Acyclovir: Uses, Dosage, Safety and Interactions

When working with acyclovir, a synthetic antiviral drug that stops herpes viruses from multiplying. Also known as Zovirax, it is the go‑to treatment for cold sores, genital herpes and shingles. Antiviral medication, a class of drugs that inhibit viral replication like acyclovir works by mimicking the building blocks of viral DNA, causing a chain reaction that halts the virus mid‑growth. This means the drug can shorten outbreaks, lessen pain and speed up healing. The drug is most effective when you start it at the first sign of a flare‑up – a classic “early‑treatment wins” rule that many patients overlook. Herpes simplex virus, the common cause of oral and genital sores is a prime target; without proper dosing, the virus can rebound and lead to more frequent recurrences. Acyclovir therefore requires the right dose, timing and awareness of kidney function, because the kidneys clear the drug and a slowdown can raise blood levels, increasing side‑effect risk.

Key Points to Know

Besides the classic oral tablets, acyclovir comes in topical cream, eye‑drop and IV forms. Topical versions are handy for early cold‑sores but don’t reach deep tissue, so oral tablets are still preferred for genital outbreaks. When you compare brand‑name Zovirax to generic options, the active ingredient and efficacy stay the same – the difference is price and packaging. For people who need once‑daily dosing, Valacyclovir, a prodrug that converts to acyclovir in the body offers a smoother schedule and often better adherence, though the cost can be higher. Dosage varies: typical adult regimens for shingles run 800 mg five times a day for 7‑10 days, while genital herpes suppression may be 500 mg daily. Adjustments are essential for children, the elderly, or anyone with reduced kidney function – a simple blood test can guide safe dosing. Watch out for drug interactions: co‑administration with probenecid can raise acyclovir levels, while concurrent use of nephrotoxic drugs like non‑steroidal anti‑inflammatories may increase kidney strain. Knowing these connections helps you avoid surprises such as nausea, headache or rare kidney irritation.

All this background sets the stage for the articles below. In the list you’ll find side‑by‑side comparisons of acyclovir with its cousins, dosing calculators, safety checklists and real‑world tips for managing herpes outbreaks. Whether you’re starting therapy, adjusting a regimen, or simply curious about how acyclovir fits into the broader antiviral landscape, the upcoming posts provide the practical details you need to make informed choices.