitors MAO inhibitors, meperidine, tricyclic antidepressants Serotonin syndrome hypertension, tachycardia, muscle rigidity, hyperthermia, seizures... 

Serotonin syndrome occurs primarily in patients taking monoamine oxidase (MAO) inhibitors (see p 269) who also take serotonin-enhancing drugs, such as meperidine (Demerol ), fluoxetine (Prozac ), or other serotonin reuptake inhibitors (SSRIs see Antidepressants, p 88), and is characterized by irritability, rigidity, myoclonus, diaphoresis, autonomic instability, and hyperthermia. It may also occur in people taking an overdose of or combinations of SSRIs even without concurrent use of MAO inhibitors. 

Rigidity may also be seen with a number of toxins and may be caused by CNS effects or spinal cord stimulation. Neuroleptic malignant syndrome and serotonin syndrome (see p 22) are characterized by rigidity, hyperthermia, metabolic acidosis, and an tered mental status. Rigidity seen with malignant hyperthermia (see p 22) is caused by a defect at the muscle cell level and may not reverse with neuromuscular blockade. 

C. Chronic use has been associated with bone marrow depression, hepatitis, renal disease, cardiomyopathy, hyponatremia, and exfoliative dermatitis. Carbamazepine has also been implicated in rigidity-hyperthermia syndromes (eg, neuroleptic malignant syndrome and serotonin syndrome) in combination with other drugs. 

C. Serotonin syndrome (see p 22). Severe hyperthermia, muscle rigidity, and hypertension may occur with therapeutic doses in patients taking monoamine oxidase inhibitors (p 269). 

B. lit addition, severe rigidity and hyperthermia may occur when patients receiving MAO inhibitors use therapeutic doses of meperidine (Demeroi), dextromethorphan, fluoxetine (Prozac), paroxetine (Paxii), sertraiine (Zoloft), ven-lafaxine (Effexor), or tryptophan the mechanism is unknown but may be related to inhibition of serotonin metabolism in the CNS, resulting in serotonin syndrome (see p 22). 

A severe case of the serotonin syndrome (including hyperthermia and muscle rigidity requiring mechanical ventilation) has been reported in a patient who took an overdose of moclobemide, clomipramine and buspirone , (p.l 149). Concurrent use of more than one serotonergic drug is thought to be a risk factor for the development of the serotonin syndrome , (p.9). 

Citalopram Citalopram is a substrate of CYP2C19, and inhibition of its metabolism by fluconazole can result in serotonin syndrome, as occurred in two patients, who developed prolonged delirium without tremor, myoclonus, rigidity, or autonomic instability [30 ]. Serotonin toxicity in patients with cancers may not present with the classic constellation of signs and symptoms and delirium may be the only presenting feature. 

---