👤 By the CinnaRN Clinical Content Team🕐 Updated 2026-08-23🏷️ Pharmacological Therapies🔖 Free to read, print, and share
Also known as: Zovirax · acyclovir · valacyclovir · Valtrex · herpes medication · shingles drug
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Use this quick-reference guide to spot, treat, and prevent Acyclovir on the NCLEX. Keep it handy during review and on exam day!
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📒 The 1-minute cheat sheet
📌 Use
Herpes, shingles, varicella
Suppresses, NOT a cure
📌 Toxic
Nephrotoxic (IV) → crystalluria
Monitor BUN/creatinine
✅ Do
Push fluids → prevent crystals
IV slow over 1 hr
Start early at first symptom
🎓 Teach
Still contagious → no contact lesions
Report ↓urine output
📚 Acyclovir — full study notes
The cheat sheet above is your quick recall card. These notes go deeper — what it is, what to do first, what must be reported, and what to teach.
Acyclovir is an antiviral used to treat herpes simplex, varicella (chickenpox), and herpes zoster (shingles). It does not cure these viruses but shortens outbreaks and reduces severity, working best when started early. The key safety concern is nephrotoxicity from crystal formation, prevented by adequate hydration, especially with IV use.
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Key points
Understand these first
Acyclovir is an antiviral that inhibits viral DNA replication but does not eradicate the latent virus.
It is most effective when started at the earliest sign of an outbreak.
IV acyclovir can crystallize in the kidneys and cause nephrotoxicity if the patient is dehydrated.
It is infused slowly over at least 1 hour to reduce kidney injury risk.
Doses are reduced in patients with renal impairment.
It reduces transmission and outbreak frequency but does not prevent spread entirely.
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Nursing priorities
What to do, in order
Maintain adequate hydration before and during IV therapy to prevent crystalluria.
Infuse IV acyclovir slowly over at least 1 hour and never as a rapid bolus.
Monitor renal function and urine output during treatment.
Teach the patient to start oral therapy at the first sign of an outbreak.
Use standard and contact precautions and good hand hygiene when handling lesions.
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Red flags — report now
Escalate immediately
Decreased urine output, flank pain, or rising creatinine may signal nephrotoxicity and must be reported.
Confusion, tremors, or hallucinations may indicate CNS toxicity, more common in renal impairment.
Never give rapid IV bolus acyclovir because it increases kidney injury risk.
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Labs & values
Numbers to know
BUN 7-20 mg/dL (monitor renal function)
Serum creatinine 0.6-1.2 mg/dL (dose reduced if elevated)
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Patient teaching
What patients must know
Start the medication at the first sign of tingling, itching, or blistering.
Drink plenty of fluids while taking this medication.
This drug controls outbreaks but does not cure the infection, and you can still transmit it.
Use barrier protection and avoid contact with lesions to prevent spreading the virus.
❓ Acyclovir: NCLEX FAQs
What are the priority nursing interventions for Acyclovir?
Maintain adequate hydration before and during IV therapy to prevent crystalluria. Infuse IV acyclovir slowly over at least 1 hour and never as a rapid bolus. Monitor renal function and urine output during treatment. Teach the patient to start oral therapy at the first sign of an outbreak.
What are the warning signs of Acyclovir a nurse must report?
Decreased urine output, flank pain, or rising creatinine may signal nephrotoxicity and must be reported. Confusion, tremors, or hallucinations may indicate CNS toxicity, more common in renal impairment. Never give rapid IV bolus acyclovir because it increases kidney injury risk.
What do I need to know about Acyclovir for the NCLEX?
Acyclovir is an antiviral that inhibits viral DNA replication but does not eradicate the latent virus. It is most effective when started at the earliest sign of an outbreak. IV acyclovir can crystallize in the kidneys and cause nephrotoxicity if the patient is dehydrated. It is infused slowly over at least 1 hour to reduce kidney injury risk.
What patient teaching is important for Acyclovir?
Start the medication at the first sign of tingling, itching, or blistering. Drink plenty of fluids while taking this medication. This drug controls outbreaks but does not cure the infection, and you can still transmit it. Use barrier protection and avoid contact with lesions to prevent spreading the virus.
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Quick Tip
Acyclovir is an antiviral that inhibits viral DNA replication but does not eradicate the latent virus.