Antiviral Agent: Acyclovir Powder for Injection 250 mg contains the active ingredient acyclovir, a synthetic nucleoside analog with powerful antiviral activity.
Formulation: It is supplied as a lyophilized (freeze-dried) powder that must be reconstituted with a specified diluent (e.g., Sterile Water for Injection) before intravenous (IV) administration.
Rapid Action: The injectable form is used when a rapid and high concentration of acyclovir is required in the blood, such as in severe or life-threatening infections.
Selectivity: Acyclovir is highly selective for infected cells, as it is converted to its active form only within cells infected by herpesviruses, minimizing damage to healthy host cells.
Advantages
High Systemic Concentration: Intravenous administration achieves a much higher and more reliable systemic concentration of the drug than oral forms, which is critical for treating severe infections.
Rapid Onset: Provides a rapid onset of antiviral action, which is essential for managing serious or life-threatening herpesvirus infections.
Efficacy in Severe Cases: The injectable form is the standard of care for serious herpesvirus infections, including herpes simplex encephalitis and severe neonatal herpes.
Well-Tolerated: The drug has a good safety profile, and its use in a hospital setting allows for close monitoring to manage potential side effects.
Uses
Severe Herpes Simplex Infections: The primary use is for severe mucocutaneous herpes simplex virus (HSV) infections in immunocompromised patients and for initial and recurrent genital herpes in immunocompromised patients.
Herpes Simplex Encephalitis: It is the standard treatment for herpes simplex encephalitis, a life-threatening viral infection of the brain.
Neonatal Herpes: Indicated for the treatment of neonatal herpes, which can be disseminated and life-threatening.
Varicella Zoster Virus (VZV): Used for severe infections caused by VZV, such as disseminated zoster in immunocompromised patients or chickenpox pneumonia.
Nature
Synthetic Guanosine Analog: Acyclovir is a synthetic analog of the nucleoside guanosine, one of the four building blocks of DNA.
Mechanism of Action: In infected cells, viral thymidine kinase converts acyclovir to its monophosphate form. Host enzymes further convert this to the active acyclovir triphosphate, which then competitively inhibits viral DNA polymerase, leading to the termination of the viral DNA chain.
Inhibition of Viral Replication: By terminating viral DNA synthesis, acyclovir effectively blocks the replication of the herpesvirus, but it does not completely eradicate the virus from the body.
Pharmacokinetic Profile: Following IV infusion, acyclovir is widely distributed throughout the body, including into the cerebrospinal fluid, which is essential for treating CNS infections like encephalitis.
Storage
Unreconstituted Powder: The powder for injection should be stored at controlled room temperature, typically between 20∘C to 25∘C (68∘F to 77∘F).
Protection: Keep the vial in its original packaging, protected from light and moisture.
Reconstitution & Immediate Use: The powder must be reconstituted with the specified diluent before use. The reconstituted solution must be further diluted for infusion and used within a specified time (e.g., 12 hours) to maintain its stability.
Avoid Freezing: The reconstituted solution should not be frozen or refrigerated as precipitation may occur. Any unused portion must be discarded safely.
