Fast Fact and Concept #18: Oral Opioid Dosing Intervals

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Title: Fast Fact and Concept #18: Oral Opioid Dosing Intervals

Author(s): Weissman, D.

This Fact Fact reviews prescribing recommendations for oral short-acting opioids and opioid-non opioid combination products. It can be used as the starting point for discussion on ward rounds or for a pain teaching conference.

Educational Objective(s):
Learn the appropriate dosing intervals for short-acting oral opioids.
A new patient was referred to see me about cancer pain management. She was taking an oxycodone/acetaminophen combination product for breakthrough pain. I asked her how long it provided pain relief; she said, "only about 3 hours". I asked how often she takes it, she said, "every 6 hours, that's what it says on the bottle".

The most commonly prescribed oral opioids include the short-acting products, administered as either single agents (oral morphine, hydromorphone, oxycodone and codeine) or as combination products containing acetaminophen or aspirin (e.g. Percocet, Roxicet, Tylox, Vicodin, Lortab, Codeine w/ Tylenol). In published sources the recommended dosing intervals for these products varies from every 4 hours, to 4-6 hours to 6 hours. However, the Agency for Health Care Policy and Research (AHCPR) Clinical Practice Guideline recommends dosing intervals for all these products at q 3-4 hours, an interval more consistent with patient reports of pain relief. (See future Fast Fact for discussion of dosing guidelines for propoxyphene and tramadol products).

Is there a problem with prescribing oral opioids q4-6 or q 6 hours. In the inpatient setting, nursing research from the 1980's indicated that nurses are more likely to administer the minimum drug dose at the longest allowable interval-an order written 1-2 tabs q 4-6, will often result in 1 tab q6h, with inadequate analgesia. In the home setting, patients and families are often excessively concerned about opioid addiction and opioid side effects, so that if the prescription on the bottle says "take every 6 hours", patients are apt to follow this recommendation, even if the pain returns in 2-4 hours.

Is there a danger to more frequent drug administration? There is no danger of dosing intervals as often as every 2 hours for single agent products (e.g., morphine), in patients with normal renal function, as the peak effect will be reached in 60-90 minutes and there is rapid renal excretion. For combination products, the dosing interval should not be less than every 4 hours to avoid excessive acetaminophen (e.g., 2 Percocet tabs every 4 hours = 4 grams acetaminophen/24 hours, the maximum daily recommended dose).

Summary: a) prescribe the products listed above at intervals no greater than every 4 hours; b) provide explicit patient/family counseling regarding safe and allowable dosing intervals.

Suggestion for faculty:
1) the next time you make rounds with housestaff review the admission orders for the above listed products; use this Fast Fact as starting point for discussion of appropriate dosing intervals.
2) check with your hospital Pharmacy committee - ask if there is hospital policy or guidelines for oral opioid doing intervals; if not, such guidelines should be developed.


Fast Facts and Concepts was originally developed as an end-of-life teaching tool by Eric Warm, MD, U. Cincinnati, Department of Medicine. See: Warm, E. Improving EOL care--internal medicine curriculum project. J Pall Med 1999; 2: 339-340.

Contact: David E. Weissman, MD, FACP Palliative Care Program Director Medical College of Wisconsin (P) 414-805-4607 (F) 414-805-4608 [email protected]

Copyright Notice: Users are free to download and distribute Fast Facts for educational purposes only. Citation for referencing: Weissman, D. Fast Fact and Concepts #18: Oral Opioid Dosing Intervals, July, 2000. End-of-Life Physician Education Resource Center www.eperc.mcw.edu.

Disclaimer: Fast Facts provide educational information, this information is not medical advice. Health care providers should exercise their own independent clinical judgment. Some Fast Fact information cites the use of a product in dosage, for an indication, or in a manner other than that recommended in the product labeling. Accordingly, the official prescribing information should be consulted before any such product is used.

Creation Date: 6/2000

Format: Handouts

Purpose: Instructional Aid, Teaching

Training: Fellows, 1st/2nd Year Medical Students, 3rd/4th Year Medical Students, PGY1 (Interns), PGY2-6, Physicians in Practice
Specialty: Anesthesiology, Emergency Medicine, Family Medicine, General Internal Medicine, Geriatrics, Hematology/Oncology, Neurology, OB/GYN, Ophthalmology, Pulmonary/Critical Care, Pediatrics, Psychiatry, Surgery
Non-Physician: Nurses

ACGME Competencies: Medical Knowledge, Patient Care

Keyword(s): Addiction, Adult, Chronic non-malignant pain, Controlled substance regulations, Pain, Pain assessment, Pain treatment

The Fast Facts series is distributed for educational use only and does not constitute medical advice. For the most current version of Fast Facts visit the EPERC web site at www.eperc.mcw.edu. This mirror version is provided subject to copyright restrictions for educational use within the Inter-Instutional Collaborating Network on End-of-Life Care (IICN).