The phrase "once on alternate days" in a medicine prescription means that you should take the medication every other day, rather than every day. It is a dosing instruction that indicates you should take the prescribed medicine on a specific schedule where there is a 24-hour interval between each dose.
For example, if you were prescribed a medication "once on alternate days" and you start taking it on a Monday, you would take the medication on Monday and then skip Tuesday. You would take it again on Wednesday and then skip Thursday, and so on, continuing this pattern throughout the treatment course.
This dosing regimen is typically used for certain medications where daily dosing is not necessary or might be too frequent. It allows the medication to stay active in your system for an extended period, providing the desired therapeutic effect while reducing the overall frequency of administration.
As with any prescription, it's essential to follow the dosing instructions provided by your healthcare professional accurately. If you have any doubts or concerns about how to take your medication, always consult your doctor or pharmacist for clarification.