AMIFOSTINE injection powder lyophilized for solution

Land: USA

Språk: engelsk

Kilde: NLM (National Library of Medicine)

Aktiv ingrediens:

AMIFOSTINE (UNII: M487QF2F4V) (AMIFOSTINE ANHYDROUS - UNII:ILA426L95O)

Tilgjengelig fra:

Bedford Laboratories

INN (International Name):

AMIFOSTINE

Sammensetning:

AMIFOSTINE ANHYDROUS 500 mg in 10 mL

Resept typen:

PRESCRIPTION DRUG

Autorisasjon status:

New Drug Application

Preparatomtale

AMIFOSTINE- AMIFOSTINE INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION
BEDFORD LABORATORIES
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AMIFOSTINE FOR INJECTION
RX ONLY
DESCRIPTION
Amifostine for Injection is an organic thiophosphate cytoprotective
agent known chemically as 2-[(3-
aminopropyl)amino]ethanethiol dihydrogen phosphate (ester) and has the
following structural formula:
H N(CH )
NH(CH )
S-PO H
Amifostine is a white crystalline powder which is freely soluble in
water. Its empirical formula is
C H N O PS and it has a molecular weight of 214.22.
Amifostine for Injection is the trihydrate form of amifostine and is
supplied as a sterile lyophilized
powder requiring reconstitution for intravenous infusion. Each
single-use 10 mL vial contains 500 mg
of amifostine on the anhydrous basis.
CLINICAL PHARMACOLOGY
Amifostine is a prodrug that is dephosphorylated by alkaline
phosphatase in tissues to a
pharmacologically active free thiol metabolite. This metabolite is
believed to be responsible for the
reduction of the cumulative renal toxicity of cisplatin and for the
reduction of the toxic effects of
radiation on normal oral tissues. The ability of amifostine to
differentially protect normal tissues is
attributed to the higher capillary alkaline phosphatase activity,
higher pH and better vascularity of
normal tissues relative to tumor tissue, which results in a more rapid
generation of the active thiol
metabolite as well as a higher rate constant for uptake into cells.
The higher concentration of the thiol
metabolite in normal tissues is available to bind to, and thereby
detoxify, reactive metabolites of
cisplatin. This thiol metabolite can also scavenge reactive oxygen
species generated by exposure to
either cisplatin or radiation.
PHARMACOKINETICS
Clinical pharmacokinetic studies show that amifostine is rapidly
cleared from the plasma with a
distribution half-life of < 1 minute and an elimination half-life of
approximately 8 minutes. Less than
10% of amifostine remains in the plasma 6 minutes after drug
administration. Amifostine is rapidly
metabol