Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to the rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

Adverse Reactions in Short-term Studies

The safety of tranexamic acid USP tablets in the treatment of heavy menstrual bleeding in females of reproductive potential was studied in two randomized, double-blind, placebo-controlled studies [see Clinical Studies (14)]. 

  * Study 1 compared the effects of two doses of tranexamic acid USP tablets (1950 mg and 3900 mg per day for up to 5 days during each menstrual period) versus placebo over a 3-cycle treatment duration. A total of 304 women were randomized to this study, with 115 receiving at least one dose of 3900 mg/day of tranexamic acid USP tablets.
  * Study 2 compared the effects of tranexamic acid USP tablets (3900 mg/day) versus placebo over a 6-cycle treatment duration. A total of 196 women were randomized to this study, with 117 receiving at least one dose of tranexamic acid USP tablets.



Across the studies, the combined exposure to 3900 mg/day tranexamic acid USP tablets was 947 cycles and the average duration of use was 3.4 days per cycle. In both studies, subjects were generally healthy women who had menstrual blood loss of ≥ 80 mL. In these studies, subjects were 18 to 49 years of age with a mean age of approximately 40 years, had cyclic menses every 21-35 days, and a body mass index (BMI) of approximately 32 kg/m 2. On average, subjects had a history of heavy menstrual bleeding for approximately 10 years and 40% had fibroids as determined by transvaginal ultrasound. Approximately 70% were Caucasian, 25% were Black, and 5% were Asian, Native American, Pacific Islander, or Other. Seven percent (7%) of all subjects were of Hispanic origin. Women using hormonal contraception were excluded from the trials. 

A list of adverse reactions occurring in ≥ 5% of subjects and more frequently in tranexamic acid USP tablets-treated subjects receiving 3900 mg/day compared to placebo-treated subjects is provided in Table 2.

Adverse Reactions in Long-term Studies

Long-term safety of tranexamic acid USP tablets was studied in two open-label studies. In one study, subjects with physician-diagnosed heavy menstrual bleeding (not using the alkaline hematin methodology) were treated with 3900 mg/day for up to 5 days during each menstrual period for up to 27 menstrual cycles. A total of 781 subjects were enrolled and 239 completed the study through 27 menstrual cycles. A total of 12.4% of the subjects withdrew due to adverse reactions. Women using hormonal contraception were excluded from the study. The total exposure in this study to 3900 mg/day tranexamic acid USP tablets was 10,213 cycles. The average duration of tranexamic acid USP tablets use was 2.9 days per cycle.

A long-term open-label extension study of subjects from the two short-term efficacy studies was also conducted in which subjects were treated with 3900 mg/day for up to 5 days during each menstrual period for up to 9 menstrual cycles. A total of 288 subjects were enrolled and 196 subjects completed the study through 9 menstrual cycles. A total of 2.1% of the subjects withdrew due to adverse reactions. The total exposure to 3900 mg/day tranexamic acid USP tablets in this study was 1,956 cycles. The average duration of tranexamic acid USP tablets use was 3.5 days per cycle.

The types and severity of adverse reactions in these two long-term open-label trials were similar to those observed in the double-blind, placebo-controlled studies although the percentage of subjects reporting them was greater in the 27-month study, most likely because of the longer study duration.

A case of severe allergic reaction to tranexamic acid USP tablets was reported in the extension trial, involving a subject on her fourth cycle of treatment, who experienced dyspnea, tightening of her throat, and facial flushing that required emergency medical treatment.