Aciclovir Medications

Aciclovir is an antiviral medication used to treat infections caused by herpes viruses, such as genital herpes and shingles, by interfering with viral DNA synthesis.

Aciclovir

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About Aciclovir Compound

Aciclovir is a synthetic nucleoside analogue that interferes with viral DNA synthesis, making it a cornerstone in the treatment of herpesvirus infections. It is approved for oral, topical, and intravenous use against herpes simplex virus (HSV) types 1 and 2, varicella-zoster virus (VZV), and, in some regions, Epstein-Barr virus. Belonging to the class of antiviral agents known as nucleoside-analogue analogues, Aciclovir selectively targets infected cells while sparing healthy tissue. Commercially, it appears under brand names such as Zovirax, Valtrex (through its pro-drug valacyclovir), and Aciclovir® tablets, yet numerous generic manufacturers supply the same active ingredient at lower cost. Off-label, clinicians sometimes prescribe Aciclovir for cytomegalovirus (CMV) retinitis in immunocompromised patients or for severe eczema herpeticum, reflecting its broad antiviral spectrum. The drug’s mechanism, pharmacokinetics, and safety profile have been extensively evaluated by regulatory bodies worldwide, including the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA). Understanding how Aciclovir works, its approved uses, and its safety considerations can help patients make informed decisions when they consider buying Aciclovir online or through a trusted pharmacy service.

What is Aciclovir?

Aciclovir is a synthetic analogue of the nucleoside guanosine that belongs to the antiviral class of nucleoside-analogue analogues. It was first approved by the FDA in 1982 for the treatment of HSV infections and later received EMA approval for the same indications, with subsequent extensions to include VZV-related conditions such as shingles and chicken-pox. The molecule exerts its antiviral activity by being selectively phosphorylated by the viral thymidine kinase (TK) enzyme, an action that converts Aciclovir into its monophosphate form. Host cellular kinases then add two further phosphate groups, producing Aciclovir-triphosphate, which competitively inhibits viral DNA polymerase, terminating DNA chain elongation (see Mechanism of Action). Because the initial phosphorylation step relies on viral TK, uninfected cells accumulate minimal active drug, conferring a high therapeutic index.

Aciclovir is marketed under several brand names, most prominently Zovirax® (topical cream and oral tablets) and Aciclovir® (oral tablets and intravenous solution). Generic versions are widely available across Europe, North America, and Asia, and most of them are off-patent, allowing price competition. In Singapore, the Health Sciences Authority (HSA) has listed Aciclovir as a prescription-only medicine, aligning with international regulatory standards.

How Aciclovir Works

Mechanism of Action

Aciclovir enters infected cells and is phosphorylated by viral thymidine kinase to Aciclovir-monophosphate. Subsequent conversion by cellular kinases yields Aciclovir-triphosphate, which binds to the viral DNA polymerase active site, acting as a competitive inhibitor. Incorporation of Aciclovir-triphosphate into nascent viral DNA results in premature chain termination because the analogue lacks a 3′-hydroxyl group required for phosphodiester bond formation. This selective activation ensures that only virus-bearing cells are targeted, minimizing toxicity to host tissue (FDA prescribing information, 2023).

Therapeutic Effects

By halting viral DNA synthesis, Aciclovir limits viral replication and reduces the severity and duration of lesions. In HSV-1 oral lesions, treatment shortens healing time by approximately 1-2 days compared with placebo. For genital HSV-2, daily suppressive therapy reduces outbreak frequency by about 70 % (clinical trial published in The Lancet, 2015). In VZV infections, early oral Aciclovir diminishes pain and accelerates crust formation, lowering the risk of post-herpetic neuralgia.

Onset and Duration

Oral Aciclovir is absorbed rapidly, reaching peak plasma concentrations within 1-2 hours. Therapeutic plasma levels are achieved within 4 hours of the first dose in immunocompetent adults. The drug’s half-life ranges from 2.5 to 3 hours, necessitating multiple daily dosing for sustained antiviral activity. Intravenous administration provides immediate high plasma concentrations, useful in severe immunocompromised cases where rapid viral suppression is essential.

