How to Write a Medication Order in the MAR
Complete medication orders must include: patient's full name and second identifier (e.g., medical record number, date of birth), date, diagnosis, medication's full generic name, dosage (using leading zeros for doses <1 mg, no trailing zeros), route and rate of administration, schedule/frequency, duration, and prescriber signature. 1
Essential Components of a Medication Order
Patient Identification
- Two patient identifiers required: Full name PLUS medical record number or date of birth
- Never use room number as an identifier 1
Medication Information
Write orders using this structured format:
Drug Name:
- Use full generic name only
- Include brand name ONLY when multiple formulations exist or when it helps identify a unique product
- Follow Joint Commission standards—no unapproved abbreviations 1
Dosage:
- Include the actual dose with proper decimal notation:
- Use leading zero (0.5 mg, NOT .5 mg)
- Never use trailing zeros (5 mg, NOT 5.0 mg)
- Document height, weight, and calculation variables used
- Reference the dose calculation methodology 1
Route and Rate:
- Specify exact route (PO, IV, SC, IM, PR, SL, transdermal, etc.)
- Include infusion rate for IV medications (e.g., "over 15 minutes," "continuous infusion over 24 hours") 2, 3
Frequency/Schedule:
- Use standard abbreviations: BID, TID, QID, daily, every 4 hours, PRN
- For PRN orders, specify the indication and maximum daily dose (e.g., "every 4-6 hours PRN pain, maximum 4 mg in 24 hours") 2, 4, 3
Additional Required Elements
Clinical Context:
- Diagnosis or indication for the medication
- Regimen name and cycle number (for chemotherapy)
- Protocol name/number if applicable 1
Safety Parameters:
- Allergies documented
- Criteria to treat (relevant lab values, toxicity thresholds)
- Cumulative lifetime dose if applicable (e.g., doxorubicin)
- Sequence of drug administration when relevant 1
Duration:
- Start date
- Stop date or duration of therapy
- For time-limited orders, specify the review interval 1
Practical Example Format
Using ondansetron from the guidelines 2:
Patient: John Smith, MRN: 123456
Date: [Current date]
Diagnosis: Chemotherapy-induced nausea
Allergies: Penicillin
Ondansetron 8 mg PO BID
Route: Oral
Schedule: Every 12 hours
Indication: Nausea prevention
Start: [Date]
Duration: Continue through chemotherapy cycle
Maximum: 16 mg/24 hours
Prescriber signature: _____________
Date/Time: _____________Critical Safety Considerations
Avoid These Common Errors:
- Verbal orders are prohibited except to hold or stop medication 1
- Fax and email orders are acceptable as written orders 1
- Ambiguous abbreviations cause 26-30% of medication errors 5
- Free-text orders for medications create significant error risk—always use structured formats 6
Use Standardized Forms: Preprinted or electronic order sets reduce errors by 50% and eliminate ambiguous orders from 30% to 1% 7, 8. These should list all medications in a regimen with complete dosing parameters 1.
Documentation of Refusal or Modifications: If oral medication is refused or route must be changed, document this separately with rationale and alternative plan. For PRN medications, document the assessment that prompted administration 4.
Verification Requirements: A second qualified person must independently verify the order before preparation, confirming all elements including patient identifiers, drug name, dose, volume, rate, route, and calculations 1.
The evidence strongly supports that formatted, complete orders with all required elements significantly reduce prescribing errors and improve patient safety 7, 8, 5. Missing even a single element (like dose units) compromises order safety 7.