Vomiting is controlled by the vomiting center in the medulla. Vomiting center is activated by either one of four trigger zones: chemoreceptor trigger zone, vestibular nuclei, cerebral cortex and gastrointestinal tract. Vomiting center is controlled by serotonin (5-HT3), muscarinic and histamine (H1) receptors.
Chemoreceptor trigger zone is sensitive to chemical stimuli, such as opioids and cytotoxic drugs. It is under the control of dopamine, serotonin (5-HT3) and opioid receptors.
Vestibular nuclei is controlled by muscarinic and histamine (H1) receptors. This is activated in vertigo or motion sickness.
Cerebral cortex activates vomiting from smell, thought and so on. Gastrointestinal tract has serotonin (5-HT3) receptors, which are affected by chemotherapeutic drugs.
Different classes of drugs work on different receptors and act as antiemetics and antivertigo agents.
Please refer to the drug classes listed below for further information.