Researchers Evaluate the Safety and Efficacy of Brivudine as Oral Shingles Treatment

New study findings assessed the efficacy and safety of brivudine (BVDU, Zostex), a 5′-halogenated thymidine nucleoside analogue that is a licensed treatment for herpes zoster (HZ), which has inconclusive safety data.^1,2

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The varicella zoster virus (VZV) is an infection known to cause chicken pox and can reactivate as shingles after the initial infection. VZV remains dormant for many years, but when reactivated it travels along sensory nerve fibers, resulting in shingles infection. The virus causes a development of painful, blistering rashes in a dermatomal distribution.³ Study authors noted that the prevalence of HZ is about 0.2 to 2% in the general population.¹

“Timely antiviral therapy against VZV is crucial in HZ treatment, that can effectively reduce formation of new lesions, accelerate healing and lower risk of and postherpetic neuralgia,” said the study authors.¹

Common antiviral treatments used for shingles includes valaciclovir, acyclovir, and famciclovir. Differing from these treatment options, brivudine has high bioavailability (90%) and high specificity against shingles. Previously conducted studies suggested that brivudine is more effective in treating pediatric patients compared to the antiviral drugs, displaying better efficacy. However, further studies did not demonstrate significant differences in improvements of pain and vesicle severity with brivudine compared with other antiviral drugs, according to study authors.¹

To explore the inconclusive data, researchers conducted a meta-analysis to assess the clinical efficacy, safety, and postherpetic neuralgia (PHN) complications among individuals treated with brivudine compared with non-brivudine treatment. The study authors noted that data of randomized controlled trials (RCTS) were acquired from 7 databases (PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, China Science Journal Database, and WanFang Database). Among the 7 RCTS, a total of 4171 patients were included—2095 patients in the experimental group and 2076 in the control group, evaluating the treatment of HZ with brivudine.¹

The study authors noted that inclusion criteria included “(1) randomized controlled clinical trials; (2) patients were diagnosed with herpes zoster; (3) patients in the observation group were treated with brivudine alone, while those in the control group were treated with medications other than brivudine; and (4) at least one of following indicators was evaluated: efficacy, adverse reaction, safety, blister time, pain relief time, incidence of PHN,” according to the study authors.¹

Individuals included in the observation group were given an oral dose of 125 mg of brivudine, daily for 1 week, as individuals in 1 observation group were given an oral dose of 125 mg of brivudine every 6 hours for 5 days. Following, 2 control groups were treated with an oral dose of valacyclovir, as individuals in the remainder 5 groups were treated intravenously or orally treated with acyclovir.¹

The results displayed brivudine had better efficacy for treating HZ and shorter recovery time, compared to treatment with acyclovir and valaciclovir. Additionally, brivudine displayed advancements in clinical efficacy and prevention of PHN occurrence, while maintaining the safety in shingles treatment. Brivudine also was able to effectively lower PHN compared to the antiviral treatments. However, the results confirmed that there were no significant differences in adverse reactions among all 3 treatments, according to study authors.¹

The findings suggest that brivudine is more effective in treating HZ and does not increase the risk of adverse reactions. However, the study authors noted that additional studies that include a larger group of participants needs to be conducted to further assess its safety and efficacy for shingles treatment.¹

REFERENCES

1. Chen J, Lei D, Cao P, He J, Zhang L. Efficacy and safety of brivudine for the treatment of herpes zoster: a systematic review and meta-analysis. J Dermatolog Treat. 2024;35(1):2355256. doi:10.1080/09546634.2024.2355256

2. Antivirals against DNA viruses (hepatitis B and the herpes viruses). Science Direct. News release. October 2004. Accessed November 8, 2024. https://www.sciencedirect.com/science/article/abs/pii/S1471489204001274

3. Ferruggia K. Study: Shingles Reactivation Could Occur in Rare Cases Following RZV. Pharmacy Times. September 20, 2024. Accessed November 8, 2024. https://www.pharmacytimes.com/view/study-shingles-reactivation-could-occur-in-rare-cases-following-rzv