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The Institute for Safe Medication Practices (ISMP), with the knowledge of the FDA, issued an alert about methotrexate overdoses that occur when the drug is incorrectly prescribed or used daily rather than weekly.
Methotrexate is a very old and useful drug for the treatment of various types of cancer. In fact, it is so old that only its generic name is commonly used today, rather than a brand name. It is also approved by the Food and Drug Administration (FDA) for serious, disabling psoriasis...
The Institute for Safe Medication Practices (ISMP), with the knowledge of the FDA, issued an alert about methotrexate overdoses that occur when the drug is incorrectly prescribed or used daily rather than weekly.
Methotrexate is a very old and useful drug for the treatment of various types of cancer. In fact, it is so old that only its generic name is commonly used today, rather than a brand name. It is also approved by the Food and Drug Administration (FDA) for serious, disabling psoriasis and for severe rheumatoid arthritis in adults and children who have not responded to, or cannot tolerate, non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (MOTRIN) or naproxyn (NAPROSYN).
The recommended starting dose for methotrexate in adults for the treatment of rheumatoid arthritis is ONCE WEEKLY, NOT ONCE DAILY.
ISMP gave two examples in their alert to illustrate the serious problems that can result when methotrexate is prescribed incorrectly and is taken daily rather than weekly. In one case, a physician prescribed methotrexate, 15 milligrams daily rather than weekly for a 79-year-old patient. The patient received nine doses before the error was discovered and the patient later died. Another patient died after he misread the directions on a prescription bottle and took 10 milligrams every “morning” instead of every “Monday.”
On January 31, 2003, following a number of medication errors with methotrexate, the Committee on Safety of Medicines (CSM), the British equivalent of the FDA, recommended regulatory action. A new warning statement will be added to the drug’s professional product labeling, cautioning that the drug is usually given once a week.
The CSM also detected an increased number of reports of methotrexate-induced lung toxicity, or pneumonitis, through their national adverse drug reaction reporting system. The CSM recommended that physicians should advise patients of this risk and counsel them to seek medical attention if difficult breathing, a dry nonproductive cough and fever develop.
We certainly agree with this recommendation.
The FDA-approved professional product labeling for methotrexate does contain the following information about lung toxicity, in a black box warning, along with information about a number of other serious adverse reactions:
Methotrexate-induced lung disease is a potentially dangerous lesion, which may occur acutely at any time during therapy and which has been reported at doses as low as 7.5 mg/week. It is not always fully reversible. Pulmonary symptoms (especially a dry, nonproductive cough) may require interruption of treatment and careful investigation. |
Unfortunately, as we have said many times before, there is no requirement that physicians or pharmacists inform patients about potential adverse reactions that may develop with drugs they are taking, or what steps they should take if an adverse reaction develops.
What You Can Do
If you are now taking methotrexate for a disease other than cancer and are taking it daily, check immediately with the prescribing physician about your dosing schedule.
If you experience the lung symptoms described above while taking methotrexate, inform your physician immediately.
