# NK1 receptor (TACR1)

Source: https://onco.cc/targets/tacr1/  
OnCo record `tacr1` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The substance P receptor that drives the delayed nausea felt in the days after chemotherapy. Aprepitant and netupitant block it and are combined with a 5-HT3 blocker and dexamethasone for the most nausea-provoking regimens.

## Summary

Substance P acting on neurokinin 1 receptors in the brainstem mediates the delayed phase of chemotherapy-induced nausea and vomiting, which 5-HT3 antagonists control poorly. Aprepitant, approved in 2003, was the first NK1 antagonist; fosaprepitant, rolapitant and the netupitant-palonosetron combination followed. Adding an NK1 antagonist to a 5-HT3 antagonist and dexamethasone is the guideline standard for highly emetogenic chemotherapy such as cisplatin and anthracycline-cyclophosphamide, and it interacts with drugs metabolised by CYP3A4, so dexamethasone doses are reduced.

## Fields

- Kind: Target
- Last checked: 2026-09-04
- Symbol: TACR1
- Class: other
- Biology: G protein-coupled receptor for substance P in the nucleus tractus solitarius and area postrema; blocked by pitant antiemetics.
- Where found: Supportive care: prevention of delayed chemotherapy-induced nausea and vomiting

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Tachykinin_receptor_1
- UniProt P25103: TACR1: https://www.uniprot.org/uniprotkb/P25103/entry

## Connected records

- targets: [5-HT3 receptor (HTR3A)](https://onco.cc/targets/htr3a/), [Cannabinoid receptor 1](https://onco.cc/targets/cnr1/)
- drugs: [Aprepitant (and fosaprepitant)](https://onco.cc/drugs/aprepitant/), [Dexamethasone](https://onco.cc/drugs/dexamethasone/), [Netupitant and palonosetron](https://onco.cc/drugs/netupitant-palonosetron/), [Rolapitant](https://onco.cc/drugs/rolapitant/)

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JSON: https://onco.cc/api/v1/entities/tacr1.json