an aqueous solution of sumatriptan or its pharmaceutically acceptable salts thereof in an amount equivalent to 3 mg of sumatriptan base, and sodium chloride in an amount to maintain the osmolality of said solution between 275 to 315 mOsm/kg;
wherein said sumatriptan and sodium chloride are present in a ratio of from about 0.80:1.00 to about 1.40:1.00;
wherein said composition has a pH of about 4.2 to 5.3;
wherein said composition is subcutaneoosly administered to the patient at a maximum recommended frequency according to the body mass index (BMI) of the patient; and
wherein the subcutaneous administration of said composition to the patient results in a systemic exposure characterized by at least one of the following plasma profiles:
c. Cma* of about 35 ng/ml to about 57 ng/ml;
d. AUCo-2 of about 30 ng.hr/ml to about 50 ng.hr/ml;
a. AUQ).jnf of about 43 ng.hr/ml to about 70 ng.hr/ml.
29. The composition of Claim 28, wherein the maximum recommended frequency of administration is not more than four times a day if the BMI is less than about 26.
30. The composition of Claim 28, wherein the maximum recommended frequency of administration is not more than four times a day if the BMI is greater than or equal to about 26.