Acyclovir or Aciclovir is a guanosine analogue antiviral drug, marketed under trade names such as Zovirax, Cyclovir, Herpex, Acivir, Acivirax, and Zovir. Acyclovir is one of the most commonly used antiviral drugs and is primarily used for the treatment of herpes simplex virus infections, as well as in the treatment of varicella zoster (chickenpox) and herpes zoster (shingles).
Acyclovir is a synthetic purine nucleoside analogue with in vitro and in vivo inhibitory activity against herpes simplex virus types 1 (HSV-1), 2 (HSV-2), and varicella-zoster virus (VZV). When Acyclovir is administered orally, peak plasma concentration occurs after 1â€“2 hours. Aciclovir has a high distribution rate and only 30% is protein-bound in plasma. The elimination half-life of aciclovir is approximately 3 hours. It is renally excreted.
Acyclovir is available as Generic Zovirax Tablets which is packaged in tablets of 200 mg, 400 mg and 800 mg. Each 200 mg, 400 mg and 800 mg tablet of Generic Zovirax contains 200 mg, 400 mg and 800 mg of acyclovir respectively.
Aciclovir (Generic Zovirax) is indicated for the treatment of HSV and VZV infections, including:
Common adverse drug reactions (occurring in 1% of patients or more) associated with systemic acyclovir therapy include nausea, vomiting, diarrhea and/or headache. In high doses, hallucinations have been reported. Infrequent adverse effects (0.1-1% of patients) include: agitation, vertigo, confusion, dizziness, oedema, arthralgia, sore throat, constipation, abdominal pain, hair loss, rash and/or weakness. Rare adverse effects (<0.1% of patients) include: coma, seizures, neutropenia, leukopenia, crystalluria, anorexia, fatigue, hepatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis and/or anaphylaxis.
Renal impairment has been reported when acyclovir is given in large, fast doses intravenously, due to the crystallisation of acyclovir in the kidneys.
Given below is the recommended dosage for adults for the treatment of various indications:
Acute Treatment of Herpes Zoster: 800 mg every 4 hours orally, 5 times daily for 7 to 10 days.
Genital Herpes: Treatment of Initial Genital Herpes: 200 mg every 4 hours, 5 times daily for 10 days.
Chronic Suppressive Therapy for Recurrent Disease: 400 mg 2 times daily for up to 12 months
Generic Zovirax is contraindicated in patients who develop hypersensitivity to acyclovir or valacyclovir.
Additional Info: Prescribing Information
Considerable portions of the text here is from http://en.wikipedia.org/wiki/Aciclovir and is reproduced here under the Creative Commons Attribution-ShareAlike License