PHARMACIST CORNER

PHARMACIST CORNER 2017-10-02T16:56:44+00:00

Methadone

Methadone has the ability to relieve a wide variety of pain types, is available in a “long acting” 10 mg/ml concentration, and it is low cost. All of these reasons make it an ideal analgesic for hospice. Many nurses and medical directors may be reluctant to use methadone because of its complex metabolism and their unfamiliarity with it.

A few simple facts about methadone can help build a foundation of understanding:

  1. Methadone is VERY lipophilic. The amount of fat on a patient determines the dosing frequency, speed of titration, and time to reach full therapeutic effect. It is also important to be extra diligent in watching for signs of overdose as a patient loses weight and methadone is released from fat cells.
  2. The process of switching from one opioid to methadone can be a slow process. It may take up to four weeks depending on their previous opioid dose and the weight of the patient (see above).
  3. Never start or increase methadone on a Friday. The best time to start methadone is at the beginning of the week to ensure the patient is monitored carefully.
  4. There are many drug interactions with methadone. Once methadone is started, many common hospice medications should not be used (e.g., Phenobarbital, Cipro, Prozac, Macrobid, Zoloft, Diflucan). Consult a pharmacist when adding any new medication to a patient’s drug regimen.
  5. Methadone overdose is reversible with naltrexone dosed IV, SQ, or IM. Multiple doses given over a few hours may be required.

When switching to methadone, consult a HospiceMed pharmacist and have the following information ready: total daily dose of all opioids, patient weight, and patient and family pain goals. The HospiceMed pharmacist will work together with the Case Manager to create a pain management plan to successfully convert the patient to methadone.

Over time, with each patient successfully managed on methadone and with the help of a knowledgeable pharmacist, both nurses and medical directors can become comfortable using methadone regularly in their hospice practice.

Resources:

American Pain Foundation. http://www.painfoundation.org
American Association for Cancer Pain Initiative. http://www.aacpi.org
American Chronic Pain Association. http://www.theacpa.org
Drug Information Handbook. 13th ed. (2005) Hudson, Ohio: Lexi-Comp Inc.
Goodman & Gilman’s The Pharmacological Basis of Therapeutics. 10th ed. (2002). New York, NY: McGraw Hill.
Partners Against Pain. http://www.partnersagainst pain.org
Manfredonia, John F. (2005). Prescribing methadone for pain management in end-of-life care. JAOA: Journal of the American Osteopathic Association. 105.3 supplement: 18S.
Yazdanbakhsh, Arash, et al. (2016). Comparison of Effects and Side Effects of Two Naloxone-Based Regimens in Treatment of Methadone Overdose. Iranian Journal of Toxicology Vol 10.1.