Acyclovir Injection IV 500mg

About Acyclovir Injection IV 500mg

Uses

• Treats severe herpes simplex virus (HSV) infections in hospitalized patients
• Manages disseminated or severe varicella-zoster (chickenpox and shingles) infections
• Treats herpes simplex encephalitis, a serious brain infection
• Prevents herpes virus reactivation in immunocompromised patients undergoing chemotherapy or transplant
• Manages severe genital herpes outbreaks that do not respond to oral treatment

Benefits

• Delivers full antiviral dosing directly into the bloodstream for faster action in severe illness
• Reduces the risk of life-threatening complications from herpes encephalitis
• Shortens hospital recovery time when started early in severe infections
• Useful for patients who cannot swallow or absorb oral antiviral tablets

What Experts Say

Physicians reserve intravenous acyclovir for patients who cannot tolerate oral antivirals or who have infections severe enough to threaten organs, such as herpes encephalitis or disseminated herpes zoster. Dosing is calculated by body weight and kidney function, since the drug is cleared almost entirely through the kidneys.

Doctors infuse each dose slowly over at least one hour and ensure the patient is well hydrated before and during treatment. This step lowers the risk of acyclovir crystals forming in the kidney tubules, a known cause of acute kidney injury with fast or concentrated infusions.

Hospitals in Pakistan commonly monitor renal function and urine output throughout the course, adjusting the dose if creatinine rises. Physicians treat herpes encephalitis and severe zoster as medical emergencies, since untreated cases carry a high risk of lasting neurological damage or complications.

Drug Class

• Antiviral (Synthetic Purine Nucleoside Analogue)

Acyclovir Injection IV 500mg formula

• Acyclovir 500mg (Sodium salt, IV)

Available forms

• 500mg IV Injection Vial (10ml, powder for reconstitution)

How to use Acyclovir Injection IV 500mg?

• Give only as a slow intravenous infusion over at least one hour, never as a rapid injection
• Dose is calculated according to the patient's body weight and kidney function
• Ensure the patient is adequately hydrated before and during each infusion
• Reconstitute and dilute strictly according to hospital pharmacy protocol before use
• Administer only under direct medical supervision in a hospital setting
• Complete the full course as prescribed by the treating physician

Drug Interactions

• Increases kidney injury risk when combined with other nephrotoxic drugs such as aminoglycosides, cyclosporine, or tacrolimus
• Probenecid reduces renal clearance of acyclovir and raises its blood levels
• Combining with other antiviral drugs may increase the risk of toxicity without added benefit
• Use with NSAIDs may further raise the risk of kidney impairment
• Mycophenolate mofetil can increase blood levels of both drugs when combined

Risks and warnings

• Carries a real risk of nephrotoxicity, especially with rapid infusion or dehydration
• Requires adequate hydration before and throughout treatment to protect the kidneys
• Reserved for hospital administration under close medical and renal monitoring
• Dose adjustment is required in patients with pre-existing kidney impairment
• May cause confusion, tremors, or agitation, particularly in elderly or renally impaired patients
• Use with caution in pregnancy and breastfeeding, only when clearly indicated by a doctor
• Extravasation during infusion can cause local tissue irritation and inflammation

Acyclovir Injection Side Effects

• Pain, redness, or swelling at the injection site
• Nausea and vomiting
• Elevated kidney function markers (creatinine, urea)
• Headache and dizziness
• Confusion, tremors, or agitation in some patients
• Skin rash
• Low blood pressure during infusion
• Liver enzyme elevation

Storage Conditions

• Store unopened vials at room temperature, between 15°C and 25°C
• Protect vials from light and keep away from direct heat
• Use the reconstituted solution within the time specified by hospital pharmacy protocol
• Discard any diluted solution that shows crystallization or particles
• Keep out of reach of children
• Dispose of used vials and needles according to hospital sharps disposal procedure