Idoxuridine is an anti-
herpesvirus
''Herpesviridae'' is a large family of DNA viruses that cause infections and certain diseases in animals, including humans. The members of this family are also known as herpesviruses. The family name is derived from the Greek word ''ἕρπειν ...
antiviral drug
Antiviral drugs are a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Unlike most antibiotics, antiviral drugs do n ...
.
It is a
nucleoside analogue
Nucleoside analogues are nucleosides which contain a nucleic acid analogue and a sugar. Nucleotide analogs are nucleotides which contain a nucleic acid analogue, a sugar, and a phosphate group with one to three phosphates.
Nucleoside and nucl ...
, a modified form of
deoxyuridine
Deoxyuridine (dU) is a compound and a nucleoside.It belongs to a class of compounds known as Pyrimidine 2'-deoxyribonucleosides and closely resembles the chemical composition of uridine but without the presence of the 2' hydroxyl group. Idoxuridine ...
, similar enough to be incorporated into viral
DNA replication
In molecular biology, DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. DNA replication occurs in all living organisms acting as the most essential part for biological inheritanc ...
, but the
iodine
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a vi ...
atom added to the
uracil
Uracil () (symbol U or Ura) is one of the four nucleobases in the nucleic acid RNA. The others are adenine (A), cytosine (C), and guanine (G). In RNA, uracil binds to adenine via two hydrogen bonds. In DNA, the uracil nucleobase is replaced by ...
component blocks
base pair
A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...
ing. It is used only topically due to cardiotoxicity. It was synthesized by
William Prusoff
William Herman Prusoff (June 25, 1920 – April 3, 2011) was a pharmacologist who was an early innovator in antiviral drugs, developing idoxuridine, the first antiviral agent approved by the FDA, in the 1950s, and co-developing (with Tai-shun ...
in the late 1950s.
Initially developed as an anticancer drug, idoxuridine became the first antiviral agent in 1962.
Clinical use
Idoxuridine is mainly used topically to treat
herpes simplex
Herpes simplex is a viral infection caused by the herpes simplex virus. Infections are categorized based on the part of the body infected.
Oral herpes involves the face or mouth. It may result in small blisters in groups often called cold ...
keratitis
Keratitis is a condition in which the eye's cornea, the clear dome on the front surface of the eye, becomes inflamed. The condition is often marked by moderate to intense pain and usually involves any of the following symptoms: pain, impaired e ...
.
[Goodman and Gilman's The Pharmacological Basis of Therapeutics. Edited by Gilman AG, Rall TW, Nies AS, Taylor P. McGraw-Hill. 8th ed. 1990.] Epithelial lesions, especially initial attacks presenting with a dendritic ulcer, are most responsive to therapy, while infection with stromal involvement are less responsive. Idoxuridine is ineffective against herpes simplex virus type 2 and
varicella-zoster
Varicella-zoster virus (VZV), also known as human herpesvirus 3 (HHV-3, HHV3) or ''Human alphaherpesvirus 3'' (taxonomically), is one of nine known herpes viruses that can infect humans. It causes chickenpox (varicella) commonly affecting chil ...
.
Side effects
Common side effects of the eye drops include irritation, blurred vision and
photophobia
Photophobia is a medical symptom of abnormal intolerance to visual perception of light. As a medical symptom photophobia is not a morbid fear or phobia, but an experience of discomfort or pain to the eyes due to light exposure or by presence of ...
.
[Drugs.com]
Idoxuridine ophthalmic
/ref> Cornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical power ...
l clouding and damage of the corneal epithelium may also occur.
Formulations and dosage
Idoxuridine is available as either a 0.5% ophthalmic ointment
A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes ...
or as a 0.1% ophthalmic solution
Solution may refer to:
* Solution (chemistry), a mixture where one substance is dissolved in another
* Solution (equation), in mathematics
** Numerical solution, in numerical analysis, approximate solutions within specified error bounds
* Soluti ...
. The dosage of the ointment is every 4 hours during day and once before bedtime. The dosage of the solution is 1 drop in the conjunctival sac hourly during the day and every 2 hours during the night until definitive improvement, then 1 drop every 2 hours during the day and every 4 hours during the night. Therapy is continued for 3–4 days after healing is complete, as demonstrated by fluorescein
Fluorescein is an organic compound and dye based on the xanthene tricyclic structural motif, formally belonging to triarylmethine dyes family. It is available as a dark orange/red powder slightly soluble in water and alcohol. It is widely used ...
staining.
Synthesis
See also
* Trifluridine
Trifluridine (also called trifluorothymidine; abbreviation TFT or FTD) is an anti-herpesvirus antiviral drug, used primarily on the eye. It was sold under the trade name Viroptic by Glaxo Wellcome, now merged into GlaxoSmithKline. The brand is n ...
* Acyclovir
Aciclovir (ACV), also known as acyclovir, is an antiviral medication. It is primarily used for the treatment of herpes simplex virus infections, chickenpox, and shingles. Other uses include prevention of cytomegalovirus infections following tran ...
* Foscarnet
Foscarnet (phosphonomethanoic acid), known by its brand name Foscavir, is an antiviral medication which is primarily used to treat viral infections involving the Herpesviridae family. It is classified as a pyrophosphate analog DNA polymerase inhib ...
References
Further reading
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{{Antivirals
Nucleosides
Pyrimidinediones
Organoiodides
Anti-herpes virus drugs
Hydroxymethyl compounds