Fosaprepitant

Definition

Fosaprepitant is a prodrug of aprepitant, a highly selective neurokinin-1 (NK1) receptor antagonist used as an antiemetic medication to prevent and treat nausea and vomiting associated with chemotherapy and other medical treatments.

5 Must Know Facts For Your Next Test

1. Fosaprepitant is a water-soluble prodrug of aprepitant that can be administered intravenously, allowing for rapid conversion to the active drug.
2. Fosaprepitant is used to prevent acute and delayed chemotherapy-induced nausea and vomiting (CINV) in adults receiving highly emetogenic chemotherapy.
3. The mechanism of action of fosaprepitant/aprepitant involves blocking the binding of substance P to NK1 receptors in the central and peripheral nervous system, thereby interrupting the vomiting reflex.
4. Fosaprepitant is typically administered as a single-dose intravenous infusion on the first day of a chemotherapy regimen, followed by oral aprepitant on subsequent days.
5. Fosaprepitant has improved bioavailability compared to oral aprepitant, allowing for a more convenient single-dose administration.

Review Questions

• Explain the role of fosaprepitant in the prevention and treatment of chemotherapy-induced nausea and vomiting (CINV).
  • Fosaprepitant is a prodrug that is rapidly converted to the active compound aprepitant, a highly selective neurokinin-1 (NK1) receptor antagonist. By blocking the binding of substance P, a key neurotransmitter involved in the vomiting reflex, fosaprepitant/aprepitant effectively interrupts the physiological pathway that leads to nausea and vomiting associated with chemotherapy. The intravenous administration of fosaprepitant allows for rapid absorption and onset of action, making it a convenient option for managing acute and delayed CINV in patients receiving highly emetogenic chemotherapy regimens.
• Describe the pharmacokinetic advantages of fosaprepitant compared to oral aprepitant.
  • Fosaprepitant is a prodrug that is designed to have improved bioavailability compared to the oral formulation of aprepitant. When administered intravenously, fosaprepitant is rapidly converted to the active aprepitant, allowing for more efficient absorption and higher drug concentrations in the body. This enhanced pharmacokinetic profile of fosaprepitant enables a convenient single-dose administration, whereas oral aprepitant typically requires multiple-day dosing regimens. The intravenous route of administration also ensures reliable delivery of the active drug, which is particularly important in the context of chemotherapy-induced nausea and vomiting, where oral medication may be challenging for patients to tolerate.
• Evaluate the clinical significance of fosaprepitant as an antiemetic medication in the management of chemotherapy-induced nausea and vomiting (CINV).
  • Fosaprepitant represents a significant advancement in the pharmacological management of CINV, a common and debilitating side effect of many chemotherapy regimens. By targeting the neurokinin-1 (NK1) receptor, the mechanism of action of fosaprepitant/aprepitant disrupts a key pathway involved in the vomiting reflex, providing effective prevention and control of both acute and delayed CINV. The intravenous formulation of fosaprepitant offers practical benefits, including improved bioavailability, rapid onset of action, and a convenient single-dose administration. These pharmacokinetic advantages translate to enhanced patient convenience and compliance, ultimately improving the overall quality of life for patients undergoing highly emetogenic chemotherapy. The clinical significance of fosaprepitant lies in its ability to provide comprehensive antiemetic protection, thereby enabling patients to better tolerate and adhere to their prescribed cancer treatment regimens.

Related terms

Aprepitant: The active metabolite of fosaprepitant, aprepitant is a selective NK1 receptor antagonist that blocks the binding of substance P, a neurotransmitter involved in the vomiting reflex.

Neurokinin-1 (NK1) Receptor: A G-protein coupled receptor found in the central and peripheral nervous system that binds substance P, a key neurotransmitter involved in the emetic (vomiting) response.

Prodrug: A pharmacologically inactive compound that is metabolized in the body to produce a pharmacologically active drug, often to improve absorption, distribution, or stability of the active drug.