ANTI NEOPLASTIC AGENTS
“STEROIDS & HORMONES”
Content
• Structure, Therapeutic Use, Mechanism of Action of
Dromostanolone
• Structure, Therapeutic Use, Mechanism of Action of MEGESTROL
I.
DROMOSTANOLONE
• It is a synthetic anabolic steroid that has antiestrogenic
effects.
• It is related to dihydrotestosterone.
14-hydroxy-2,4,15-trymethyl tetracyclo-heptadecan-5-one.
Therapeutic Use of DROMOSTANOLONE:
• It is marketed as Drostanolone propionate and its use has
been restricted to treatment of metastatic carcinoma of breast.
Mechanism of Action of
DROMOSTANOLONE:
• It interacts
with the Androgen receptor and modifies gene transcription in presence of co-activators and
co-repressors, including increased
protein synthesis (anabolism)
and decreased amino acid degradation (catabolism).
• It also
induces a reduction or inhibition of prolactin or estrogen receptors in the breasts, which indicates
anti tumour effects.
II. MEGESTROL
• It is a synthetic derivative of progesterone with
antiestrogenic activity.
• 17-acetyl-17-hydroxy-6,10,13-trimethyl-2,8,9,11,12,14,15,16-octahydro-1H-cyclopenta[a]phenanthren-3-one.
Mechanism
of Action of MEGESTROL:
• Megestrol
binds to and activates nuclear receptors which subsequently bind to and
activate target genes for transcription.
• As an
antiestrogen, this agent may inhibit the growth-stimulating effects of estrogen
on estrogen-sensitive tumor cells.
• Antitumour
activity may involve suppression of luteinizing hormone by inhibition of
pituitary function.
• In addition,
megestrol stimulates appetite in cachectic subjects.
Therapeutic
Uses of MEGESTROL:
• It is marketed as Megestrol acetate and
is indicated for the
palliative treatment of advanced carcinoma of the breast or endometrium.
• Megestrol acetate Oral Suspension USP is indicated for the treatment of anorexia,
cachexia, or an unexplained, significant weight loss in patients with a
diagnosis of acquired immunodeficiency syndrome (AIDS).
SUMMARY
• Dromostanolone is a synthetic anabolic steroid that has antiestrogenic
effects used in the treatment of breast cancer.
• It acts by binding to the Androgen receptor thereby
generating cascade of genetic changes.
• Megestrol is a synthetic derivative of progesterone with
antiestrogenic activity used in the treatment of breast and endometrium cancer.
• It acts by inhibiting the growth-stimulating effects of estrogen on estrogen-sensitive tumor
cells.