For this indication, competent medicine agencies globally authorize below treatments:
Oral
30 - 120 mg
From 7.5 To 30 mg 4 time(s) per day every day
Doses of 30 to 120mg are given at intervals throughout the day when maximum strength is needed (for example, on rising and before mealtimes). The usual duration of action of a dose is 3 to 4 hours in the daytime but a longer effect (6 hours) is often obtained with a dose taken on retiring for bed.
The total daily dose is usually in the range of 5–20 tablets but doses higher than these may be needed by some patients.