idoxuridine

Action and Spectrum

Actions and Spectrum: 

Action: 

Nucleoside Analog: idoxuridine is structurally like the natural nucleoside deoxythymidine (dT), which is one of the building blocks of DNA. However, it contains a halogenated uracil base instead of thymine. 

Incorporation into Viral DNA: When the virus-infected cells administer idoxuridine, it can be taken up. Inside these cells, the drug is phosphorylated and converted into its active form, idoxuridine triphosphate. 

Spectrum: 

Herpes Simplex Virus: idoxuridine is mainly used to treat herpes simplex keratitis, an eye infection caused by herpes simplex virus. 

Varicella-Zoster Virus: idoxuridine has some activity against the varicella-zoster virus, which causes chickenpox and shingles, although it is not commonly used for these infections. 

Drug Interaction

Adverse Reaction

Frequency not defined  

Eye inflammation 

Pain 

Irritation 

Corneal damage 

Conjunctivitis 

pruritus 

Black Box Warning

Black Box Warning:  

None

Contraindication / Caution

Contraindication/Caution:  

Hypersensitivity: idoxuridine should not be used in individuals who have a known hypersensitivity or allergy to idoxuridine or any of its components. 

Pregnancy: The safety of idoxuridine use during pregnancy has not been well established. During pregnancy, it should only be employed when the potential benefits for the pregnant woman are greater than the potential risks to the developing fetus, and it should be administered under the vigilant guidance of a qualified healthcare provider. 

Breastfeeding: It is not recommended to use idoxuridine while breastfeeding. If necessary, breastfeeding should be discontinued during treatment. 

Children: idoxuridine is generally not recommended for use in infants and young children, as safety and efficacy have not been well established in this age group. 

Concurrent Use of Other Eye Medications: Care should be taken when using idoxuridine alongside other ophthalmic medications, as drug interactions may occur. Following your healthcare provider’s instructions regarding using multiple eye medications is essential. 

Pregnancy / Lactation

Pregnancy warnings:     

Pregnancy category: N/A 

Lactation: Excreted into human milk is unknown 

Pregnancy Categories:         

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester. 

<b>Category B: There were a lack of studies on pregnant women and no evidence of risk to the fetus in animal experiments.   

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.   

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: There is no data available for the drug under this category

Pharmacology

Pharmacology:  

idoxuridine is an antiviral medication primarily used in herpes simplex viruses. 

Pharmacodynamics:  

idoxuridine works by inhibiting the replication of viral DNA. It is structurally like the natural nucleoside deoxyuridine, which is a building block of DNA. When idoxuridine is incorporated into the viral DNA during replication, it can cause chain termination and prevent further elongation of the viral DNA strand. This disrupts the viral replication cycle and reduces the spread of the virus.  

Pharmacokinetics: 

Absorption 

idoxuridine is primarily administered topically as an ophthalmic solution or cream for the treatment of eye infections or skin lesions. It can also be administered intravenously in some cases. 

Distribution 

After topical application, idoxuridine can penetrate the cornea and reach therapeutic concentrations in the eye. It does not have a significant systemic distribution when used topically. 

Metabolism 

idoxuridine is metabolized in the body, primarily in the liver. It undergoes phosphorylation to its active form, idoxuridine triphosphate. 

Excretion and Elimination 

The metabolites of idoxuridine are primarily eliminated through renal excretion. 

Adminstartion

Administration:  

Before administering idoxuridine or any other eye medication, make sure to wash your hands thoroughly with soap and water. idoxuridine is usually supplied as an ophthalmic solution or ointment.

If it is in the form of a solution, make sure the bottle is properly sealed and shake it gently to mix the medication. If it is in the form of an ointment, ensure that the tube is sealed properly. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: idoxuridine 

Why do we use idoxuridine?  

idoxuridine is most employed in the treatment of herpetic keratitis, which is an eye infection caused by the herpes simplex virus (HSV). In addition to herpetic keratitis, idoxuridine may be used to treat other viral eye infections, including those caused by the varicella-zoster virus (VZV) and vaccinia virus. 

idoxuridine can be prescribed for individuals who experience recurrent or persistent viral eye infections, especially if they are not responding well to other treatments.