Kombinierte Antibabypille - Nachsorge und häufige Probleme

Good practice for the first prescription of the combined oral contraceptive (COC) pill is described in the separate article Combined oral contraceptive pill -first prescription). This article covers good practice for follow-up, safe ongoing prescribing and issues which may be encountered in doing so.

When to follow up

After the first prescription, review at three months. If all is well, follow up at 6- to 12-monthly intervals. Supplies of up to a year may be issued.

Stress to the woman that she should return earlier if she develops any problems or side-effects, or if she has any concerns.

• Ask:

  • Has she found it easy to use/remember?

  • Has she noticed any adverse effects?

  • Does she understand how to take it?

  • Does she know how to manage missed pills?

  • Has the pattern of withdrawal bleeds been regular?

  • Has there been any breakthrough bleeding (BTB)?

  • Have there been developments in her medical history (for example, new medication) or social history (for example, age and smoking) which need to be considered.

  • Is she happy with the pill, or would she prefer a long-acting method (which have lower real-life failure rates)?

• Examination:

  • Check blood pressure.

  • Measure Körpermasseindex (BMI).

• Consider whether contraception is still required and if the combined pill is still the most appropriate and the safest method.

• Check whether cervical screening is due.

• Give the patient the opportunity to ask questions

Breakthrough bleeding (BTB)

Siehe den separaten Artikel Zwischenblutungen bei kombinierter hormoneller Empfängnisverhütung. Women should be advised that this can occur with COC, most commonly in the first few months. If there has been no vomiting or diarrhoea and there have been no missed pills, it has not been shown to indicate reduced efficacy. Consider sexually transmitted infections, pregnancy, missed pills, and malabsorption as possible causes, but BTB is a common side-effect.

Gewichtszunahme

Cochrane reviews have consistently failed to show any evidence that significant weight gain is a side-effect of the pill.¹²

Wechselwirkungen

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

• Antibacterials - enzyme inducers only (for example, rifampicin, rifabutin).

• Complementary therapy - St John's wort (which can be bought over the counter).

• Anticonvulsants - carbamazepine, oxcarbazepine, eslicarbazepine, phenobarbital, phenytoin, primidone and topiramate, due to their enzyme-inducing activity. Also lamotrigine which has a specific safety warning - there is an increased risk of seizure whilst taking COC with lamotrigine, and a risk of toxicity during the pill-free week, when levels rise. Therefore, risk may outweigh benefit (UKMEC category 3).

• Antiretrovirals - in particular, ritonavir-boosted protease inhibitors.

Women on medication which may interact with the contraceptive pill should be advised to carry out a pregnancy test and seek medical advice if there is a very light or no withdrawal bleed. They should also seek advice if they have BTB, which may indicate reduced efficacy in this situation.

Other medications may cause lack of efficacy of the contraceptive pill by causing side-effects such as diarrhoea or vomiting. Women on the anti-obesity pill orlistat who experience severe diarrhoea, for example, are advised to use additional contraceptive precautions as there is a theoretical risk of lack of absorption. The GLP-1 agonist tirzepatide, used for weight loss, can cause oral contraception failure for the first month of use and for one month after every dose increase; women should be advised to use extra precautions, for example, condoms.³

Concomitant administration of COC with some medications may increase levels of the other medication. This may be the case with theophylline, and levels should be monitored. Tacrolimus levels may also be increased, and effect should be monitored.

Durchfall und Erbrechen

• Vomiting within two hours of taking the pill, or very severe diarrhoea, can affect the absorption of the pill.

• The advice for women who experience vomiting or diarrhoea for more than 24 hours is to follow the same advice as if they had missed pills.

Operation

For any woman on COC about to undergo a major elective operation, the risk of thromboembolism needs to be balanced with the risk of unwanted pregnancy. Usually COC would be discontinued four weeks before elective major surgery and restarted on day one of the next period, occurring at least two weeks after mobilisation.⁴ Progestogen-only contraception can be offered as an alternative during this time.

Women requiring emergency surgery should receive subcutaneous heparin and compression stockings, arranged by the surgical team rather than by the GP.

This does not apply to women having minor surgery where there are short periods of anaesthesia, such as tooth extractions or laparoscopic sterilisation.

Amenorrhoe

• There can be Amenorrhoe following cessation of using COC. This is due to the pill's withdrawal bleeds masking an underlying problem, not a direct effect of having used COC.

• Any amenorrhoea lasting more than six months after stopping the pill should be investigated as for secondary amenorrhoea.

Mature women

This is detailed in the separate Verhütung von 40 bis zur Menopause Artikel.

Menorrhagia and dysmenorrhoea^{56 7}

• In women with heavy and/or painful menses COC has been shown to be beneficial. There is evidence for its efficacy in reducing Menorrhagie und dysmenorrhoea. There is no evidence for benefit of one type of COC pill being better than any other.

• The COC can also make the cycle more manageable by running packs together, and in 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 and the FSRH recommends that tailored pill taking is discussed with all women starting COC.

Polyzystisches Ovarialsyndrom (PCOS)⁸

• Women who have PCOS are often oligo-amenorrhoeic.

• Endometrial cystic hyperplasia is associated with prolonged periods of anovulation, as found in PCOS.

• There is an association between PCOS and endometrial hyperplasia and carcinoma. Women should be offered protective therapy from prolonged exposure to relatively unopposed oestrogen. COC does this effectively, as well as providing contraception. However, cardiovascular risks should be taken into account, as women with PCOS are also at risk of the metabolic syndrome, and may be more likely to be overweight; as always, the UKMEC should be used to assess risk.⁹

• Some brands of COC (particularly those containing cyproterone) may be superior to metformin for controlling hormonal effects of PCOS (for example, hirsutism), but evidence reviewed is generally low in quality.¹⁰

Akne¹¹

• Randomised controlled trials have shown significant improvements in acne vulgaris whilst using COC.

• This evidence is specific for preparations containing the progestogens levonorgestrel and norethisterone. There is no consistent evidence to support the use of any particular pill as being more effective than another 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 three months of use. Dianette carries a 50-80% greater risk of venous thromboembolism (VTE) than COC pills containing levonorgestrel, but no higher than those containing gestodene, desogestrel, or drospirenone with 30-35 micrograms of ethinylestradiol.¹²⁷

Reducing the risk of cancer

• The pill has been shown to reduce the risk of ovarian, Endometrium, und colorectal cancer, and lymphatic and haematopoietic cancer.¹³

• The risk reduction is most significant for ovarian cancer. For every five years of use, there is a 20% reduction in the risk of ovarian cancer, and after 10 years of use a woman's risk is half that of a woman who has never taken the pill. This benefit persists for 30 years after stopping COC. ⁷¹⁴

• There is however currently insufficient evidence for the use of COC for the primary prevention of ovarian cancer. Modelling suggests that BRCA mutation carriers should consider using the oral contraceptive pill for chemoprevention, but this is not common practice clinically.¹⁵

• An increased risk of breast cancer seen in current and recent users seems to be lost within approximately five years of stopping oral contraception, with no evidence of increased risk in 'ever' users with time. The risk is small, with a relative risk of 1.19.¹³ For BRCA1 and BRCA2 mutation carriers, the association between COC pill use and breast cancer risk is still unclear, so indications other than contraception should be avoided and non-hormonal contraceptive methods should be discussed. COC is UKMEC 3 (risks generally outweigh benefits) for women with a BRCA mutation. ⁹¹⁶