Idoxuridin Chemische Eigenschaften,Einsatz,Produktion Methoden
R-S?tze Betriebsanweisung:
R45:Kann Krebs erzeugen.
R46:Kann vererbbare Sch?den verursachen.
R61:Kann das Kind im Mutterleib sch?digen.
R40:Verdacht auf krebserzeugende Wirkung.
S-S?tze Betriebsanweisung:
S53:Exposition vermeiden - vor Gebrauch besondere Anweisungen einholen.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn m?glich, dieses Etikett vorzeigen).
S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
S22:Staub nicht einatmen.
Chemische Eigenschaften
Crystalline Solid
Verwenden
Idoxuridine is an antiviral agent effective against herpes-simplex infections; in ophthalmie eyedrops, ointments, and solutions.
Indications
Idoxuridine (Herplex) is a water-soluble iodinated derivative
of deoxyuridine that inhibits several DNA viruses
including HSV, VZV, vaccinia, and polyoma virus. The
triphosphorylated metabolite of idoxuridine inhibits
both viral and cellular DNA synthesis and is also incorporated
into DNA. Such modified DNA is susceptible to
strand breakage and causes aberrant viral protein synthesis.
Because of its significant host cytotoxicity, idoxuridine
cannot be used to treat systemic viral infections. The
development of resistance to this drug is common.
Definition
ChEBI: A pyrimidine 2'-deoxyribonucleoside compound having 5-iodouracil as the nucleobase; used as an antiviral agent.
Pharmazeutische Anwendungen
A halogenated pyrimidine analog originally synthesized as an
anticancer agent. Formulated in dimethylsulfoxide for topical
application and as a solution for ophthalmic use.
Activity is largely limited to DNA viruses, primarily HSV-1,
HSV-2 and VZV. HSV-1 plaque formation in BHK 21 cells
is sensitive to 6.25–25 mg/L; type 2 microplaques required
62.5–125 mg/L. RNA viruses are not affected, with the exception
of oncogenic RNA viruses such as Rous sarcoma virus.
Drug resistance is easily generated in vitro, and may be an
obstacle to treatment. However, there is little or no crossresistance
with newer nucleoside analogs.
It is poorly soluble in water, and aqueous solutions are
ineffective against infections other than those localized to the
eye. In animals, therapeutic levels are achieved in the cornea
within 30 min of ophthalmic application and persist for 4 h.
Penetration is otherwise poor, with only the biologically inactive
dehalogenated metabolite uracil entering the eye.
The drug is too toxic for systemic administration. Contact
dermatitis, punctate epithelial keratopathy, follicular conjunctivitis,
ptosis, stenosis and occlusion of the puncta and keratinization
of the lid margins occur in up to 14% of those
receiving ophthalmic preparations.
It is used in herpes keratitis, but has largely been superseded
by trifluridine or aciclovir.
Mechanism of action
Idoxuridine is a nucleoside containing a halogenated pyrimidine and is an analogue of thymidine. It
acts as an antiviral agent against DNA viruses by interfering with their replication based on the similarity
of structure between thymidine and idoxuridine. Idoxuridine is first phosphorylated by the host cell virusencoded enzyme thymidine kinase to an active triphosphate form. The phosphorylated drug inhibits
cellular DNA polymerase to a lesser extent than HSV DNA polymerase, which is necessary for the
synthesis of viral DNA. The triphosphate form of the drug is then incorporated during viral nucleic acid
synthesis by a false pairing system that replaces thymidine. When transcription occurs, faulty viral
proteins are formed, resulting in defective viral particles.
Clinical Use
The only FDA-approved use of idoxuridine is in the
treatment of herpes simplex infections of the eyelid, conjunctiva conjunctiva,
and cornea. It is most effective against surface
infections because it has little ability to penetrate the tissues
of the eye. intravenous idoxuridine was designated
an orphan drug for the treatment of soft tissue sarcoma.
Nebenwirkungen
Idoxuridine may cause local irritation, mild edema, itching,
and photophobia. Corneal clouding and small punctate
defects in the corneal epithelium have been reported.
Allergic reactions are rare.
Sicherheitsprofil
Moderately toxic by
intraperitoneal route. Experimental
teratogenic and reproductive effects.
Questionable carcinogen with experimental
carcinogenic data. Human mutation data
reported. When heated to decomposition it
emits very toxic fumes of Iand NOx.
Stoffwechsel
Idoxuridine is metabolized rapidly in the body to iodouracil, uracil, and iodide. Metabolites are excreted in the urine.
Idoxuridin Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
