Table 1. Antiviral Drugs Used For VZV Infection.

Medication	Dosage (Adult)	Dosage (Pediatric)	Duration^#	Most common adverse effects	Average wholesale price
Oral formulations:
Acyclovir	800 mg 5x daily	20 mg/kg 4x per day, maximum 3200 mg per day	Varicella: 5 days Zoster: 7-10 days	Malaise, headache, nausea, vomiting	200 mg cap; $0.15 per cap
Valacyclovir	1 gm 3x daily	Not established	Zoster: 7 days	Headache, nausea, abdominal pain	500 mg tab; $5.93 per tab
Famciclovir	500 mg 3x daily^@	Not established	Zoster: 7 days	Headache, nausea, fatigue, diarrhea	500 mg tab $10.81 per tab
Brivudine	125 mg 1x daily^ψ	5 mg/kg/d in 3 divided doses every 8h^ψ	Zoster: 5-7 days	Gastrointestinal discomfort, nausea, vomiting, headache	Not available in U.S.
Intravenous formulations:
Acyclovir	10 mg/kg every 8 h	10 mg/kg every 8 h or 500 mg/m² every 8 h *	7-10 days	Phlebitis, renal dysfunction (acute renal failure possible)	$9.60 per 500 mg vial
Foscarnet^§	180 mg/kg per day in 2-3 divided doses	Not established	7-14 days	Fever, headache, renal dysfunction, electrolyte abnormalities, nausea, vomiting diarrhea, anemia, granulocytopenia	24 mg/ml; $70.08 per 250 ml
Cidofovir^¶	5 mg/kg every week x 2 doses, then 5 mg/kg every 2 weeks; Probenecid must be given with each dose of cidofovir.	Not established	Not established	Renal dysfunction (can be severe), fever, nausea, vomiting, anemia, neutropenia, uveitis, iritis, ocular hypotony, rash, alopecia, Falconi syndrome	75 mg/ml; $888.00 per 5 ml

^#Durations listed represent general guideline only. Exact duration of antiviral therapy depends on the immune status and clinical response of the patient. Longer duration are required for immunocompromised patients and/or for treatment of severe infections, such as disseminated infection, encephalitis, or severe pneumonitis.

^@Famciclovir dose is 250 mg 3x daily in Europe.

^ψBrivudine has also been used at 125 mg 4x daily for adults and 15mg/kg/d for children.

* Some experts has recommended 20 mg/kg every 8 h for herpes zoster in immunocompromised pediatric patients <12 years old (4) and for VZV encephalitis in children.

^§Foscarnet is not licensed for treatment of varicella or zoster, but can be used for treating VZV strains that are resistant to acyclovir or other nucleoside analogues. Dosage listed was established for treatment of CMV retinitis in HIV-infected patients.

^¶Cidofovir is not licensed for treatment of varicella or zoster, but can be considered for treating VZV strains that are resistant to both acyclovir and foscarnet. Dosage listed was established for CMV retinitis in HIV-infected patients.

Table 2. Adjunctive Therapy for Post-Herpetic Neuralgia. [Adapted from Dworkin et al. (58)]

Medication	Beginning dosage	Titration	Maximum dosage	Most common adverse effects
Analgesics:
Oxycodone	2.5-5 mg every 4 h as needed	Increase dose by 50-100% daily, every 2 days as tolerated	Usual effective dose 10-30 mg every 4 h; consider pain specialist evaluation if dosages >120 mg per day	Nausea, vomiting, constipation, somnolence, dizziness
Tramadol	25-50 mg 2x daily	Increase by 50-100 mg per day in divided doses every 2 days as tolerated	100 mg 4x daily	Nausea, vomiting, constipation, somnolence, dizziness, seizures, postural hypotension
Tricyclic antidepressants:
Nortriptyline	25 mg at bedtime	Increase by 25 mg per day every 2-3 days as tolerated	Usual effective dose 75 mg at bedtime or 75 mg 2x daily; maximum 150 mg per day	Sedation, dry mouth, blurred vision, weight gain, urinary retention
Anti-epileptics:
Gabapentin	300 mg at bedtime	Increase to 300 mg 2x daily on day 2 and 300 mg 3x daily on day 3, then increase by 100-300 mg 3x daily every 2-3 days as tolerated	Usual effective dose 600-1200 mg 3x daily, but no additional benefit has been shown for dose >1800 mg per day	Somnolence, dizziness, peripheral edema, ataxia
Pregabalin	75 mg 2x daily or 50 mg 3x daily	Can titrate to 300 mg per day within 1 week as tolerated; for patients without sufficient pain relief at 300 mg per day, can further titrate to 600 mg per day after 2-4 weeks as tolerated	600 mg per day in 2-3 divided doses	Somnolence, dizziness, peripheral edema, ataxia, headache, weight gain
Steroids:
Prednisone	60 mg daily for 7 days	Decrease dose by half every 7 days to 15 mg per day; then discontinue after 7 days at 15 mg daily	60 mg daily	Gastrointestinal distress, nausea, changes in mood, edema