Off-Label Uses of Medications

APRIL 01, 2005
Kate Kelly, PharmD

The Institute for Safe Medication Practices (ISMP) recently received a call from a patient with "neck pain"who was given a prescription for amitriptyline. When he picked up his prescription, the pharmacist gave him a medication information leaflet, which mentioned, among other points, that the drug was used to treat depression. The leaflet did not mention that the drug might be used to treat neuropathic pain or any other unlabeled indications.

After reading the leaflet, the patient called the pharmacist and asked what the medication was used for. The pharmacist reiterated that the drug often was used for depression. Because the intended purpose of the amitriptyline had not been communicated to the patient or the pharmacist, the patient was quite angry with his physician for "misdiagnosing"his condition. We at ISMP told him that the medication may be used to treat his pain syndrome, and we advised him to call his doctor.

This case is very similar to another report received by ISMP in which an elderly woman was prescribed amitriptyline to treat neurogenic pain syndrome. Her physician did not tell her why it was being prescribed, and he did not write the reason for the medication on the prescription. During counseling, the pharmacist told the patient that the drug usually was prescribed for depression. Subsequently, the patient refused the medication and accused her physician of believing that her pain was all in her head!

Not knowing the purpose of medications also can contribute to diagnostic errors. A recent article (Oto M, Russell A, McGonigal A, Duncan R. Misdiagnosis of epilepsy in patients prescribed anticonvulsant drugs for other reasons. BMJ. 2003;326:326-327) described 2 patients who were prescribed carbamazepine for neuropathic pain without a clear understanding that the medication was intended to treat this condition. After the patients developed blackouts, their treating physicians (who had not prescribed the carbamazepine) inferred from the drug therapy that the patients had epilepsy. Both patients underwent unnecessary diagnostic tests and treatment.

Along with appropriate explanations and instructions to the patient, prescribers should indicate the purpose of each medication on prescriptions, especially for "off-label"uses, as well as for drugs whose names look like or sound like other drug names. For example, a physician should write "take 1 tablet daily for pain."(The Department of Health and Human Services has confirmed that requiring a diagnosis or diagnosis code on a prescription requires no separate special authorization because it falls within the treatment, payment, and health care operations category of the HIPAA privacy rule.)

In addition, pharmacists should ask patients what their physician has told them regarding why they are to use the medication, especially if the drug is used for multiple conditions or often is used "off-label."If a patient is unaware of the condition being treated, consider using a statement such as the following before assuming or stating what the drug is "normally"used for: "This drug could be used for many different conditions, and without knowing the doctor's diagnosis, it is difficult to determine why it was prescribed." Knowing the purpose also helps pharmacists to differentiate drug names that look alike when handwritten poorly or sound alike when spoken. Very few drugs whose names look or sound like others are used for the same purpose.

Dr. Kelly is the editor of ISMP Medication Safety Alert! Community/Ambulatory Care Edition.

Report Medication Errors

The reports described here were received through the USP Medication Errors Reporting Program, which is presented in cooperation with the Institute for Safe Medication Practices (ISMP). ISMP is a nonprofit organization whose mission is to understand the causes of medication errors and to provide time-critical error-reduction strategies to the health care community, policy makers, and the public. Throughout this series, the underlying system causes of medication errors will be presented to help readers identify system changes that can strengthen the safety of their operation.

If you have encountered medication errors and would like to report them, you may call ISMP at 800-324-5723 (800- FAILSAFE) or USP at 800-233-7767 (800-23-ERROR). ISMP's Web address is

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