Fludestrin: Full Drug Profile

Fludestrin - General Information

An antineoplastic agent that is a derivative of progesterone and used to treat advanced breast cancer. [PubChem]

Pharmacology of Fludestrin

Fludestrin is a synthetic anti-neoplastic 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. 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.

Fludestrin for patients

The physician should be consulted regarding missed doses. Notify the physician if adverse reactions occur or become more pronounced.

Fludestrin Interactions

When administered concurrently, testolactone may increase the effects of oral anticoagulants; monitor and adjust anticoagulant dosage accordingly.

Drug/Laboratory Test Interactions:   Physiologic effects of testolactone may result in decreased estradiol concentrations with radioimmunoassays for estradiol, increased plasma calcium concentrations, and increased 24-hour urinary excretion of creatine and 17-ketosteroids.

Fludestrin Contraindications

Testolactone is contraindicated in the treatment of breast cancer in men and in patients with a history of hypersensitivity to the drug.

Additional information about Fludestrin

Fludestrin Indication

For palliative treatment of advanced breast cancer in postmenopausal women.

Mechanism Of Action

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 vitro studies, 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.

Generic Name

Testolactone

Synonyms

Testolactona [Inn-Spanish]; Testolactonum [Inn-Latin]; Testolattone [Dcit]

Drug Category

Antineoplastic Agents, Hormonal

Drug Type

Small Molecule; Approved

Other Brand Names containing Testolactone

Fludestrin; Teolit; Teslac; Teslak; Testolacton;

Absorption

Testolactone is well absorbed from the gastrointestinal tract.

Toxicity (Overdose)

Oral LD₅₀s in mouse and dog are 1630 mg/kg and 593-926 mg/kg, respectively.

Protein Binding

~85%

Biotransformation

Hepatic. Metabolized to several derivatives in the liver, all of which preserve the lactone D-ring.

Dosage Forms of Fludestrin

Tablet Oral

Chemical IUPAC Name

(4aS,4bR,10aR,10bS,12aS)-10a,12a-dimethyl-4,4a,4b,5,6,10b,11,12-octahydro-3H-naphtho[6,5-f]chromene-2,8-dione

Chemical Formula

C19H24O3

Organisms Affected

Humans and other mammals