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Acyclovir
SIMPLE EXPLANATION
What is it and what does it do?
Acyclovir is an antiviral medication that inhibits viral DNA replication, typically used for various herpes viruses.
DETAILED EXPLANATION
Action: virus-specific thymidine kinase convert acyclovir to acyclovir monophosphate, which is
then converted to acyclovir triphosphate by other cellular enzymes.
Availability: prescription only.
Class (Chemical): purine nucleoside analog.
Class (Functional): antiviral.
Contraindications: hypersensitivity to acyclovir, valacyclovir, or milk protein.
Dose: Herpes Simplex: Adult PO: 400mg 3x/day for 5 days OR 200mg 5x/day for 5 days
Over 12 IV: 5mg/kg over 1hr q8hrs for 7 days
3mos to 12yrs IV: 10mg/kg q8hrs for 7 days
Neonate IV: 10mg/kg q8hrs for 10 days
Herpes Simplex Encephalitis: Adult IV: 10mg/kg over 1hr q8hrs for 10 days
3mos to 12yrs IV: 10-15mg/kg q8hrs for 4-21 days
Birth to 3mos IV: 20mg/kg q8hrs for 21 days
Premature to Neonate IV: 10mg/kg q12hrs for 14-21
days
Herpes Labialis, Recurrent: Over 12yrs TOP: apply 5x/day for 4 days
begin as soon as symptoms appear
Herpes Zoster: Adult PO: 800mg q4hrs for 7-10 days
Adult IV: 10mg/kg q8hrs for 7 days
Varicella: Over 2yrs PO: 10mg/kg (max 800mg) 4x/day for 5 days
Genital Herpes, Initial: Adult PO: 400MG 3x/day OR 200mg 5x/day for 7-10 days
Adult TOP: apply for 5 days
Adult IV: 5mg/kg q8hrs OR 750mg/m2/day divided q8hrs for 7-
10 days
Genital Herpes, Episodic: Adult PO: 400mg 3x/day OR 800mg 2x/day for 5 days
OR 800mg 3x/day for 2 days
Initiate within 1 day of lesion onset
Genital Herpes, Suppression: Adult PO: 400mg 2x/day OR 200mg 3-5x/day for up to
12 months
Interactions: zidovudine will increase CNS side effects; increase levels of probenecid and put patient at risk for toxicity; aminoglycosides will increase risk of nephrotoxicity;
increase the concentrations of entecavir, pemetrexed, tenofovir, and theophylline;
decrease action of hydantoins, valproic acid.
Labs: elevated ALT/AST; increased BUN and creatinine; decrease in WBCs.
Notes: does not cure infections, just controls symptoms.
Off-Label Use: Bell’s palsy when used in conjunction with prednisolone; prevention of
cytomegalovirus, Epstein-Barr virus, esophagitis, hairy leukoplakia, herpes
labialis, herpes simplex, herpes simplex ocular, keratoconjunctivitis, pharyngitis,
pneumonitis, postherpetic neuralgia, proctitis, stomatitis, tracheobronchitis,
varicella.
Precautions: breastfeeding; dehydration; electrolyte imbalance; hypersensitivity to famciclovir,
ganciclovir, or penciclovir; obesity; pregnancy; renal, hepatic, or neurologic disease.
Report to Provider: difficulty breathing; lower back pain.
Routes: BUC; IV; PO; TOP.
Side Effects: confusion; hallucinations; tremors; lethargy; seizures; dizziness; headache;
encephalopathic changes; gingival hyperplasia; nausea; vomiting; diarrhea;
abdominal pain; colitis; changes in menses; hematuria; acute renal failure;
hemolytic uremic syndrome; thrombotic thrombocytopenia purpura; leukopenia (in
immunocompromised patients); urticaria; rash; pruritis; pain or phlebitis at IV site;
alopecia; unusual sweating; Stevens-Johnson syndrome; joint pain; angioedema;
anaphylaxis.
Uses: herpes simplex virus (mucocutaneous); herpes genitalis (HSV-1, HSV-2); varicella; herpes
zoster; herpes simplex encephalitis.
Reference: Mosby's Nursing Drug Reference