Home Drug Guide Acyclovir Sodium

Drug Guide

Generic Name

Acyclovir Sodium

Brand Names Zovirax, Acyclovir In Sodium Chloride 0.9% Preservative Free, Acyclovir

Classification

Therapeutic: Antiviral

Pharmacological: Nucleoside analogue

FDA Approved Indications

Herpes simplex virus (HSV) infections (initial and recurrent)
Varicella (chickenpox)
Herpes zoster (shingles)

Mechanism of Action

Acyclovir is converted into acyclovir triphosphate inside infected cells, which inhibits viral DNA synthesis by incorporating into viral DNA and causing chain termination.

Dosage and Administration

Adult: Dosage varies based on infection type: for HSV, typically 200 mg orally 5 times daily for 7–10 days; for shingles, 800 mg orally 5 times daily for 7 days.

Pediatric: Dosing based on weight, generally 20-40 mg/kg/day divided into 3-5 doses, specific regimens depend on age and condition.

Geriatric: Adjustments may be necessary based on renal function; careful monitoring advised.

Renal Impairment: Reduce dose and/or extend dosing interval based on renal function (creatinine clearance).

Hepatic Impairment: No specific adjustments required.

Pharmacokinetics

Absorption: Orally, bioavailability approximately 15-30%.

Distribution: Widely distributed to body tissues and fluids, crosses blood-brain barrier.

Metabolism: Minimal hepatic metabolism; mostly excreted unchanged.

Excretion: Primarily renal excretion via glomerular filtration and tubular secretion.

Half Life: Approximately 2-3 hours in individuals with normal renal function.

Contraindications

Known hypersensitivity to acyclovir or valacyclovir.

Precautions

Use with caution in renal impairment, dehydration, or immunocompromised patients; monitor renal function during therapy.

Adverse Reactions - Common

Nausea (Common)
Headache (Common)
Malaise (Common)

Adverse Reactions - Serious

Nephrotoxicity (Rare)
Neurotoxicity (confusion, hallucinations, tremors) (Rare)
Seizures (Rare)

Drug-Drug Interactions

Probenecid (increases acyclovir levels)
Cimetidine (may reduce renal clearance)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor renal function (BUN, serum creatinine), hydration status, and CNS status especially in elderly or renal impairment.

Diagnoses:

Impaired renal function
Risk for infection

Implementation: Ensure adequate hydration during therapy; administer as prescribed, monitor for adverse effects.

Evaluation: Assess for resolution of symptoms, adverse reactions, and renal function stability.

Patient/Family Teaching

Take medication exactly as prescribed.
Stay well-hydrated during therapy.
Report any signs of adverse effects, especially confusion, decreased urination, or rash.
Maintain good hand hygiene to prevent transmission of herpes infections.

Special Considerations

Black Box Warnings:

Nephrotoxicity and neurotoxicity in high doses or with IV administration.

Genetic Factors: N/A

Lab Test Interference: None known.

Overdose Management

Signs/Symptoms: Nausea, vomiting, hallucinations, seizures, renal failure.

Treatment: Hydrate aggressively, monitor renal function, and provide supportive care; hemodialysis may be considered in severe cases.

Storage and Handling

Storage: Store at room temperature, away from moisture and heat.

Stability: Stable according to manufacturer specifications until expiry date.