Megasterol acetate-progestrone derivatives

                                                                                                                                                                                                                             
                                                            MEGESTROL ACETATE

MECHANISM OF ACTION –
On hormone binding the PR undergoes dimerization, attaches to progesterone response element ( PRE ) of target genes and regulates transcription through coactivators.
 It involves the suppression of luteinizing hormone by inhibition of pituitary function.

PHARMACOLOGICAL ACTION –
It converts watery cervical secretion to viscid secretion.
Induces pregnancy like changes in vaginal mucosa.
Proliferation of acini in the mammary glands.
It has a sedative effect.
0.5 0C rise in body temperature.
Exerts negative feedback at the level of hypothalamus.

USES –
1. Contraceptive
2. Hormone replacement therapy
3. Premenstrual tension
4. Habitual abortion
5. Endometrial carcinoma

SIDE EFFECTS –
Anaphylaxis or Anaphylactoid reactions.
Acne
Blood sugar level increases
Amenorrhoea
Edema
Rashes
Urticaria
Atheriosclerosis
Mental depression
Breast tenderness
Pain

DRUG-DRUG INTERACTION –
Megestrol acetate + Abciximab  = therapeutic efficacy of Abciximab can be decreased.
Megestrol acetate + Citric acid  = therapeutic efficacy of Citric acid can be decreased.
Megestrol acetate + C1 Esterase inhibitor ( Human ) = may increase the thrombogenic activities of C1 Esterase inhibitor.

Reference- Tripathi K.D,"Essentials of medical pharmacology"seventh edition,page no-316