Contributed by: Dr. Collins E. M. Okoror, MBBS (Ib), MBA, PDip (HRM), FWACS (OBGYN), FMCOG, MPH (RFH)
Consultant Obstetrician and Gynaecologist
Combined oral contraception (COC)
The COCs are an effective form of contraception combining the effect of both the progesterone and oestrogen hormones. Basically, they exhibit their contraceptive effects by inhibiting ovulation, thickening of the cervical mucus and thinning of the endometrium. They should be taken for consecutive days at about the same time of the day. Various forms are available at different proportions of the hormones.
COC containing ≤30 µg of ethinylestradiol (EE) with levonorgestrel (LNG) or noresthisterone (NET) is considered the first choice. Microgynon, a 2nd generation COC, containing 30 µg of EE and 150 µg of LNG, has become the first choice in women requesting COCs.
The second line 2nd generation COC pills include:
- Low strength NET and EE e.g. Loestrin,
- Standard strength NET and EE e.g. Brevinor, and
- Phased COC EE and LNG e.g. Logynon.
The 3rd generation COCs have an increased risk of venous thromboembolism, patients should be assessed and counselled for this when they are being considered. They contain standard strength and low strength of desogestrel (DSG) and EE as first and second lines, respectively. Examples
- Standard strength e.g. Marvelon, Desofem (DSG 150 µg & EE 30 µg)
- Low strength e.g. Mercilon (DSG 150 µg & EE 20 µg).
Initiating COCs
The COCs are best started within the day 1–5 of the cycle. When started after day 5, an additional barrier method of contraception should be used for the first 7 days of initiation. Pregnancy test should be done after 3 weeks if unprotected sexual intercourse (UPSI) has occurred since the last period or if a woman who is amenorrhoeic and with negative pregnancy test has had UPSI in the last 3 weeks.
Switching pills
It is not uncommon to switch pills for perceived or actual adverse effects. Some of the conditions necessitating pills switch include:
Breakthrough bleeding – Before switching brand, check for compliance, exclude pregnancy, drug-drug interaction, infection and local causes of bleeding per vaginam. A switch should be made to the standard strength 2nd generation COC or the 3rd generation COC when the earlier is not available or to the triphasic COC when the earlier two are not available.
Nausea or headache – Pregnancy and eye pathologies should be excluded in these circumstances before switching brands. Where appropriate, a switch should be made to the low strength 2nd generation COC or the low strength 3rd generation COC where the earlier is not available.
Acne, bloatedness, or breast tenderness – A switch should be to the standard strength 3rd generation COC. Where this is unavailable or inappropriate, the client should be referred to the doctor for further evaluation.
Weight gain – Clients should be offered general advice on diet, exercises and being healthy. Where a switch is necessary, it should be to the standard strength 3rd generation COC.
Reduced libido – This may be psychological (e.g., relationship issues, less motivation) and should necessitate a referral to the doctor for evaluation.
Mood swings – Take medical history to determine if the patient is experiencing mood changes all the time or in relation to withdrawal bleed. If it is ascertained that the mood swings are caused by the Microgynon after detailed history, a switch should be made to standard strength 3rd generation COC.
Switching to another brand
When switching pills, the hormone-free interval (HFI) should be omitted, and the new pills commenced the next day i.e. day 22 of the previous pills or within day 1–2 of HFI. If 3–7 hormone-free pills or days are taken, the new brand should be commenced with barrier methods for the first 7 days. It is important to carry out a thorough evaluation of the client before considering a switch to another brand of COC.
Switching to progesterone-only pill (POP)
When switching from COC to POP, it should be started without a break within the day 1–2 HFI or during week 2–3 of COC. When the switch is necessary during week 1 of COC or day 3-7 HFI and in absence of UPSI since start of HFI, additional barrier method should be used for 2 days.
Progesterone-only pills (POP)
The progesterone only contraceptive pills are effective alternatives for clients in whom the oestrogen effects of the COC are undesirable or contraindicated and have no contraindication to the POPs. They have similar mechanisms of action with COC, though at varying degrees. Various forms are available, but the common ones are the NET 350 µg, LNG 30 µg and DSG 75 µg. While NET and LNG administration allows for a 3-hour missed pill window, DSG POP allows a window of 12 hours and is therefore, an option for those who have trouble in complying with stricter dosage regimen of other POPs.
Initiating POP
Like the COC, it is best taken daily at the same time each day beginning from day 1–5 of the cycle. When started after day 5, an additional barrier method of contraception should be used for the first 2 days of initiation. Pregnancy test should be done after 3 weeks if UPSI has occurred since the last period or if a woman who is amenorrhoeic and with a negative pregnancy test has had UPSI in the last 3 weeks.
References
- Faculty of Sexual and reproductive Healthcare (FSRH). Combined hormonal contraception. London, UK: Clinical Effectiveness Unit, FERH; January 2019 (amended July 2019).
- Faculty of Sexual and Reproductive Healthcare (FSRH). Progestogen-only pills. London, UK: Clinical Effectiveness Unit, FSRH; March 2015 (amended April 2019).
- Telford and Wrekin Clinical Commissioning Group. Guidelines for initiation and switching of combined oral contraception. Telford, UK: Telford and Wrekin CCG; December 2016. Available at: https://www.telfordccg.nhs.uk/your-health/medicines-management/prescribing-guidelines/sexual-health-1/2242-oral-contraception-flowchart-and-guidance-v2/file