Contraceptive applications of progesterone receptor modulators

Leiomyoma treatment by uterine artery embolization using gelatin sponge prepared by the pumping method

Uterine leiomyoma, a benign tumor, may be treated with drugs, albeit surgical resection is more common. The present study aimed to evaluate the treatment of leiomyoma cases by uterine artery embolization (UAE) using a gelatin sponge prepared by the pumping method. The results of 700 leiomyoma cases treated by UAE in the outpatient department were evaluated. UAE was performed by injecting gelatin sponge prepared by the pumping method into the uterine artery. Among 700 cases, effective cases were 680 (97.2%), ineffective cases were 18 (2.8%) and impossible cases for UAE were 2 (0.2%). Retreatment was required in 23 cases (3.3%). Complication events designated by the Society of Interventional Radiology Clinical Practice Guidelines occurred in 31 cases (4.4%): 1 case showed permanent adverse sequelae, 4 cases required major therapy with a prolonged hospitalization (>48 h) and 10 patients required therapy with minor hospitalization (<48 h). The remaining 16 cases required nominal or no therapy. Follow-up of patients was performed for 599 cases for an average period of 1.2±0.9 years, ranging between 1 month and 6 years. Pregnancy after UAE was observed in 12 cases/15 cycles. Thus, the findings indicate that UAE using gelatin sponge prepared by the pumping method applied to outpatients is a safe and useful treatment procedure.

Contraceptives with novel benefits

INTRODUCTION

Progesterone receptor (PR) agonists (progestins) and antagonists are developed for female contraceptives. However, non-contraceptive applications of newer progestins and PR modulators are being given more attention.

AREAS COVERED

The newer PR agonists including drospirenone, nomegestrol, trimegestone, dienogest and nestorone are being evaluated as contraceptives with health benefits because of their unique pharmacological properties. The selective PR modulators (SPRM; PR antagonists with PR agonistic properties) are under development not only for emergency contraception but also for other health benefits such as the treatment of endometritis and leiomyoma. After searching the literature from PubMed, clinicaltrials.gov and patent database, this review focuses on the effects and mechanisms of these progestins, and SPRMs as contraceptives with other health benefits.

EXPERT OPINION

PR agonists and antagonists that have novel properties may generate better contraceptive effects with other health benefits.

The state-of-the-art of emergency contraception with the cutting edge drug

The objective of this study is to evaluate and elucidated the potential of selective progesterone receptor modulators (SPRMs) to be an effective emergency contraception (EC). The data are extracted from the literature through the MEDLINE database service from 2000-2010. The SPRMs are in fact progesterone receptor ligands that could bind to progesterone receptor (PR) and exert antagonistic, agonistic or mixed agonist-antagonistic effects. These SPRMs are mifepristone, onapristone, asoprisnil, ulipristal, proellex among other compounds. Currently developed SPRMs may exert contraceptive effects by inhibiting ovulation and retarding endometrial synchronization. Low-doses of progesterone antagonists retard endometrial maturation without affecting ovulation. Mifepristone being a SPRM is effective for prevention of pregnancy but with prostaglandin acts as an excellent abortifacient; yet could not compete with levonorgestrel as EC. However, a single dose of 30 mg ulipristal acetate, another SPRM with similar effectiveness and side effect profiles as 1.5 mg levonorgestrel EC, has shown wider 'window of effect' by inhibition of the LH peak even if administered at the advanced pre-ovulatory phase, a time when use of levonorgestrel EC is no longer effective. Thus, ulipristal acetate goes one-step ahead of levonorgestrel in the field of emergency contraception treatment. Further studies are needed to explore the potential of other SPRMs to be cutting edge emergency contraceptive drugs.