A study published today in the Lancet reports that a combination of levonorgestrel 1.5mg with piroxicam is more effective for emergency contraception than levonorgestrel 1.5mg alone.
The currently available oral emergency contraception options levonorgestrel 1.5mg (LNG-EC) and ulipristal acetate 30mg (UPA-EC) act to delay ovulation until sperm from unprotected sex that has already taken place are no longer viable, thus preventing fertilisation. There are not significant post-ovulatory contraceptive effects, therefore LNG-EC and UPA-EC can be effective only if taken early enough in the menstrual cycle to delay ovulation.
A previous study indicates that only about half of pregnancies that would have occurred without use of emergency contraception (EC) are prevented by use of LNG-EC. UPA-EC can be effective until closer to the time of ovulation than LNG-EC and appears to be slightly more effective.
FSRH guidelines indicate that the much more effective copper IUD (Cu-IUD) - which acts to prevent both fertilisation and implantation and is effective even if inserted after ovulation - should be considered first line for EC.
A new study has investigated the effect of using the long-acting cyclo-oxygenase (COX) inhibitor piroxicam in addition to LNG-EC. The rationale for this was that that as prostaglandins support ovulation, fertilisation, tubal function and implantation, COX inhibitors (which inhibit prostaglandin production) could act synergistically with LNG-EC to affect ovulation, and could also have post-ovulatory contraceptive effects.
The full statement is available below to view and download.