Acyclovir

Generic Name: acyclovir

Herpes Simplex Virus Nucleoside Analog DNA Polymerase Inhibitor [EPC]Over-the-Counter (OTC)

Brand Names:

Acyclovir

Acyclovir is a synthetic nucleoside analogue active against herpesviruses. Available as 400 mg or 800 mg tablets for oral administration.

Overview

Acyclovir is a synthetic nucleoside analogue active against herpesviruses. Available as 400 mg or 800 mg tablets for oral administration.

Uses

Indicated for acute treatment of herpes zoster (shingles), treatment of initial and recurrent episodes of genital herpes, and treatment of chickenpox (varicella).

Dosage

Herpes Zoster: 800 mg orally every 4 hours, 5 times daily for 7-10 days. Genital Herpes initial: 200 mg every 4 hours, 5 times daily for 10 days. Chronic suppressive therapy: 400 mg twice daily for up to 12 months. Chickenpox: Children 2+ years: 20 mg/kg per dose 4 times daily for 5 days. Adults/children >40 kg: 800 mg 4 times daily for 5 days.

Side Effects

Common adverse events include nausea (2.7-4.8%), diarrhea (2.2-3.2%), headache, and malaise. Post-approval reports include renal failure, CNS symptoms (confusion, hallucinations, seizures), severe cutaneous reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis), hepatitis, and thrombocytopenia.

Interactions

Coadministration of probenecid with acyclovir increases mean half-life and area under concentration-time curve while reducing urinary excretion and renal clearance. Use caution when administering with potentially nephrotoxic agents.

Warnings

Renal failure, sometimes fatal, has occurred with acyclovir therapy. Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome has resulted in death in immunocompromised patients. Severe cutaneous adverse reactions including Stevens-Johnson syndrome have been reported. Monitor renal function and maintain adequate hydration.

Pregnancy

Pregnancy Category B. Acyclovir was not teratogenic in animal studies at exposures 9-106 times human levels. A prospective registry of 749 first-trimester pregnancies showed birth defect rates approximating the general population. Use during pregnancy only if potential benefit justifies potential risk.

Storage

Store at 20-25°C (68-77°F). Protect from light and moisture.

Frequently Asked Questions

What is Acyclovir used for?

Indicated for acute treatment of herpes zoster (shingles), treatment of initial and recurrent episodes of genital herpes, and treatment of chickenpox (varicella).

What are the side effects of Acyclovir?

Common adverse events include nausea (2.7-4.8%), diarrhea (2.2-3.2%), headache, and malaise. Post-approval reports include renal failure, CNS symptoms (confusion, hallucinations, seizures), severe cutaneous reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis), hepatitis, and thrombocytopenia.

Can I take Acyclovir during pregnancy?

Pregnancy Category B. Acyclovir was not teratogenic in animal studies at exposures 9-106 times human levels. A prospective registry of 749 first-trimester pregnancies showed birth defect rates approximating the general population. Use during pregnancy only if potential benefit justifies potential risk.

What are the important warnings for Acyclovir?

Renal failure, sometimes fatal, has occurred with acyclovir therapy. Thrombotic thrombocytopenic purpura/hemolytic uremic syndrome has resulted in death in immunocompromised patients. Severe cutaneous adverse reactions including Stevens-Johnson syndrome have been reported. Monitor renal function and maintain adequate hydration.

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Medical Disclaimer

This drug information is for educational purposes only and should not replace professional medical advice. Drug information is sourced from the FDA National Drug Code Directory and Structured Product Labeling. Always consult with a healthcare provider before starting, stopping, or changing any medication.