14 Contraceptives
This is a general term to describe an agent used to prevent conception.
As part of their sphere of practice, midwives have a duty to offer family planning advice (Nursing and Midwifery Council (NMC), 2004; NICE, 2006; Article 42 of the European Union Standards for Nursing and Midwifery, 2009).
The student should be aware of:
the availability of contraception (hormonal, intrauterine devices, barrier methods, spermicidal and emergency contraception)
the importance of family planning
the process of contraception with a view to usage of emergency contraception
the appropriateness of the contraceptive prescribed
the importance of counselling – advice on bleeding, missed pills, diarrhoea and vomiting, antibiotic administration, and cessation of oral contraception prior to surgery.
BP
Combined oestrogen–progestogen oral contraceptive (COC)
Proprietary
Marvelon® (Merck Sharp & Dohme Ltd), Yasmin® (Bayer PLC), Femodene® (Bayer PLC), Microgynon 30® ED, (Bayer PLC), Ovranette® (Pfizer Ltd), Loestrin 20® and Loestrin 30® (Galen Ltd), Millinette® 20/75 (Consilient Health Ltd)
Group
Contraceptive – hormonal
Uses/indications
Contraception, menstrual symptoms
Type of drug
POM
Presentation
Tablets in packs for 1 month, with days numbered
Dosage
Usually 1 tablet/day, but refer to pack for instructions
Postpartum (not breastfeeding) – commence at 3 weeks’ postpartum – there is an increased risk of DVT if commenced earlier – patient must be fully ambulant, with no puerperal complications, and be counselled for the risk of DVT
Breastfeeding – not recommended until weaning or at least 6 months if unable to obtain other contraception
Miscarriage or abortion – commence on same day if possible
Postpartum (not breastfeeding) – commence at 3 weeks’ postpartum – there is an increased risk of DVT if commenced earlier – patient must be fully ambulant, with no puerperal complications, and be counselled for the risk of DVT
Breastfeeding – not recommended until weaning or at least 6 months if unable to obtain other contraception
Miscarriage or abortion – commence on same day if possible
Route of admin
Oral
Contraindications
Pregnancy, migraine, liver disease including cholestatic jaundice, history of pruritus in pregnancy, breastfeeding, prothrombotic coagulation disorders, previous history or strong familial history of DVT, undiagnosed vaginal bleeding, breast or genital tract carcinoma
CAUTION: arterial disease, smoking, hypertension, obesity, diabetes mellitus with retinopathy and nephropathy, ischaemic heart disease, varicosities, depression, inflammatory bowel disease, Rotor syndrome, Dubin–Johnson syndrome, sickle cell anaemia, history of herpes gestationis, disorders of lipid metabolism
Stop prior to major surgery or surgery to the legs, or with long-term immobilization – do not stop for minor surgery with short anaesthetic duration, e.g. laparoscopy or tooth extraction
CAUTION: arterial disease, smoking, hypertension, obesity, diabetes mellitus with retinopathy and nephropathy, ischaemic heart disease, varicosities, depression, inflammatory bowel disease, Rotor syndrome, Dubin–Johnson syndrome, sickle cell anaemia, history of herpes gestationis, disorders of lipid metabolism
Stop prior to major surgery or surgery to the legs, or with long-term immobilization – do not stop for minor surgery with short anaesthetic duration, e.g. laparoscopy or tooth extraction
Side effects
Nausea, vomiting, headache, breast tenderness, changes in body weight, libido changes, DVT, intracycle bleeding, amenorrhoea, decreased menstrual bleeding, depression, impaired liver function
Interactions
Antibiotics – broad spectrum – reduce effect
Anticoagulants – antagonizes the effect of warfarin
Antidepressants – tricyclics – antagonizes the antidepressant effects but increases the side effects because of the increased plasma concentration of tricyclics
Antidiabetics – antagonism of the hypoglycaemic effect
Antiepileptics – carbamazepine, phenobarbital and phenytoin accelerate metabolism and reduce contraceptive effect
Antihypertensives – antagonize hypotensive effect
Anticoagulants – antagonizes the effect of warfarin
Antidepressants – tricyclics – antagonizes the antidepressant effects but increases the side effects because of the increased plasma concentration of tricyclics
Antidiabetics – antagonism of the hypoglycaemic effect
Antiepileptics – carbamazepine, phenobarbital and phenytoin accelerate metabolism and reduce contraceptive effect
Antihypertensives – antagonize hypotensive effect
Pharmacodynamic properties
The combination of these preparations acts to inhibit ovulation by suppressing the mid-cycle surge of luteinizing hormone, thickening the cervical mucus as a barrier to sperm, and rendering the endometrium unresponsive to implantation
Fetal risk
Evidence suggests no harmful effects to fetus, although there is teratogenicity in animals (US studies have found a small risk of 0.07% of all pregnancies exposed to the oral contraceptive pill)
Breastfeeding
Suppressed lactation; contraindicated until at least 6 months after birth
BP
Progestogen-only pill (POP)
Proprietary
Cerazette® (Merck Sharp & Dohme Ltd), Femulen® (Pharmcia Ltd), Micronor® (Janssen Cilag Ltd), Norgeston® (Bayer PLC), Noriday® (Pfizer Ltd)
Group
Contraceptive – hormonal
Uses/indications
Contraception, alternative to oestrogens – higher failure rate, suitable in smokers, hypertension, valvular heart disease, diabetes mellitus, migraine, predisposition to or history of thrombosis or venous thrombosis
Type of drug
POM
Presentation
Tablets in cyclical packs
Dosage
Usually 1 tablet/day, but refer to pack instructions – must be taken at the same time each day
postpartum – commence after 3 weeks – breakthrough bleeding if earlier – women should also be aware of the increased risk of thromboembolic disorders
postpartum – commence after 3 weeks – breakthrough bleeding if earlier – women should also be aware of the increased risk of thromboembolic disorders
Route of admin
Oral
Contraindications
Pregnancy, undiagnosed vaginal bleeding, severe arterial disease, existing thrombophlebitis or thromboembolic disorders, cerebrovascular disease, porphyria, heart disease including myocardial infarction, malabsorption syndromes, liver disease, sex steroid-dependent cancers, past ectopic pregnancy, functional ovarian cysts, cholestatic jaundice, pruritus of pregnancy, Dubin–Johnson syndrome, Rotor syndrome, history of herpes gestationis, disorders of lipid metabolism
Side effects
Menstrual irregularities, nausea, vomiting, menstrual symptoms, weight change, depression, dizziness, loss of libido, headaches, chloasma
Interactions
Antibiotics – rifamycins – increase metabolism and therefore reduce effect
Anticoagulants – antagonize effect of warfarin
Antidiabetics – antagonize the hypoglycaemic effects
Antiepileptics – reduce contraceptive effect
St John’s wort – can lead to potential loss of contraceptive effect
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Anticoagulants – antagonize effect of warfarin
Antidiabetics – antagonize the hypoglycaemic effects
Antiepileptics – reduce contraceptive effect
St John’s wort – can lead to potential loss of contraceptive effect
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