In another site, it mentions that with Treatment of Shingles that your doctor could only really prescribe something in the first 72 hours, but read on, there are smaller, less effective treatments:

Mild attacks of shingles require symptomatic treatment only. There is no benefit with anti-viral drugs.

In moderate-severe attacks - add oral aciclovir - 800mg five times per day for 7 days - reduces the duration of rash and severity of pain. Patients with the worst pain benefit the most. Acyclovir must be given within 72 hours of the onset of the rash.

Immunocompetent patients with severe disease, immunocompromised patients, ophthalmic shingles, and motor shingles are the cases that benefit the most from acyclovir, and may require it intravenously - 10mg/kg or 500mg/m2 tds.

Famciclovir and valaciclovir are newer agents, and are as effective as aciclovir in the treatment of immunocompetent patients.

Wet dressings with tap water or 5% aluminum acetate applied to affected skin for 30-60 minutes 4-6 times per day can bring symptomatic relief

Calamine lotion can be used to relieve pruritis.