MRCP UK EXAMINATIONS

Detailed explanation-1: -The chemoreceptor trigger zone (CTZ) is an area of the medulla oblongata that receives inputs from blood-borne drugs or hormones, and communicates with other structures in the vomiting center to initiate vomiting.

Detailed explanation-2: -Chemotherapy-induced nausea and vomiting (CINV) is triggered by stimulation of the chemoreceptor trigger zone (CTZ), which is located in the area postrema in the floor of the 4th ventricle of the brain (Figure 11). It is sensitive to chemical stimulation from cerebral spinal fluid and blood.

Detailed explanation-3: -Apomorphine (6.25-Mg Tablets) Apomorphine acts directly on the chemoreceptor trigger zone to induce emesis. Apomorphine is generally the emetic of choice in dogs because of its rapid onset and the ability to reverse its action. Apomorphine is given at a dose of 0.02 to 0.04 mg/kg intravenous (IV) or intramuscular (IM).

Detailed explanation-4: -Opiate Receptors. Though the exact physiological mechanisms underpinning opioids-induced nausea and vomiting are not fully understood, activation of opiate receptors in the area postrema, vestibular apparatus and the gastrointestinal tract are implicated [14].