Aciclovir is a nucleoside analogue antiviral medication specifically designed to manage infections caused by the herpes simplex virus (HSV) and varicella-zoster virus (VZV). It functions by inhibiting viral DNA replication, thereby reducing the severity and duration of outbreaks. Clinically proven and widely prescribed, aciclovir is available in oral, topical, and intravenous formulations to suit varying patient needs and clinical scenarios. Its targeted mechanism ensures high efficacy with a well-established safety profile, making it a first-line choice for both episodic and suppressive therapy.

Features

• Active ingredient: Aciclovir
• Available forms: Tablets, cream, ointment, intravenous injection
• Mechanism: Selective inhibition of viral DNA polymerase
• Bioavailability: Approximately 15–30% (oral)
• Half-life: 2.5–3.3 hours in adults with normal renal function
• Pregnancy category: B

Benefits

• Reduces healing time for active herpes lesions
• Decreases frequency and severity of recurrent outbreaks
• Lowers risk of viral transmission to partners when used suppressively
• Minimizes complications such as neurologic involvement in zoster
• Provides flexible dosing regimens for individualized treatment
• Well-tolerated with extensive clinical experience supporting its use

Common use

Aciclovir is indicated for the treatment of initial and recurrent episodes of herpes simplex virus infections (genital herpes, herpes labialis, herpes keratitis) and herpes zoster (shingles). It is also used for chronic suppressive therapy to prevent recurrences in immunocompetent and immunocompromised patients. Off-label uses include prophylaxis in transplant recipients and management of herpes encephalitis or eczema herpeticum under specialist supervision.

Dosage and direction

Oral tablets:

• Genital herpes (initial): 200 mg 5 times daily for 10 days
• Genital herpes (recurrent): 200 mg 5 times daily for 5 days
• Suppressive therapy: 400 mg twice daily or 200 mg 3–4 times daily
• Herpes zoster: 800 mg 5 times daily for 7–10 days

Topical cream: Apply to affected area 5 times daily at 4-hour intervals for 4 days.

Intravenous:

• Herpes simplex: 5 mg/kg every 8 hours
• Herpes zoster: 10 mg/kg every 8 hours

Dosage adjustments are required in renal impairment. Always complete the full course unless otherwise directed by a physician.

Precautions

• Maintain adequate hydration to prevent crystalluria, especially with IV administration
• Use with caution in elderly patients and those with renal impairment
• Monitor renal function during prolonged or high-dose therapy
• Topical formulation is for external use only; avoid ocular contact
• Not a cure for herpes infections; does not eliminate latent virus
• May require dosage adjustment in patients receiving nephrotoxic drugs

Contraindications

• Hypersensitivity to aciclovir, valaciclovir, or any component of the formulation
• Severe renal impairment (CrCl <10 mL/min) without appropriate dose adjustment
• History of serious neurological reactions to previous antiviral therapy

Possible side effect

Common (≥1%):

• Nausea
• Headache
• Diarrhea
• Vomiting
• Rash

Less common:

• Elevated liver enzymes
• Fatigue
• Dizziness
• Abdominal pain

Rare but serious:

• Acute renal failure
• Neurotoxicity (agitation, confusion, tremor)
• Hematologic abnormalities (thrombocytopenia, leukopenia)
• Anaphylaxis

Drug interaction

• Probenecid: Increases aciclovir plasma concentration
• Nephrotoxic drugs (e.g., aminoglycosides, cyclosporine): Increased risk of renal impairment
• Zidovudine: May cause increased drowsiness or lethargy
• Mycophenolate mofetil: Potential additive effects on immunosuppression

Missed dose

Take the missed dose as soon as remembered, unless it is almost time for the next scheduled dose. Do not double the dose to make up for a missed one. For topical formulations, resume regular application schedule.

Overdose

Symptoms may include agitation, coma, seizures, and renal impairment. Management involves supportive care and hemodialysis, which significantly enhances aciclovir clearance. Maintain adequate hydration and monitor renal function closely.

Storage

Store at room temperature (15–30°C) in original container. Protect from light and moisture. Keep out of reach of children. Do not use beyond the expiration date. Do not freeze oral suspension or intravenous solution.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Always consult a healthcare professional for diagnosis and individualized treatment recommendations. Do not initiate or discontinue therapy without professional guidance.

Reviews

“Aciclovir has been transformative in my practice for managing herpes zoster. Patients experience significant pain reduction and accelerated healing with minimal side effects.” – Dr. Elena Rostova, Infectious Disease Specialist

“As a dermatologist, I find topical aciclovir cream particularly effective for early intervention in herpes labialis. It reduces outbreak duration consistently.” – Dr. Michael Thorne, Dermatology

“Long-term suppressive therapy with aciclovir has dramatically improved quality of life for my patients with recurrent genital herpes. Well-tolerated even after years of use.” – Dr. Sarah Jenkins, OB/GYN