What does Q4-6H mean on a prescription?
Q4-6H means every 4 to 6 hours.
What it stands for
Q4-6H comes from the Latin quaque, meaning every. It tells you the interval between doses, as a range rather than a fixed time.
How it looks on a real label
| Sig code | Label directions |
|---|---|
1-2 tabs po q4-6h prn pain | Take 1 to 2 tablets by mouth every 4 to 6 hours as needed for pain |
1 tab po q6h prn fever | Take 1 tablet by mouth every 6 hours as needed for fever |
2 caps po q8h | Take 2 capsules by mouth every 8 hours |
The Q is from the Latin quaque, meaning every, and the number is the hours between doses. Q6H is every 6 hours, Q8H every 8, and so on.
A range like 4 to 6 rather than a fixed interval usually appears on a PRN medication. It sets a floor, not a schedule: wait at least 4 hours, and do not go longer than 6 if the symptom is still there.
The floor is the part that matters for safety. Taking a Q4-6H medication every 2 hours is how an accidental overdose happens with something as ordinary as acetaminophen, which is why the label carries the interval as well as a daily maximum.
Related codes
| Code | Meaning |
|---|---|
PRN | as needed |
Q8H | every 8 hours |
PO TID | by mouth three times daily |
STAT | immediately |
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This page is educational and is not medical advice. Always follow the directions on your own prescription and ask your pharmacist if anything is unclear.