Valtrex dosage guide: how much to take and when
Choosing the right dose of Valtrex (Valacyclovir) is the most important practical decision after starting therapy. Valtrex is supplied as tablet in 500mg, 1000mg, and the right dose for a given person depends on the indication, age, comorbidities and tolerance to the active ingredient Valacyclovir.
Starting dose and titration
According to the prescribing information, most adults begin Valtrex at the lowest available strength of 500mg, 1000mg and titrate up only if symptom control is insufficient and tolerability is good. Higher doses are reserved for selected cases. Older adults, people with renal or hepatic impairment, and those taking interacting medications should usually start at the lowest dose.
When to adjust
Dose adjustment is guided by symptom response and side effect burden, not by arbitrary schedules. Valacyclovir is rapidly and almost completely converted to acyclovir during first-pass intestinal and hepatic metabolism by valacyclovir hydrolase. If side effects are limiting at a given dose, going down a step is usually preferred over stopping abruptly. If the response is incomplete after several weeks, a higher dose can be tried under medical supervision.
Frequently asked questions
What is the standard starting dose of Valtrex? ▾
Most adults start Valtrex at the lowest strength of 500mg, 1000mg, with adjustment based on symptom response and tolerance. Older adults and those with reduced kidney or liver function generally start lower. The prescriber decides the exact starting dose for each person.
Can I take a higher dose of Valtrex if it isn't working? ▾
Higher doses of Valtrex should only be used after consulting the prescriber. Doubling on your own is unsafe, especially with active ingredients in the Antiviral Medications class. The prescriber can confirm whether titration is appropriate or whether the medication needs to be changed.
More on Valtrex
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