Varicella (chicken pox) / herpes zoster

Please refer to the infection control manual

If <48 hours after the onset of a rash:

Aciclovir oral 800mg five times daily

or

Aciclovir IV^* 10mg/kg 8 hourly

or

Valaciclovir oral 1g 8 hourly

For both agents adjust dose in renal impairment - see BNF for details.

Total course duration: 7 days.

^*Aciclovir IV:

• Consider IV administration if severely immunocompromised or there is reduced enteral absorption
• Adjust dose if CrCl <50ml/minute. For further details see BNF or Summary of Product Characteristics. Use the CrCl calculator in the GGC Medicines App or on the StaffNet Hub Clinical Info page (NHSGGC network access required), or use the equation here.
• To avoid excessive dosage in obese patients (i.e. when BMI>30kg/m²), calculate the dose on the basis of adjusted body weight (AdjBW) for the patient's height.

AdjBW = ideal body weight + 0.4 x (actual body weight - ideal body weight)

• Please see table 1 here for further guidance on ideal body weight.