62 yo female, hx type 2 dm, Htn, thyroid cancer, with current symptoms of pain, burning, tingling and itching left posterior neck & head (scalp), no lesions, sore muscle/tendon of left posterior neck. Dx from a clinic was shingles. NP in clinic was newly graduated and prescribed 500mg Valtrex bid opposed to Valtrex 1 gm tid. Pharmacist at A Walmart said the dosage for shingles would be Valtrex 500mg once daily???? What should be the dosage and could this be something other than shingles. I am also very tired.