Rosacea treatments: Delayed-release doxycycline 40 mg and doxycycline 100 mg face off

July 1, 2008

Study shows comparable efficacy and onset of therapeutic effect with doxycycline 40 mg (delayed release) once daily or doxycycline 100 mg once daily for treatment of rosacea, with some differences in adverse effects.

Key Points

Adverse effects

However, doxycycline 40 mg delayed-release showed a significant benefit in its safety profile, as those patients who received doxycycline 100 mg had a much more frequent association with adverse events, especially gastrointestinal side effects.

Efficacy endpoints included both inflammatory lesion reduction and investigator global assessment. The difference in therapeutic onset was also found to be comparable in both of the treatment arms.

Gastrointestinal side effects were reported exclusively in the study arm treated with doxycycline 100 mg once daily, and included esophageal pain, nausea, diarrhea and abdominal pain.

Conclusions

"This study demonstrates that the branded doxycycline 40 mg delayed-release formulation once daily is as effective for rosacea as doxycycline 100 mg once daily, and with the same onset of therapeutic action.

"Importantly, doxycycline 100 mg once daily produced a significantly higher rate of adverse events, especially gastrointestinal side effects," says James Q. Del Rosso, D.O., dermatology residency director, Valley Hospital Medical Center in Las Vegas.

Dr. Del Rosso says both the number of adverse events and the number of patients with adverse events was greater in the doxycycline 100 mg group.

Dr. Del Rosso tells Dermatology Times that compared to doxycycline 100 mg once daily, doxycycline 40 mg, delayed release, administered as one capsule daily is a superior treatment for papulopustular rosacea, and augments results achieved with topical therapy.

Though the efficacy and onset of activity of doxycycline 100 mg is the same, 40 mg delayed-release doxycycline offers significantly better tolerability, a lack of antibiotic activity and, importantly, does not contribute toward antibiotic resistance, one of the emerging problems seen with chronic oral antibiotic therapy for disorders such as rosacea.

Risk-benefit analysis

According to Dr. Del Rosso, the results show that the risk-benefit analysis favors doxycycline 40 mg, delayed release, over doxycycline 100 mg, making it the preferred oral therapy choice in the treatment of rosacea.

"Another advantage of the once- daily doxycycline 40 mg delayed-release formulation is the proven lack of antibiotic activity, as opposed to doxycycline 100 mg once daily, which has been shown in a recent study to produce emergence of resistant bacterial strains within one week of use.

As rosacea has no proven bacterial cause, an antibiotic effect is not needed when treating rosacea, and may be considered an unwanted byproduct of doxycycline when used in a dosage that produces an antibiotic effect.

"This is especially important, as the chronicity of rosacea warrants long-term treatment," Dr. Del Rosso says.