BNF for Children 2011-2012

396 7.3 Contraceptives BNFC 2011–20127 Obstetrics, gynaecology, and urinary-tract disorders7.3 Contraceptives7.3.1 Combined hormonal contraceptives7.3.2 Progestogen-only contraceptives7.3.3 Spermicidal contraceptives7.3.4 Contraceptive devices7.3.5 Emergency contraceptionThe Fraser Guidelines 1 should be followed when prescribingcontraception for women under 16 years. TheUK Medical Eligibility Criteria for Contraceptive Use(available at www.fsrh.org) is published by the Faculty ofSexual and Reproductive Healthcare; it categorises therisks of using contraceptive methods with pre-existingmedical conditions.Hormonal contraception is the most effective methodof fertility control, but can have major and minor sideeffects,especially for certain groups of women. Hormonalcontraception should only be used by adolescentsafter menarche.Intra-uterine devices are a highly effective method ofcontraception but may produce undesirable local sideeffects.They may be used in women of all ages irrespectiveof parity but are less appropriate for those withan increased risk of pelvic inflammatory disease.Barrier methods alone (condoms, diaphragms, andcaps) are less effective but can be reliable for wellmotivatedcouples if used in conjunction with a spermicide.Occasionally sensitivity reactions occur. Afemale condom (Femidom c ) is also available; it isprelubricated but does not contain a spermicide.7.3.1 Combined hormonalcontraceptivesOral contraceptives containing an oestrogen and aprogestogen (‘combined oral contraceptives’) are effectivepreparations for general use. Advantages of combinedoral contraceptives include:. reliable and reversible;. reduced dysmenorrhoea and menorrhagia;. reduced incidence of premenstrual tension;. reduced risk of symptomatic fibroids and functionalovarian cysts;. less benign breast disease;. reduced risk of ovarian and endometrial cancer;. reduced risk of pelvic inflammatory disease.Combined oral contraceptives containing a fixedamount of an oestrogen and a progestogen in eachactive tablet are termed ‘monophasic’; those with varyingamounts of the two hormones are termed ‘phasic’. Atransdermal patch and a vaginal ring, both containing anoestrogen with a progestogen, are also available.1. See Department of Health Guidance (July 2004): Bestpractice guidance for doctors and other health professionalson the provision of advice and treatment to youngpeople under 16 on contraception, sexual and reproductivehealth. Available at www.dh.gov.ukChoice The majority of combined oral contraceptivescontain ethinylestradiol as the oestrogen component;mestranol and estradiol valerate are also used. Theethinylestradiol content of combined oral contraceptivesranges from 20 to 40 micrograms. Generally apreparation with the lowest oestrogen and progestogencontent which gives good cycle control and minimalside-effects in the individual woman is chosen.. Low strength preparations (containing ethinylestradiol20 micrograms) are particularly appropriate forwomen with risk factors for circulatory disease,provided a combined oral contraceptive is otherwisesuitable.. Standard strength preparations (containing ethinylestradiol30 or 35 micrograms or in 30–40 microgramphased preparations) are appropriate forstandard use—but see Risk of Venous Thromboembolismbelow. Phased preparations are generallyreserved for women who either do not have withdrawalbleeding or who have breakthrough bleedingwith monophasic products.The progestogens desogestrel, drospirenone, and gestodene(in combination with ethinylestradiol) may beconsidered for women who have side-effects (such asacne, headache, depression, weight gain, breast symptoms,and breakthrough bleeding) with other progestogens.However, women should be advised thatdesogestrel and gestodene have also been associatedwith an increased risk of venous thromboembolism.Drospirenone, a derivative of spironolactone, has antiandrogenicand anti-mineralocorticoid activity; it shouldbe used with care if an increased plasma-potassiumconcentration might be hazardous.The progestogen norelgestromin is combined with ethinylestradiolin a transdermal patch (Evra c ).The vaginal contraceptive ring contains the progestogenetonogestrel combined with ethinylestradiol(NuvaRing c ).Risk of venous thromboembolism There is anincreased risk of venous thromboembolic disease (particularlyduring the first year) in users of oral contraceptives,but this risk is considerably smaller than thatassociated with pregnancy (about 60 cases of venousthromboembolic disease per 100 000 pregnancies). Inall cases the risk of venous thromboembolism increaseswith age and in the presence of other risk factors forvenous thromboembolism, such as obesity.The incidence of venous thromboembolism in healthy,non-pregnant women who are not taking an oral contraceptiveis about 5–10 cases per 100 000 women peryear. For those using combined oral contraceptivescontaining second-generation progestogens, such aslevonorgestrel, this incidence is about 15 per 100 000women per year of use. The risk of venous thromboembolismwith transdermal patches may be slightlyincreased compared with combined oral contraceptivesthat contain levonorgestrel. Some studies have reporteda greater risk of venous thromboembolism in womenusing combined oral contraceptives containing thethird-generation progestogens desogestrel and gestodene;the incidence in these women is about 25 per100 000 women per year of use. The absolute risk ofvenous thromboembolism in women using combinedoral contraceptives containing these third-generation