The effect of D- versus L-propranolol in the treatment of hyperthyroidism.
The purpose of this study is to determine whether there is a difference in treatment of hyperthyroidism using either the D- or L-isomer of propranolol. Two groups of 20 patients with overt hyperthyroidism received either 120 mg L- or D-propranolol each for a period of 5 days. In the D-propranolol administered group there was a significant decrease in TT3 and fT3 plasma levels and in the ratio of TT3 to TT4; however, a significant increase occurred in rT3 values up to day 5. On the other hand, L-propranolol treatment resulted in a less pronounced decrease in TT4 and TT3 values, while all other thyroid hormone levels remained unchanged as, above all, did the T3/T4 ratio. The well known effect of D,L-propranolol upon peripheral conversion of T4 to T3 is thus not due to the beta-blocking action of L-propranolol but is mainly conditioned by the D-isomer which has no beta-blocking action itself.
Eber
O
O
Department of Internal Medicine, Barmherzige Brüder Graz-Eggenberg Hospital, Austria.
Buchinger
W
W
Lindner
W
W
Lind
P
P
Rath
M
M
Klima
G
G
Langsteger
W
W
Költringer
P
P
D000328:Adult; D000368:Aged; D001481:Basal Metabolism; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011433:Propranolol / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism; D013237:Stereoisomerism; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D014285:Triiodothyronine, Reverse / Q000097:blood
D012738:Sex Hormone-Binding Globulin; D014284:Triiodothyronine; D014285:Triiodothyronine, Reverse; D013972:Thyrotropin; D011433:Propranolol; D013974:Thyroxine