| Indication |
Only for the treatment of symptoms of severe diarrhea-predominant
irritable bowel syndrome (IBS) in women with chronic symptoms (generally
lasting greater than 6 months) who does not present with anatomic or
biochemical GI abnormalities and have not responded to conventional
therapy. |
| Pharmacodynamics |
Alosetron is a potent and selective antagonist of the serotonin 5-HT3
receptor type. Activation of these receptors and the resulting neuronal
depolarization affects the regulation of visceral pain, colonic
transit, and GI secretions processes that are related to IBS. By
blocking these receptors, alosetron is able to effectively control IBS. |
| Mechanism of action |
Alosetron is a potent and selective 5-HT3 receptor antagonist. 5-HT3
receptors are nonselective cation channels that are extensively
distributed on enteric neurons in the human gastrointestinal tract, as
well as other peripheral and central locations. Activation of these
channels and the resulting neuronal depolarization affect the regulation
of visceral pain, colonic transit and gastrointestinal secretions,
processes that relate to the pathophysiology of irritable bowel syndrome
(IBS). 5-HT3 receptor antagonists such as alosetron inhibit
activation of non-selective cation channels which results in the
modulation of serotonin-sensitive GI motor and sensory processes. |
| Absorption |
50-60 % |
| Volume of distribution |
|
| Protein binding |
82% |
| Metabolism |
Hepatic, via microsomal cytochrome P450 (CYP) |
| Route of elimination |
Renal elimination of unchanged alosetron accounts for only 6% of the dose. Alosetron is extensively metabolized in humans. |
| Half life |
1.5 hours |
| Clearance |
|
| Toxicity |
Not Available |
