Acyclovir – Everything You Need to Know

When working with Acyclovir, a synthetic antiviral that blocks DNA replication of certain herpes viruses. Also known as Zovirax, it is the go‑to drug for cold sores, genital herpes, and shingles. Herpes Simplex Virus, the virus behind oral and genital lesions and Varicella Zoster Virus, the cause of chickenpox and shingles are the primary targets. Knowing how Acyclovir interacts with these viruses lets you use it safely and effectively.

At its core, Acyclovir is a nucleoside analog; once inside infected cells, viral enzymes convert it into a toxic triphosphate that halts viral DNA synthesis. This mechanism means the drug works best when started early, especially during the first 48 hours of a cold‑sore flare‑up. Because it targets virus‑specific enzymes, healthy cells are largely spared, which explains the relatively mild side‑effect profile. However, resistance can emerge, particularly in immunocompromised patients where the virus mutates the thymidine kinase enzyme needed for activation.

Key Uses, Dosage Forms, and Safety Tips

Typical dosage forms include oral tablets, topical creams, and intravenous injections. For recurrent oral herpes, a common regimen is 200 mg five times daily for five days; for genital lesions, 400 mg three times daily for seven to ten days is standard. Shingles treatment usually involves 800 mg five times daily for seven days. Topical creams, usually 5 % Acyclovir, are applied five times a day for ten days to speed healing of superficial lesions. Adjustments are needed for kidney impairment—lower doses or extended intervals help avoid accumulation.

Side effects are generally mild: headache, nausea, and occasional dizziness are the most reported. Rarely, high‑dose IV therapy can cause nephrotoxicity, so hydration and monitoring are essential. Pregnant women can use Acyclovir when benefits outweigh risks, as category B studies show no major teratogenic effects. Breast‑feeding mothers should weigh infant exposure against maternal need, but short courses are usually acceptable.

Understanding drug interactions is also crucial. Acyclovir’s renal clearance can be reduced by probenecid, leading to higher plasma levels. Concurrent use of nephrotoxic agents like aminoglycosides may increase kidney strain. Always inform your pharmacist about other meds, especially over‑the‑counter supplements.

Finally, patient education makes a big difference. Remind readers to start treatment at the first sign of tingling or itching, store the medication at room temperature away from moisture, and complete the full course even if symptoms improve. Proper adherence minimizes viral shedding and limits resistance development.

Below you’ll find a curated selection of articles covering everything from dosage comparisons to safety guides, all centered around Acyclovir and its role in managing herpes‑related conditions. Dive in to get practical tips, detailed product reviews, and up‑to‑date guidance that will help you make informed decisions about this essential antiviral.