Twice-daily medication as effective as more frequent dosing

ByBeth Herskovits

A twice-daily dosing schedule with Alamast may be sufficient to reduce the itching and hyperemia associated with seasonal allergic conjunctivitis, according to one study.

The study compared a twice-daily dosing schedule to four times-daily dosing with Alamast (pemirolast potassium ophthalmic solution, Santen) over 4 weeks.

A simpler dosing regimen may increase patient compliance, the investigators noted.

Petrus Gous, FCS, and Auli M. Ropo, MD, undertook the study at 10 centers in South Africa from September to December 2000.

“September and October are traditionally the most allergenic months of the year in South Africa,” Dr. Gous said.

The study

A total of 169 patients, ranging in age from 6 to 76 years with a positive skin test for seasonal allergic conjunctivitis (at least +2 for both itching and hyperemia), were randomized into two groups.

Investigators conducted clinical evaluations at baseline and at weeks 2 and 4, rating itching and hyperemia on a four-point scale, according to the poster. Patients also recorded their own evaluations of itching and hyperemia in a diary.

At week 2, patients with twice-daily dosing reported a mean reduction of approximately 1.25 in the severity of their itching (on the four-point scale); they also noted a mean reduction in hyperemia of about 1. Patients in the four times-daily group saw a reduction in the severity of itching by a grade of 1.5 and a reduction in hyperemia by a grade of a little more than 1.

At week 4, patients in both the twice-daily and the four times-daily groups reported another 0.5-grade reduction in the severity of their itching. Both groups saw a further reduction in their hyperemia by about 0.25.

The total reductions represented an approximately 50% decrease in the severity of itching and hyperemia for both groups.

Results

Investigators found both regimens to be clinically similar. The mean reductions in itching were statistically similar, while the reductions in hyperemia were comparable. The investigators rated more than 90% of patients in both groups as improved.

While not statistically significant, the investigators did find a greater absolute improvement in four times-daily patients.

“I like the fact that there were no statistically significant differences between the two dosing regimens, but still some difference, leaving physicians with an alternative to adjust the dose. And I found this very important. The four times-daily dosing could be used in patients who don’t respond that well to twice-daily dosing,” Dr. Ropo said.

Complications

Dr. Gous said their nonequivalence study did not categorize patients based on their baseline severity and did not include patients reporting severe reactions.

“Both regimens were well tolerated. There were no statistically significant differences favoring one regimen over the other,” he said.

12% of patients in the twice-daily group and 9% of patients in the four times-daily group reported complications, including infections of the respiratory system and skin. 4% of twice-daily patients experienced vision disorders (aggravated conjunctivitis was the most common at 2%), as did 2% of four times-daily patients (one incident of aggravated conjunctivitis and one of photophobia).

For Your Information:

Petrus Gous, FCS, can be reached at the Pretoria Eye Institute, PO Box 56184, Arcadia, Pretoria, South Africa 0007; +27-12-343-8035; fax: +27-12-343-8038. Dr. Gous has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.

Auli M. Ropo, MD, is director of clinical research and medical affairs at Santen OY. She can be reached at Sornaisten Rantatie 23 (POB 61), Helsinki, Finland FIN-00501; +358-9-5842-4546; fax: +358-9-5842-4460.

Santen Pharmaceuticals can be reached at 555 Gateway Drive, Napa, CA 94588 U.S.A.; +1-707-254-1750; fax: +1-707-254-1769.

References:

Gous P, Ropo A. A comparative trial of the safety and efficacy of 0.1% pemirolast potassium ophthalmic solution dosed twice or four times daily in patients with seasonal allergic conjunctivitis. Poster presentation, Association for Research in Vision and Ophthalmology, Fort Lauderdale, U.S.A., May 2003.