Metabolism serotonin receptors

Pharmacology Lithium alters sodium transport in nerve and muscle cells, and effects a shift toward intraneuronal catecholamine metabolism. The specific mechanism in mania is unknown, but it affects neurotransmitters associated with affective disorders. Its antimanic effects may be the result of increases in norepinephrine reuptake and increased serotonin receptor sensitivity. Pharmacokinetics ... 

Mechanism of Action A benzisoxazole derivative that may antagonize dopamine and serotonin receptors. Therapeutic Effect Suppresses psychotic behavior. Pharmacokinetics Well absorbed from the G1 tract unaffected by food. Protein binding 90%, Extensively metabolized in the liver to active metabolite. Primarily excreted in urine. Half-life 3-20 hr metabolite 21-30 hr (increased in elderly). 

At least 14 distinct types of serotonin receptors (5-5-HTjg, 5-HT2A, etc.) have been identified. They are present in the heart, in gastrointestinal tissues, adrenal and other glands, and bone as well as in the brain. Drugs, such as sumatriptan (Fig. 30-28), which activate serotonin receptors are important in the treatment of migraine. This common disorder of serotonin metabolism is characterized by severe or moderately severe headache and a variety of other symptoms, which are frequently preceded by a visual aura. Serotonin is removed from synapses via a... 

Autacoids are endogenous molecules with powerful pharmacologic effects but poorly defined physiologic roles. Histamine and serotonin (5-hydroxytryptamine 5-HT) are two of the most important autacoids. Both are synthesized in the body from amino acid precursors and then eliminated by amine oxidation the pathways of synthesis and metabolism are very similar to those used for catecholamine synthesis and metabolism. The ergot alkaloids are a heterogeneous group of drugs that interact with serotonin receptors, dopamine receptors, and alpha receptors. They are included in this chapter because of their effects on serotonin receptors and on smooth muscle. 

Meperidine is thought to inhibit both the 5-HT2A receptors and norepinephrine (NE) reuptake mechanism which may precipitate a serotonin syndrome, a toxic state secondary to excessive serotonin ago-nism of the CNS [3,4]. This adverse drug reaction occurs most commonly in patients who are using single or multiple medications that increase postsy-naptic serotonin levels. Inherited deficiencies in the metabolism of serotonin may contribute to the development of the syndrome. Hypertension, atherosclerosis, and hyperlipidemia are all associated with a reduction in endothelial MAO activity and thus a reduced capacity to metabolize serotonin may increase the risk of a serotonin crisis. The diagnosis... 

---