One-quarter of systemic lupus erythematosus patients in the U.S. taking hydroxychloroquine tablets daily are exceeding the recommended doses for this treatment, and up to one-third of those on alternate-day treatment are forgetting or mixing up their medication, a study reports.
The problem, researchers say, is that only 200 mg tablets exist – and many patients are prescribed a 300 mg dose. New dosage forms are needed to ensure proper treatment, researchers recommend.
The study, “Hydroxychloroquine usage in US patients, their experiences of tolerability and adherence, and implications for treatment: survey results from 3127 patients with SLE conducted by the Lupus Foundation of America,” was published in the journal Lupus Science & Medicine.
The majority of Americans with systemic lupus erythematosus (SLE) are prescribed hydroxychloroquine, called HCQ, a type of disease-modifying anti-rheumatic drug. HCQ may reduce the risk of flares, allow a reduction of the steroids dosage, and protect against organ damage, according to the National Institutes of Health.
Dosing of hydroxychloroquine is based on the patient’s weight, but the treatment is only available in a 200 mg dose. That can make it challenging for physicians to tailor the dose for each individual patient, leading them to sometimes prescribe complex dosing schedules. Some patients take one tablet one day and then two the next, while others may be directed to cut a tablet in half.
To determine if the complex dosing schedules impact how patients take their medication, the Lupus Foundation of America (LFA) conducted a survey examining the tolerability and adherence to hydroxychloroquine in SLE patients. Researchers constructed the online survey, which patients accessed using LFA’s social media channels or through the patient registry. Survey participants in the U.S. were asked about their daily dosage, side effects, and how closely they followed their treatment schedule.
Among the 3,594 people who responded to the survey, 90% had a formal diagnosis of SLE. A large majority (96%) were female. Among the 3,127 patients who were taking hydroxychloroquine, 2,863 provided their current daily dose.
Patients reported an array of gastrointestinal complications, including upset stomach (25%), diarrhea (10%), stomach cramps (6%) and other symptoms (12%).
Overall, 47% of all patients reported experiencing more than one gastrointestinal symptom; this was similar regardless of the dosage. While 56% of all patients experienced gastrointestinal problems, only 15% reported these complications to their physician.
“This suggests that an opportunity may exist for stronger clinician-patient communication regarding symptom management,” investigators said.
Next, researchers asked about complex dosing and its impact on whether patients took HCQ on schedule. Among patients taking alternate-day doses – one 200 mg tablet one day, and then two 200 mg tablets (400 mg) the next – 32% of patients reported forgetting or mixing up their dose.
The problem was markedly less among those taking the same dose every day: 13.6% for those taking 200 mg; 14.2% among those taking one-and-a-half 200 mg tablet; and 14% of those taking two 200 mg tablets.
“This supports the hypothesis that alternating different doses on different days is harder to remember and causes more confusion than taking the same dose each day,” researchers said.
The American Academy of Ophthalmology (AAO) 2016 guidelines recommend that the dose not exceed 5 mg per kilogram of body weight, per day. Researchers calculated the recommended dosage for the 2,696 (75%) participants who provided their body weight.
Results indicated that 26% of these patients were receiving doses that exceeded the maximum recommendation by at least 5%. Therefore, some patients will likely require dose reduction, the researchers said.
Also, 48% of patients taking 1.5 tablets per day – cutting one tablet in half to get the proper dosage – reported a bitter taste when taking HCQ. That result was significantly higher than was reported by patients taking only whole tablets, indicating that the tablet’s coating does not mask its bitter taste once it is cut.
Researchers said the results showed the need for more options than the current 200 mg tablet.
“Availability of new dosage forms of HCQ [hydroxychloroquine] would provide greater flexibility to accurately tailor doses for individual patients, as well as potentially alleviate adherence issues associated with complex HCQ regimens,” investigators concluded.