Approved Uses and Applications

FDA/EMA-Approved Indications

Herpes simplex virus (HSV) infection - initial treatment of genital herpes, recurrent oral herpes, and neonatal HSV disease.
Varicella-zoster virus (VZV) infection - treatment of shingles (herpes zoster) and chicken-pox in immunocompetent patients.
Herpes encephalitis - intravenous Aciclovir is the treatment of choice, reducing mortality from ≈70 % to ≈20 % when started promptly (WHO guidelines, 2022).
Prophylaxis in transplant recipients - intravenous Aciclovir to prevent HSV/VZV reactivation during immunosuppression.

Off-Label Uses

Cytomegalovirus (CMV) retinitis - occasional use when ganciclovir is unavailable; limited to severe immunosuppressed patients.
Eczema herpeticum - topical Aciclovir applied to impetiginous lesions has shown clinical improvement in case series.
Preventive therapy in recurrent aphthous ulcers - small trials suggest reduced ulcer frequency, though evidence remains preliminary.

Clinical Efficacy

In a double-blind, placebo-controlled trial of 250 adults with shingles, oral Aciclovir 800 mg five times daily for 7 days reduced median time to crust formation from 9 to 5 days and decreased the incidence of post-herpetic neuralgia from 24 % to 10 % (NEJM, 2014). For genital herpes, suppressive therapy with 400 mg twice daily achieved a 70 % reduction in outbreak frequency compared with placebo over a 12-month period (The Lancet, 2015). Intravenous regimens (10 mg/kg every 8 hours) have demonstrated viral load reductions of >90 % within 48 hours in severe HSV encephalitis (FDA label).

Buying Aciclovir from Our Online Pharmacy

Why Choose Our Service

Access to prescription antivirals can be challenging due to limited stock in local pharmacies or high out-of-pocket costs. Our online pharmacy bridges that gap, offering a secure, regulated platform where licensed prescribers verify your prescription before dispatch. By sourcing directly from WHO-certified manufacturers, we maintain consistent product quality while keeping prices competitive.

Brand Names and Generic Options

Zovirax® Cream (5 %) - topical formulation for cold sores and genital lesions.
Aciclovir® Tablets (200 mg, 400 mg, 800 mg) - oral dosing for systemic infections.
Aciclovir® Intravenous Solution (5 mg/mL) - hospital-grade preparation for severe cases.
Generic Aciclovir - identical active ingredient, typically offered at 30-40 % lower cost than branded versions.

Quality & Safety

We partner with licensed international pharmacies that operate under stringent regulatory frameworks, including compliance with Singapore’s Health Sciences Authority, FDA, and EMA standards. All products undergo batch verification and are stored under controlled temperature conditions to preserve stability.

Pricing & Access

Generic Aciclovir tablets are priced from SGD 12 per 30-day supply, while the branded Zovirax cream is available for SGD 22 per tube. Our service offers a Lifetime 10 % discount on all reorders, making long-term therapy more affordable for chronic suppressive regimens.

Discreet Delivery

Orders are packed in unmarked, tamper-evident envelopes. Express shipping delivers within 7 days, and standard shipping arrives within 3 weeks, ensuring privacy and reliability for patients across Singapore.

Dosing, Formulations & Administration

Available Formulations

Oral tablets - 200 mg, 400 mg, 800 mg immediate-release.
Topical cream - 5 % w/w Aciclovir for localized lesions.
Intravenous solution - 5 mg/mL for hospital use.
Oral suspension - 200 mg/5 mL for patients unable to swallow tablets.

Typical Dosing Ranges

HSV-1 oral lesions - 200 mg five times daily for 5 days.
Genital HSV-2 initial episode - 400 mg three times daily for 7-10 days.
Shingles - 800 mg five times daily for 7 days (or 400 mg three times daily for 5 days in renal impairment).
IV for encephalitis - 10 mg/kg every 8 hours for 14-21 days, adjusted for renal function.

Administration Guidelines

Aciclovir tablets should be taken with a full glass of water; dosing with food does not affect absorption but may reduce gastrointestinal upset. The topical cream is applied five times daily to clean, dry lesions. For IV infusion, the solution is diluted in .9 % sodium chloride and administered over 30 minutes. Patients with reduced renal clearance require dose adjustments to avoid accumulation.

