Combined Oral Contraceptive (Follow-up and Common Problems)

• When the patients attend for follow-up ask:
  • Has she found it easy to use?
  • Has she noticed any adverse effects?
  • Does she understand how to take it?
  • Does she know how to manage missed pills?¹
  • Has the pattern of withdrawal bleeds been regular?
  • Has there been any breakthrough bleeding?
• At future appointments e.g. annual review, consider whether contraception is still required and if the combined pill is still the most appropriate and safest method:
  • Have there been developments in her medical history e.g. new medication or social history e.g. age and smoking, which need to be considered.
  • Check blood pressure.
  • Check whether cervical screening is due.
  • Give the patient opportunity to ask questions.

Breakthrough bleeding

See also separate article on breakthrough bleeding. Women should be advised that this can occur with the combined oral contraceptive pill (COCP), most commonly in the first few months.
If there has been no vomiting or diarrhoea and no missed pills, it has not been shown to indicate reduced efficacy.
If a patient presents with breakthrough bleeding (BTB) consider the following before a change of pill:

• Test for chlamydia. Chlamydial cervicitis is the most common cause of BTB in young sexually active women.²
• Look for local causes i.e. examine the cervix.
• Have there been any missed pills? BTB may start 2-3 days after a missed pill.
• Is the patient taking any other medicines? Enzyme inducers e.g. rifampicin, carbamazepine, St John's Wort.
• Does the patient drink? People who drink heavily are more likely to miss pills and less likely to remember that they have.
• Is there any reason to suggest an absorption problem? Has there been diarrhoea or vomiting?
• Is the patient pregnant or recently lost a pregnancy?
• Does the patient have a bleeding tendency?

Bleeds or spotting at times other than the expected withdrawal bleed which persists for more than 3 months should be managed by changing the type of pill.
There is limited data to suggest that BTB is more common with preparations containing 20 micrograms of oestrogen rather than 30 or higher. A Cochrane review found little evidence supporting bi-phasic or tri-phasic preparations, and suggested that choice of progestogen may be more important.³

Drug interactions

There are many commonly used drugs which can affect the efficacy of the pill:

• Antibacterials - rifamycins, amoxicillin and tetracyclines
• Antidepressants - St John's Wort (which can be bought over the counter)
• Anti-convulsants - carbamazepine, oxcarbazepine, phenobarbital, phenytoin, primidone and topiramate
• Anti-fungals - griseofulvin
• Anti-virals - nelfinavir, nevirapine, ritonavir
• Modafinil (used in the treatment of narcolepsy and fatigue)

Erythromycin, co-trimoxazole and sulphonamides are thought not to interact with the pill.
Long-term antibiotics are less likely to effect pill use as resistant gut flora emerge after 3 weeks.
The anti-convulsants sodium valproate and lamotrigine are also thought to have little effect on pill efficacy.

Diarrhoea and vomiting

• Vomiting within 2 hours of taking the pill or very severe diarrhoea can affect the absorption of the pill.
• The advice for women who suffer vomiting or diarrhoea for more than 24 hours is to follow the same advice as if they had missed pills.
• Women should be advised to carry out a pregnancy test and seek medical advice if there is a very light or no withdrawal bleed

Surgery

For any woman on the COCP about to undergo major elective operation, or leg surgery, the risk of thromboembolism needs to be balanced with the risk of unwanted pregnancy.⁵

Amenorrhoea

• There can be amenorrhoea following cessation of using the COCP. This is usually due to the pill's withdrawal bleeds masking an underlying problem.
• Any amenorrhoea lasting more than 6 months after stopping the pill should be investigated as for secondary amenorrhoea.

Mature women

Advice for Women over 40 years of age:

• Women should be advised that although natural fertility declines after 37 years of age, effective contraception is still required.
• No contraceptive method is contraindicated by age alone.
• The COCP can be used unless there are coexisting diseases or risk factors.
• Women who have no other risk factors, and have stopped smoking more than 1 year ago, may use the COCP.
• Clinicians prescribing the pill to women over 40 years should consider a monophasic pill, with less than, or equal to 30 micrograms of oestrogen and a low dose of norethisterone or levonorgestrel as the first choice.
• There is debate over evidence showing a potential protective effect against osteoporosis. Low dose preparations with 30-35 micrograms of oestrogen may positively affect bone mineral density.

Menorrhagia

• In women with heavy, painful menses the combined pill has been shown to reduce the amount of pain and bleeding.^6,7
• It can also make the cycle more manageable by running together packs, and avoiding the pill-free week, women can avoid the withdrawal bleed. This is particularly useful for travel, but also for athletes. It is good practice to advise women that they can manipulate their cycle in this way as research has suggested that 78% of women are not aware of this potential and 58% of women would be interested in using this option.⁸

Polycystic ovarian disease

• Women who have polycystic ovarian disease (PCOS) are often oligo-amenorrhoeic.
• Endometrial cystic hyperplasia is associated with prolonged periods of anovulation, as found in PCOS.
• There is an association between endometrial carcinoma in young women, aged less than 40 years and PCOS.⁹ They should be offered protective therapy from prolonged exposure to relatively unopposed oestrogen. The COCP does this effectively, as well as providing contraception.

Acne

• Randomised controlled trials have shown significant improvements in acne vulgaris whilst using the COCP.
• This evidence is specific for preparations containing the progestogens levonorgestrel and norethisterone. There is no evidence to support the use of Cilest® or Yasmin® for this purpose. Dianette® is also indicated for use in acne or moderately severe hirsutism. It should be withdrawn if there is no improvement after 3 months of use. Dianette® carries a four times higher risk of VTE than other COCPs and should not be used indefinitely.

Risk of ovarian or endometrial cancer

• The pill has been shown to reduce the risk of ovarian or endometrial cancer in those considered to be at risk because of family history.
• The risk is reduced by 50% in ovarian cancer if the COCP is used for more than 5 years, or 50% in endometrial cancer if used for more than 1 year.