Raltitrexed

Toxicity

Side effects include pale skin, troubled breathing, unusual bleeding or bruising, unusual tiredness or weakness, black, tarry stools, chest pain, chills, cough, fever, painful or difficult urination, shortness of breath, sore throat, sores, ulcers, or white spots on lips or in mouth, swollen glands, increase in bowel movements, loose stools, soft stools.

Description

Tomudex was launched in Ireland, France, Luxembourg and the UK for advanced colorectal cancer and it was prepared in a convergent manner (6 steps) from diethyl L-glutamate and 6-bromomethyi-2-methyl-quinazolin4(3H)-one. Tomudex is a highly selective inhibitor of thymidylate synthase (TS), the key enzyme in the biochemical conversion of dUMP to dTMP. It enters the cell via the reduced folatefmethotrexate cell membrane carrier and is converted to the polyglutamate species by folylpolyglutamate synthase within 4h where it then binds to the folate substrate site of TS. Clinically, it had a 29% response rate in patients with advanced colorectal cancer. It is water soluble, can be administered as a single dose every three weeks and had no hepto- or nephrotoxicity.

Chemical properties

Yellow Crystalline Powder

Originator

Zeneca (UK)

The Uses of Raltitrexed

Folate-based inhibitor of thymidylate synthase; rapidly and extensively metabolized to its more potent polyglutamate derivatives. Antineoplastic

What are the applications of Application

Raltitrexed is an inhibitor of thymidylate synthase and DHFR

Indications

For the treatment of malignant neoplasm of colon and rectum

Background

Raltitrexed (brand name Tomudex?) is a chemotherapy drug manufactured AstraZeneca Company, is an antimetabolite used in chemotherapy. It is an inhibitor of thymidylate synthase.

Definition

ChEBI: ICI D1694 is a N-acyl-amino acid.

brand name

Tomudex (Zeneca).

Biochem/physiol Actions

Raltitrexed is a folate-based inhibitor of thymidylate synthase (TS) that is rapidly and extensively metabolized to its more potent polyglutamate derivatives. By inhibiting the formation of precursor pyrimidine nucleotides, raltitrexed prevents the formation of DNA and RNA, which are required for the growth and survival of both normal cells and cancer cells.

Pharmacokinetics

Raltitrexed belongs to a group of medicines known as antimetabolites. It is used to treat cancer of the colon and rectum. It may also be used to treat other kinds of cancer, as determined by your doctor. Raltitrexed blocks an enzyme needed by the cell to live. This interferes with the growth of cancer cells, which are eventually destroyed. Since the growth of normal body cells may also be affected by raltitrexed, other effects will also occur. Some of these may be serious and must be reported to your doctor. Other effects, like hair loss, may not be serious but may cause concern.

Clinical Use

Treatment of colorectal cancer when fluorouracil and folinic acid cannot be used

Drug interactions

Potentially hazardous interactions with other drugs
Antipsychotics: avoid with clozapine, increased risk of agranulocytosis.
Folic and folinic acid: impairs cytotoxic action - avoid.

Metabolism

Raltitrexed is transported into cells via a reduced folate carrier. Inside the cell it is extensively polyglutamated by the enzyme folyl polyglutamate synthetase to polyglutamate forms.

Metabolism

Raltitrexed is actively transported into cells and metabolised to active polyglutamate forms.
The remainder of a dose is not metabolised and is excreted unchanged, about 50% of a dose appearing in the urine, and about 15% in the faeces.