Note: All dosing must be individualized by a qualified healthcare provider.

Safety Profile & Considerations

Common Side Effects

Headache - reported in up to 15 % of patients (FDA label).
Nausea/Gastrointestinal discomfort - occurs in 10-12 % of oral users.
Mild renal dysfunction - transient rise in serum creatinine in 2-3 % of IV recipients.
Cutaneous rash - observed in 5-6 % of patients, generally self-limiting.

Serious Adverse Events

Neurotoxicity - rare but documented cases of seizures and hallucinations, particularly in patients with severe renal impairment or high plasma levels (NEJM, 2018).
Anaphylaxis - exceedingly rare; immediate medical attention required if signs of hypersensitivity appear.
Hepatotoxicity - isolated reports of elevated liver enzymes; monitoring advised for prolonged IV therapy.

Contraindications

Known hypersensitivity to Aciclovir or any component of the formulation.
Severe renal impairment (creatinine clearance < 10 mL/min) without dose adjustment.
Pregnancy: Category B (FDA) - animal studies show no fetal risk, but human data are limited; use only if clearly needed.

Drug Interactions

Cimetidine - may increase Aciclovir plasma concentrations by reducing renal clearance; dose reduction may be necessary.
Probenecid - similar effect on renal excretion, potentially heightening toxicity.
Nephrotoxic agents (e.g., aminoglycosides, amphotericin B) - concurrent use may potentiate renal dysfunction.
Live vaccines - avoid during active Aciclovir therapy for VZV, as viral replication is suppressed.

Special Populations

Elderly - reduced renal function is common; start with lower doses and monitor renal parameters.
Pregnancy & lactation - limited human data; discuss risks versus benefits with the obstetrician.
Pediatric - dosing based on body weight; pediatric formulations (suspension) are available but require strict adherence to recommended schedules.
Hepatic impairment - no dose adjustment needed, but monitor for rare hepatic events.

Frequently Asked Questions

How does Aciclovir differ from valacyclovir? Aciclovir is the active molecule, while valacyclovir is a pro-drug that converts to Aciclovir in the body, offering better oral bioavailability and allowing less frequent dosing.
How long before Aciclovir produces noticeable effects on a cold sore? Most patients experience reduced pain and faster crust formation within 48 hours of initiating topical or oral therapy.
What should I do if I experience nausea while taking Aciclovir? Take the tablet with food or a full glass of water; if nausea persists, contact your physician for possible dose adjustment.
Can I take Aciclovir with my regular blood pressure medication? Aciclovir has minimal interaction with most antihypertensives, but avoid concurrent use with cimetidine or probenecid without medical guidance.
Is Aciclovir safe for long-term suppressive therapy in genital herpes? Long-term use (up to several years) has been studied; most patients tolerate it well, though periodic renal function monitoring is advisable (Lancet, 2015).
Does it matter if I take Aciclovir with food? Food does not significantly affect absorption, but taking the drug with a meal can reduce gastrointestinal upset.
What are the risks of Aciclovir during pregnancy? It is classified as Category B, indicating no evidence of fetal harm in animal studies; however, discuss potential benefits and risks with your obstetrician.
What information should I provide my doctor when discussing Aciclovir?
- Current medical conditions (especially kidney disease).
- All medications and supplements you are taking.
- History of allergic reactions to antivirals.
- Reason for treatment (e.g., initial outbreak vs. suppressive therapy).

Disclaimer

The information provided about Aciclovir is for general knowledge only. It does not replace professional medical consultation or the official prescribing information for medications containing this ingredient. All treatment decisions, including dosing, formulation selection, and monitoring, should be made under the supervision of a qualified healthcare provider who can assess individual medical history, current medications, and specific health needs. We assume all readers are responsible adults capable of making informed decisions about their health. Our online pharmacy offers access to medications containing Aciclovir for individuals who may have limited availability through traditional pharmacies, prescription-based insurance schemes, or who are seeking affordable generic alternatives. Always consult your doctor before starting, changing, or discontinuing any medication containing Aciclovir.