WARNING: This product is for research use only, not for human or veterinary use.
MedKoo CAT#: 100830
Description: Testolactone is discontinued (DEA controlled substance). Testolactone is a progesterone derivative with antineoplastic activity. Testolactone inhibits steroid aromatase, thereby preventing the formation of estrogen from adrenal androstenedione and reducing endogenous estrogen levels.
MedKoo Cat#: 100830
Chemical Formula: C19H24O3
Exact Mass: 300.17254
Molecular Weight: 300.39
Elemental Analysis: C, 75.97; H, 8.05; O, 15.98
Synonym: Fludestrin; therapeutic testolactone. US brand name: Teslac. Abbreviation: TL. Code name: SQ9538.
IUPAC/Chemical Name: (4aS,4bR,10aR,10bS,12aS)-10a,12a-dimethyl-4,4a,4b,5,6,10a,10b,11,12,12a-decahydro-2H-naphtho[2,1-f]chromene-2,8(3H)-dione
InChi Key: BPEWUONYVDABNZ-DZBHQSCQSA-N
InChi Code: InChI=1S/C19H24O3/c1-18-9-7-13(20)11-12(18)3-4-14-15(18)8-10-19(2)16(14)5-6-17(21)22-19/h7,9,11,14-16H,3-6,8,10H2,1-2H3/t14-,15+,16+,18+,19+/m1/s1
SMILES Code: O=C1CC[C@@]2([H])[C@@](CCC3=CC(C=C[C@@]34C)=O)([H])[C@]4([H])CC[C@]2(C)O1
Testolactone, or Teslac (brand name) is an antineoplastic agent that is a derivative of progesterone and is used to treat advanced stage breast cancer. It is nonselective.
TESLACÂ® (testolactone tablets, USP) is available for oral administration as tablets providing 50 mg testolactone per tablet. Testolactone is a synthetic antineoplastic agent that is structurally distinct from the androgen steroid nucleus in possessing a six-membered lactone ring in place of the usual five-membered carbocyclic D-ring. Testolactone is chemically designated as 13-hydroxy-3-oxo-13,17-secoandrosta-1,4-dien-17-oic acid δ-lactone. Inactive ingredients: calcium stearate, cornstarch, gelatin, and lactose. Testolactone is a white, odorless, crystalline solid, soluble in ethanol and slightly soluble in water.
TESLAC is recommended as adjunctive therapy in the palliative treatment of advanced or disseminated breast cancer in postmenopausal women when hormonal therapy is indicated. It may also be used in women who were diagnosed as having had disseminated breast carcinoma when premenopausal, in whom ovarian function has been subsequently terminated. TESLAC was found to be effective in approximately 15 percent of patients with advanced or disseminated mammary cancer evaluated according to the following criteria: 1) those with a measurable decrease in size of all demonstrable tumor masses; 2) those in whom more than 50 percent of non-osseous lesions decreased in size although all bone lesions remained static; and 3) those in whom more than 50 percent of total lesions improved while the remainder were static.
Although the precise mechanism by which testolactone produces its clinical antineoplastic effects has not been established, its principal action is reported to be inhibition of steroid aromatase activity and consequent reduction in estrone synthesis from adrenal androstenedione, the major source of estrogen in postmenopausal women. Based on in vitrostudies, the aromatase inhibition may be noncompetitive and irreversible. This phenomenon may account for the persistence of testolactone's effect on estrogen synthesis after drug withdrawal. Despite some similarity to testosterone, testolactone has no in vivo androgenic effect. No other hormonal effects have been reported in clinical studies in patients receiving testolactone. In one study, testolactone administered orally (1000 mg/day) was reported to increase renal tubular reabsorption of calcium but to have no effect on serum calcium concentration. The mechanism of the hypocalciuric effect is unknown. No clinical effects in humans of testolactone on adrenal function have been reported; however, one study noted an increase in urinary excretion of 17-ketosteroids in most of the patients treated with 150 mg/day orally. Testolactone is well absorbed from the gastrointestinal tract. It is metabolized to several derivatives in the liver, all of which preserve the lactone D-ring. These metabolites, as well as some unmetabolized drug, are excreted in the urine. Additional pharmacokinetic data in humans are unavailable.