Amifostine is a cytoprotective drug which is used for minimizing the side effects of radiation treatment as well as certain chemotherapic agents. The drug is also referred to as an antineoplastic adjunct and a chemoprotectant.

Amifostine Identification

CAS Number: 20537-88-6

PubChem Compound ID: CID 2141

PubChem Substance ID: 46505305

ChemSpider Reference Number: 2056

ChEBI: CHEBI:2636

PharmGKB: PA448365

ATC code: V03AF05

DrugBank: APRD00021

KEGG Compound ID: C06819

UNII: M487QF2F4V

ChEMBL: CHEMBL1006

Drug Product Database: 2218054

InChI Identifier: InChI=1S/C5H15N2O3PS/c6-2-1-3-7-4-5-12-11(8,9)10/h7H,1-6H2,(H2,8,9,10)

InChIKey: InChIKey=JKOQGQFVAUAYPM-UHFFFAOYSA-N

Amifostine IUPAC Name

The IUPAC Name for Amifostine is

({2-[(3-aminopropyl)amino]ethyl}sulfanyl)phosphonic acid.

Amifostine Chemical Formula

The chemical formula for Amifostine is C₅H₁₅N₂O₃PS.

Picture 1 – Amifostine

Amifostine Properties

Molar Mass

The molar mass of Amifostine is 214.224 g/mol.

Monoisotopic Mass

The monoisotopic mass of Amifostine is 214.054099558 u (unified atomic mass units).

Half-life

This drug has a half-life of 8 minutes.

Amifostine Uses

Amifostine is used to reduce the symptoms of neutropenia-related infection and fever caused by DNA-binding chemotherapeutic agents such as platinum-containing agents like cisplatin and alkylating agents like cyclophosphamide.

This drug is used to minimize the cumulative nephrotoxicity caused by platinum-containing agents.

Amifostine is prescribed for women having advanced ovarian cancer and receiving frequent doses of cisplatin. In these cases, amifostine helps to minimize the harmful side effects of chemotherapy.

Amifostine is also administered to patients undergoing radiation treatment for head and neck cancer to relieve the symptoms of xerostomia or dryness of mouth.

How the Amifostine drug is administered

Amifostine can be described as an organic thiophosphate prodrug. It goes through hydrolysis inside the body by alkaline phosphatase to produce WR-1065, an active cytoprotective thiol metabolite. The higher pH, high activity of alkaline phosphatase as well as the tendency of normal tissues going through vascular permeation are believed to be the causes behind non-malignant tissues being selectively protected.

Amifostine is given intravenously almost half an hour before the beginning of radiation therapy or chemotherapy.

Before the administration of Amifostine, the patient should drink plenty of water and fluids. Patients receive this drug either facing up or lying down. The patient’s blood pressure is frequently monitored during the entire procedure.

Along with Amifostine, anti-nausea drug may also be administered to the patient.

The amount or dosage of Amifostine received by the patient depends on several factors such as the height and weight of the patient, the general health profile as well as the health condition that is being treated.

Amifostine Working Principle

Amifostine is administered with some types of chemotherapy. Its main aim is to reduce the side effects of chemotherapy and provide protection to the body. Amifostine do not eliminate the side effects completely but provide protection from some potentially dangerous side effects. Since this drug also has some side effects of its own, it is used sparingly and only in cases where the health benefits are greater than the side effects.

Inside the body, Amifostine is broken down into some other chemicals which act on the harmful constituents of chemotherapy drugs. The drug also acts as a scavenger and binds with potentially harmful components called free radicals that are produced by tissues exposed to cisplatin.

Amifostine also has certain other effects on the body which includes the triggering of cellular hypoxia, prevention of apoptosis, acceleration of DNA repair, modifying enzyme activity and altering genetic expression.

Amifostine Side Effects

There are certain general side effects of the Amifostine drug. These include:

• Hypocalcemia
• Flushing (feeling of warmth)
• Nausea
• Diarrhea
• Vomiting
• Chills
• Sneezing
• Lightheadedness or dizziness
• Somnolence
• Fever
• Hiccoughs

Amifostine can also cause some serious side effects. These are

• Shortness of breath
• Hypotension
• Hives
• Skin rash
• Stevens-Johnson syndrome
• Erythema multiforme
• Toxic epidermal necrolysis
• Anaphylaxis
• Erythroderma
• Immune hypersensitivity syndrome
• Loss of consciousness
• Seizures
• Fainting
• Chest tightness
• Swelling of the throat

Some important points regarding the side effects of Amifostine

Here are some important facts about the side effects caused by Amifostine:

• Majority of the people do not suffer from all the side effects that are listed here.
• The duration and intensity of the side effects are often predictable.
• The side effects of Amifostine are reversible in most cases and will heal completely after completion of treatment.
• There are many ways to prevent or minimize the side effects.
• There are no direct correlations between the intensity of the side effects and medical effectiveness of Amifostine.

Amifostine Contraindications

Hypersensitivity to Amifostine as well as aminothiol compounds such as WR-1065 are considered to be contraindicative symptoms against Amifostine.

Amifostine Marketing

Amifostine is marketed by the pharmaceutical company MedImmune under the name Ethyol.

References
1. http://www.chemocare.com/bio/amifostine.asp
2. http://www.nlm.nih.gov/medlineplus/druginfo/meds/a696014.html
3. http://www.drugbank.ca/drugs/DB01143
4. http://en.wikipedia.org/wiki/Amifostine