Introduction

Emergency contraception is clinically indicated for women who do not wish to conceive following unprotected sexual intercourse (UPSI).

Pharmacists are ideally placed to provide patients with advice regarding emergency contraception (EC) and easy access to EC through community pharmacies, either through OTC sale or supply under a PGD, helps to reduce the risk of an unplanned pregnancy.

Emergency contraception has been available through community pharmacy since 2001 when levonorgestrel was switched from POM to P. Levonorgestrel is licensed for use within 72 hours of UPSI or contraceptive failure. Ulipristal was launched as an OTC product in 2009. It is licensed as EC for use within 5 days (120 hours) after UPSI or contraceptive failure.

In order for pharmacists to provide accurate advice to patients it is important that they remain up to date with current clinical advice.

Updated Guidance

The Faculty of Sexual and Reproductive Health (FSRH) launched updated Emergency contraception guidelines in March 2017[1].

Key changes in this updated guidance include:

• Ulipristal is more effective oral emergency contraceptive than levonorgestrel
• Oral emergency contraception may be less effective in women with a higher BMI

 This article will focus on these key changes and the evidence behind the updated guidance.

Emergency Contraception

Every woman requesting advice over emergency contraception should be advised that the most effective method of emergency contraception is a copper containing Intra Uterine Device (Cu-IUD).

A Cu-IUD should be fitted within 5 days of UPSI or ovulation. A 2012 review reported a pregnancy rate of less than 0.1%[2] after insertion of a Cu-IUD. This method of EC has the added benefit that if left in place the IUD will provide effective ongoing contraception, it is also not affected by other drugs or BMI.

The FSRH guideline advises all EC providers that if they refer women for insertion of a Cu-IUD that they should also provide oral EC at the time of referral in case she either changes her mind or a Cu-IUD cannot be inserted.

Ulipristal is more effective oral emergency contraception than levonorgestrel

When considering the potential risk of pregnancy and the most appropriate choice of EC it is important to remember that the risk of pregnancy is highest in the 5 days prior to ovulation in addition to the day of ovulation, UPSI during this fertile time poses a pregnancy risk of up to 30%[3]

In order to understand the assertion that ulipristal is a more effective oral emergency contraceptive than levonorgestrel it is important to consider the differing mechanisms of action of the two drugs.

Levonorgestrel is a synthetic progestogen. The effectiveness of levonorgestrel EC declines during the cycle. When taken before the luteinising hormone (LH) surge it prevents ovulation for the next five days, whilst if taken after the surge begins or following ovulation levonorgestrel EC becomes ineffective.

The pregnancy rate in women taking levonorgestrel within 72 hours of UPSI is quoted as between 0.6-2.6%¹. In these studies levonorgestrel was taken at any time of the cycle, consequently it is impossible to predict whether these women would have been at risk of pregnancy or not.

Ulipristal is a selective progesterone receptor modulator. It acts to delay ovulation for at least 5 days; ulipristal will delay ovulation after the start of the luteinising hormone surge whilst levonorgestrel will be no longer effective at this stage. Ulipristal, like levonorgestrel, cannot inhibit ovulation after the LH peak.

The pregnancy rate after administration of ulipristal is reported as 1-2%¹. This does not take into account the timing of the ulipristal administration so it would not be accurate to advise a patient taking ulipristal just prior to ovulation that there is only a 1-2% chance of pregnancy as this would be considered the most risky time for UPSI.

The FSRH have reviewed the available data on oral emergency contraception and concluded that ulipristal is more effective as EC than levonorgestrel.

FSRH also advise that all providers of EC should advise women that oral methods of EC do not provide contraceptive cover for subsequent UPSI. Many women will ovulate following EC use and should be advised to use effective contraception or abstain from sexual intercourse to avoid a risk of pregnancy.

Oral emergency contraception may be less effective in women with a higher BMI

The FSRH guidance advises that the efficacy of the Cu-IUD is not affected by patient weight or BMI. Some studies have suggested that levonorgestrel and ulipristal EC may be less effective in women who are overweight or obese. The negative impact of increasing weight on efficacy is higher with levonorgestrel based EC than ulipristal EC¹.

Studies have shown that ulipristal EC could be less effective for women weighing more than 85kg or with a BMI exceeding 30kg/m², whilst increased pregnancy rates following levonorgestrel administration have been shown in women weighing more than 70kg or with a BMI exceeding 26kg/m².

The FSRH development group concluded that women weighing more than 70kg or with a BMI above 26kg/m² should be advised that a Cu-IUD is the most effective option for EC¹. Where a Cu-IUD is not indicated or acceptable the oral EC of choice would be ulipristal. If ulipristal is not suitable a double dose (3mg) of levonorgestrel could be used. The double dose would be outside of the product license and consequently would require the patient to be referred to their GP or sexual health provider.

Advice

In addition to the updated guidance all pharmacists should ensure that patients enquiring about emergency contraception are advised about:

 

• ongoing contraception including
  • contraceptive options available to the patient,
  • where the patient can access contraception,
• the risk of sexually transmitted infections and testing procedures
• requirement for pregnancy testing

 Summary

 The FSRH guidelines can be summarised as:

• Copper IUDs remain the most effective and consequently first line option for emergency contraception
• Ulipristal is the first line oral EC for any woman who asks for advice following UPSI in the five days prior to ovulation, more than 3 days previously or who are overweight.
• Levonorgestrel will remain first line option where the woman wants to start hormonal contraception quickly, if she is at risk of pregnancy following missed oral contraceptive pills or is taking enzyme inducing medication.