PHARMACOKINETICS
Absorption: after oral administration, valacyclovir hydrochloride is rapidly absorbed from the gastrointestinal (GI) tract and converted to acyclovir and L-valine.
Distribution: The binding of valacyclovir to human plasma proteins ranged from 13.5% to 17.9%.
Bioavailability: 54.5% ± 9.1%
Metabolism: It is metabolized by liver; valacyclovir is rapidly and nearly completely converted to acyclovir and L-valine via first pass effect.
Half life: 2.5 to 3.3 hours

PHARMACODYNAMIC
After oral administration Valacyclovir metabolizes to acyclovir and valin. Acyclovir is converted to Acyclovir triphosphate which inhibits Viral DNA polymerase and then incorporates into, terminates growth and finally inactivates the virus

Shingles (Herpes zoster): The recommended dose is 1 g PO q8hr for 7 days.
Chicken pox (Varicella zoster): the recommended dose is 1g po q8hr for 7 days.
Genital herpes(Herpes simplex virus): The recommended dose is 1 g PO q12hr for 10 days
Cold sores (Herpes labialis): The recommended dose is 2 g PO q12hr for 1 day.

Headache
Elevated aspartate transaminase (AST)
Nausea
Elevated alanine transaminase (ALT)
Abdominal pain
Menstrual cramping/pain
Depression
Joint pain
Vomiting
Dizziness
Skin rash
Runny or stuffy nose
Low platelet count (thrombocytopenia)
Low white blood cell count (leukopenia, neutropenia)
Tired feeling
Stomach pain
Sore throat

It should not be given in patients with suspected Hydration status
Patients with renal impairment and in elderly patients
Hepatic impairment
Liver transplantation