Drug General Information (ID: DDIQMXHFUW)
  Drug Name Ondansetron Drug Info Oxitriptan Drug Info
  Drug Type Small molecule Small molecule
  Therapeutic Class Antiemetics Antidepressants
  Structure

 Mechanism of Ondansetron-Oxitriptan Interaction (Severity Level: Major)
     Additive serotonergic effects Click to Show/Hide Mechanism Graph
Could Not Find 2D Structure
      Drug Name Ondansetron Oxitriptan
      Mechanism Serotonergic effects
5-HT 3 receptor  Antagonist
Serotonergic effects
5-HT receptor  Agonist
      Key Mechanism Factor 1
Factor Name 5-HT 3 receptor Structure Sequence
Protein Family Ligand-gated ion channel (TC 1.A.9) family
Protein Function
This is one of the several different receptors for 5-hydroxytryptamine (serotonin), a biogenic hormone that functions as a neurotransmitter, a hormone, and a mitogen. This receptor is a ligand-gated ion channel, which when activated causes fast, depolarizing responses in neurons. It is a cation-specific, but otherwise relatively nonselective, ion channel.
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      Key Mechanism Factor 2
Factor Name 5-HT receptor Structure Sequence
Protein Family G-protein coupled receptor 1 family
Protein Function
G-protein coupled receptor for 5-hydroxytryptamine (serotonin) (PubMed:1330647, PubMed:18703043, PubMed:19057895). Also functions as a receptor for various drugs and psychoactive substances, including mescaline, psilocybin, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) and lysergic acid diethylamide (LSD) (PubMed:28129538). Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of down-stream effectors (PubMed:28129538). Beta-arrestin family members inhibit signaling via G proteins and mediate activation of alternative signaling pathways (PubMed:28129538). Signaling activates phospholipase C and a phosphatidylinositol-calcium second messenger system that modulates the activity of phosphatidylinositol 3-kinase and promotes the release of Ca(2+) ions from intracellular stores (PubMed:18703043, PubMed:28129538). Affects neural activity, perception, cognition and mood (PubMed:18297054). Plays a role in the regulation of behavior, including responses to anxiogenic situations and psychoactive substances. Plays a role in intestinal smooth muscle contraction, and may play a role in arterial vasoconstriction.
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      Mechanism Description
  • Additive serotonergic effects by the combination of Ondansetron and Oxitriptan 

Recommended Action
      Management Caution is advised if 5-HT3 receptor antagonists are prescribed with other agents that affect the serotonergic neurotransmitter system. Patients should be closely monitored for symptoms of the serotonin syndrome during treatment. Particular caution is warranted when initiating or increasing the dosages of these agents. The potential risk for serotonin syndrome should be considered even when administering serotonergic agents sequentially, as some agents may demonstrate a prolonged elimination half-life. For example, a 5-week washout period is typically recommended following use of fluoxetine and 2 weeks following use of MAOIs before administering another serotonergic agent. If serotonin syndrome develops or is suspected during the course of therapy, all serotonergic agents should be discontinued immediately and supportive care rendered as necessary.

References
1 Cerner Multum, Inc. "Australian Product Information.".
2 Cerner Multum, Inc. "UK Summary of Product Characteristics.".
3 Product Information. Akynzeo (netupitant-palonosetron). Eisai Inc, Woodcliff Lake, NJ.