Medication Errors Associated with Flomax and Volmax
Problem: Medication errors have been reported involving Flomax and Volmax due to the look alike and sound alike proprietary names and similar dosage strengths. Flomax was approved on April 15, 1997 and is indicated for the treatment of signs and symptoms of benign prostatic hyperplasia. Volmax was approved December 23, 1992 and is indicated for relief of bronchospasm. The dosage strengths differ by one decimal point, where Flomax is available as 0.4 mg capsules and Volmax is available as 4 mg and 8 mg Extended-Release Tablets. Boehringer Ingelheim manufactures Flomax and Muro Pharmaceuticals manufactures Volmax. The container labels are not similar, but both are available in 100 count bottles (Flomax is also available in 500 count bottles and Volmax in 1000 count bottles). The proprietary names look alike and sound alike to each other. Such similarities between Flomax and Volmax increase the potential for medication errors.
The following table summarizes the medication error reports received by the FDA since 1997, four of which were received in 1999.
Postmarketing Safety Reports of Medication Errors Associated with Flomax and Volmax
|Intended product as written or stated||Dispensed product/ intended to dispense||Outcome||Cause(s)|
|Volmax||Flomax||No adverse outcome. The error was detected prior to dispensing.||Verbal miscommunication|
|Volmax 4mg||Flomax 0.4mg||No adverse outcome. The patient discovered error prior to administration.||Verbal miscommunication|
|Flomax 0.4mg||Volmax 4mg||Potential error reported by the pharmacist, who stated because of the handwriting the prescription could have easily been misinterpreted.||Illegible handwriting|
|Volmax||Flomax 0.4mg||Insomnia, tiredness, weakness, dizziness, runny nose, frequent urination, chronic sinus infection (underwent surgery), polyp on vocal cord (underwent surgery).||Verbal miscommunication|
|Flomax 0.4mg||Volmax 4mg||No adverse outcome. The error was detected prior to patient administration.||Doctor prescribed incorrect medication due to name confusion|
|Volmax||Flomax||Unknown||Verbal miscommunication and dosage strength confusion|
The errors that have been reported were due to name confusion and dosage similarity. Five of the six cases resulted from the miscommunication of a verbal order, four of which were discovered prior to patient administration and one of which was a potential error.
The one case in which a patient experienced an adverse outcome occurred when a 50 year-old female patient was prescribed Volmax, however the prescription was incorrectly filled with Flomax capsules. The error occurred during the transcription of the verbal prescription by the pharmacist. The medication was administered for several months until she returned to her physician and reported the medication was not effective. The patient complained of insomnia, tiredness, weakness, dizziness, runny nose, frequent urination and chronic sinus infection. The patient was hospitalized and underwent surgery for the chronic sinus infection. During that time, a polyp was discovered on her vocal cord and was surgically removed.
Recommendation: Limit verbal orders for these two drug products whenever possible. When receiving a verbal prescription, ask the prescriber to spell the name and/or ask for the indication of the medication. In addition, request a fax copy of the order. Also, practitioners should include a preceeding zero when stating or writing the strength of Flomax (0.4 mg). This may help reduce transcribing and processing errors due to illegible handwriting. Furthermore, being familiar with the patients’ medical history may allow pharmacists to detect the name confusion before the actual error occurs.