Acyclovir

C. diff Risk

None

Oral Bioavailability

Moderate

Spectrum Of Activity

Dosing

Meningitis20 mg/kg/dose IV every 8 hours x 21 days

Meningitis20 mg/kg/dose IV every 8 hours x 21 days

Meningitis1 to <3 months
20 mg/kg/dose IV every 8 hours x 21 days

3 months-11 yrs
15 mg/kg/dose IV every 8 hours x 21 days

>12 years
10 mg/kg/dose IV every 8 hours x 21 days

  • Use ideal body weight for dosing obese patients (BMI ≥30 kg/m2)

5-10 mg/kg IV every 8 hr

Consider higher dosing for serious infections such as CNS and disseminated zoster
10mg/kg IV every 8 hr

Shingles
800 mg PO 5 times per day

Prophylaxis dosing varies by indication

CrCl < 10 ml/min CrCl 10 - 25 ml/minCrCl 26 - 50CrCl > 505 mg/kg IV every 24 hr, or half of regular dose every 4 hr10mg/kg IV every 24 hr10mg/kg IV every 12 hr10mg/kg IV every 8 hr (Regular dosing)

2.5-5mg/kg IV every 24 hr

Consider 2.5 mg/kg x1 a loading dose for serious infections

5-10 mg/kg IV every 24 hr

Use upper end for CNS infections

General Information

For oral indications, valacyclovir is the pro-drug, which is more bioavailable with more convenient dosing.

  •  GI upset

  •  Phlebitis/Extravasation

  •  Increased SCr

  •  AKI from crystal nephropathy

  •  CNS Effects (confusion, tremor, lethargy, hallucination)

Therapy for herpesviral infections (HSV and VZV) including encephalitis.

Prophylaxis of herpesviral infections if recurrent disease or immunocompromised.

Lab

  • Follow SCr as appropriate

  • Check urine for crystals if AKI suspected

  • Ensure adequate hydration for the patient

  • Phlebitis (with IV formulation)

Clinical

  • CNS effects

  • Ensure adequate hydration for the patient

  • Phlebitis (with IV formulation)

Mycophenolate can increase the acyclovir concentration

May diminish efficacy of zoster or varicella vaccine

Antimicrobial class: Antiviral. Nucleoside analogue.

Pregnancy category: B

Average serum half life: 3 hours

CSF penetration: Therapeutic

Urine penetration: Therapeutic