QT Interval Prolongation: Increases in QT interval corrected for heart rate using Fridericia’s formula of ≥60 msec from baseline were measured in 4/162 patients (3%). Administer BESPONSA with caution in patients who have a history of or predisposition to QTc prolongation, who are taking medicinal products that are known to prolong QT interval, and in patients with electrolyte disturbances. Obtain electrocardiograms and electrolytes prior to treatment and after initiation of any drug known to prolong QTc, and periodically monitor as clinically indicated during treatment.
By 1931, estrone, purified from pregnancy urine, placentae , and/or amniotic fluid and for administration via intramuscular injection , was being sold commercially, for instance by Parke-Davis under the brand name Theelin in the United States and by Schering under the brand name Progynon in Germany .     Other products and brand names of purified estrone marketed by 1935 included Oestroform ( British Drug Houses ), Folliculin ( Organon ), and Menformon ( Organon ), as well as Amniotin ( Squibb ).   A partial synthesis of estrone from ergosterol was accomplished by Russell Earl Marker in 1936, and was the first chemical synthesis of estrone.   An alternative partial synthesis of estrone from cholesterol by way of dehydroepiandrosterone (DHEA) was developed by Hans Herloff Inhoffen and Walter Hohlweg in 1939 or 1940,  and a total synthesis of estrone was achieved by Anner and Miescher in 1948.