Home Drug Guide Vidarabine

Drug Guide

Generic Name

Vidarabine

Brand Names Vira-A

Classification

Therapeutic: Antiviral

Pharmacological: Nucleoside analog

FDA Approved Indications

  • Herpes simplex virus (HSV) infections of the eye

Mechanism of Action

Vidarabine is a nucleoside analog that inhibits viral DNA synthesis by competing with natural nucleotides, leading to chain termination during viral DNA replication.

Dosage and Administration

Adult: Apply 1% ophthalmic ointment to the affected eye every 3 hours during the day and every 4 hours during the night, for 7-14 days.

Pediatric: Same as adult dosing; dosages are based on the severity of the infection and patient response.

Geriatric: No specific adjustments; follow standard dosing unless renal or hepatic impairment present.

Renal Impairment: Use with caution; no specific dose adjustment provided, but monitor renal function.

Hepatic Impairment: Use with caution; no specific dose adjustment provided.

Pharmacokinetics

Absorption: Poor oral absorption; topical administration for ocular use.

Distribution: Limited systemic absorption; mostly localized effect.

Metabolism: Metabolized by deamination.

Excretion: Primarily renally excreted.

Half Life: Approximately 20-25 minutes systemically; topical ocular half-life varies.

Contraindications

  • Hypersensitivity to vidarabine or any component

Precautions

  • Use with caution in immunocompromised patients.
  • Potential for neurotoxicity if used systemically.

Adverse Reactions - Common

  • Local irritation, burning, or stinging of the eye (Frequent)
  • Conjunctivitis or eyelid inflammation (Occasional)

Adverse Reactions - Serious

  • Neurotoxicity (e.g., seizures, altered consciousness) if systemically absorbed (Rare)

Drug-Drug Interactions

  • None well-documented; check for other ocular medications.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor for signs of ocular irritation or allergic reactions.

Diagnoses:

  • Risk for infection related to impaired ocular integrity.

Implementation: Apply ointment as prescribed; ensure proper eye hygiene.

Evaluation: Assess resolution of infection and monitor for adverse effects.

Patient/Family Teaching

  • Use medication exactly as prescribed.
  • Avoid touching the tip of the tube to any surface.
  • Report any eye pain, vision changes, or Allergic reactions.

Special Considerations

Black Box Warnings: N/A

Genetic Factors: None specified.

Lab Test Interference: None known.

Overdose Management

Signs/Symptoms: Local ocular irritation or systemic neurotoxicity in case of significant systemic absorption.

Treatment: Discontinue drug; provide symptomatic and supportive care.

Storage and Handling

Storage: Store at room temperature, protected from light.

Stability: Stable as per manufacturer; discard after expiration.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.