q1d

Medical abbreviation · Prescription

q1d stands for Once daily, a prescription abbreviation.

Rare variant for a single daily dose that ISMP lists as error-prone because "q1d" can be misread as "qid" (four times daily), the same hazard that led to QD being banned.

Example: The fax said "digoxin 0.125 mg q1d", so the pharmacist called to confirm it was once daily.

Usage notes

ISMP's recommended alternative is simply "daily". The case illustrates a general rule in medication safety: substituting a different abbreviation for a banned one (q1d, qday, o.d.) rarely solves the problem, whereas plain words do.

Related abbreviations

More prescription abbreviations

• OD – Omni die (once daily)
• OJ – Orange juice
• PC – Post cibum (after meals)
• PRN – Pro re nata (as needed)
• q.s. – Quantum sufficit (a sufficient quantity)
• q12h – Every 12 hours
• q24h – Every 24 hours
• q2h – Every 2 hours
• q2wk – Every 2 weeks
• q3h – Every 3 hours
• q4-6h – Every 4 to 6 hours
• q4h – Every 4 hours

See all 77 prescription abbreviations →

Edited by the AbbreviationList.com team. Spotted an error or a missing meaning? Contact us.

This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.