Traditional Progestin Only Pills

Traditional progestin-only pills are low-dose oral contraceptives taken every day without a pill-free interval. Each tablet contains levonorgestrel 30 microgram. Norethisterone 350 microgram and norgestrel 75 microgram tablets are other traditional formulations. They contain no oestrogen and do not reduce milk supply, but the cervical mucus effect fades within about a day, so timing is strict.

Mechanism. Thickened cervical mucus is the main effect. Ovulation is suppressed in some cycles only, and the endometrium thins. About 48 hours of use is needed to establish the mucus effect.

Pharmacokinetics. Levonorgestrel is well absorbed, peaks within 1 to 2 hours and has an elimination half-life of about one day.

Effectiveness. Typical use: 9 pregnancies in 100 women in the first year. Perfect use: 0.3 in 100. During exclusive breastfeeding with correct use the rate is about 0.5 in 100. Effectiveness is lower in women who are not breastfeeding.

Onset and return to fertility. Protection starts after 48 hours unless the first tablet is taken on days 1 to 5 of menses. Fertility returns at once after stopping.

Ideal candidates. Breastfeeding women from 4 weeks postpartum, and patients with a contraindication to oestrogen who can take a tablet at the same time each day. Patients with chaotic routines or frequent missed doses are poor candidates.

Assessment. Menstrual, breastfeeding and medicine history, and blood pressure. Pelvic examination, breast examination and routine laboratory tests are not needed. Exclude pregnancy by the usual criteria: baby under 6 months, fully breastfeeding and amenorrhoeic; delivery within 21 days; no sex since the last normal period; within 5 days of menses; within 5 days of abortion; consistent use of a reliable method; or a negative test with no unprotected sex for 3 weeks.

Eligibility categories.

• Category 1: any age or parity; breastfeeding from 4 weeks; smoking; obesity; controlled hypertension or blood pressure 140 to 159 over 90 to 99 mm Hg; family history of thrombosis; migraine without aura; HIV; tuberculosis and epilepsy (subject to the interacting medicines listed under category 3); mild compensated cirrhosis; viral hepatitis; sickle cell disease; pelvic inflammatory disease; sexually transmitted infections.
• Category 2: breastfeeding under 4 weeks; past ectopic pregnancy; antiretroviral therapy with efavirenz, nevirapine or ritonavir-boosted regimens; unexplained or heavy bleeding (evaluate first); diabetes with vascular disease or blood pressure of 160/100 mm Hg or more; past deep vein thrombosis; ischaemic heart disease or stroke; gallbladder disease; undiagnosed breast lump; lupus without positive antiphospholipid antibodies.
• Category 3: phenytoin, carbamazepine, barbiturates, primidone, topiramate, oxcarbazepine; rifampicin or rifabutin; acute deep vein thrombosis or pulmonary embolism; severe decompensated cirrhosis or liver tumour; lupus with positive or unknown antiphospholipid antibodies; past breast cancer.
• Category 4: current breast cancer.

Interactions. Rifampicin, rifabutin, enzyme-inducing antiseizure medicines, efavirenz, ritonavir-boosted regimens, griseofulvin and St John’s wort reduce effectiveness. Choose DMPA or an intrauterine device for long-term inducer use. Broad-spectrum antibiotics other than rifamycins and most antifungals do not reduce effectiveness.

Counselling. Consent, confidentiality and absence of coercion apply. Stress the same-time-daily rule, unpredictable bleeding and condom use for infection protection. Adolescents under 18 years give assent and consent follows the law.

Regimen.

• Levonorgestrel 30 microgram tablet, orally, one tablet daily at the same time, continuously, starting the next pack the day after the last tablet.
• Protection begins 48 hours after the first tablet, or at once if started on days 1 to 5 of menses.
• A tablet is late when taken 3 hours or more after the usual time.
• Backup: condoms or abstinence for 2 days after a late or missed tablet, or after a later start.
• Switching from a hormonal method used correctly needs no overlap.
• No dose change for body weight. Avoid in category 3 and 4 conditions.

Start timing.

Late or missed tablets.

• Take the missed tablet at once, then continue one tablet daily. Two tablets may be taken on the same day.
• If she has regular menses, use backup for 2 days.
• If she had sex in the last 5 days, consider emergency contraception.
• Vomiting within 2 hours of a tablet: take another tablet. Severe vomiting or diarrhoea over 2 days: count each day as missed and use backup for 2 days after recovery.
• Community providers refer anyone who has missed 3 or more tablets.

Supply and follow up. Community providers start and resupply category 1 users and give up to 3 cycles at a time to category 2 users. Review for problems and at least yearly. Unused tablets are returned and disposed of safely.

Special groups.

• Adolescents: no age restriction; assent under 18 years, consent in line with the law.
• HIV: add condoms with efavirenz, nevirapine or ritonavir-boosted regimens.
• Tuberculosis on rifampicin or rifabutin, or epilepsy on enzyme-inducing medicines: choose DMPA or an intrauterine device.
• Obesity: category 1, no dose change. Liver disease: avoid in severe cirrhosis and liver tumours.
• Perimenopause: pills may be used at any age; stopping can be considered at about 55 years.

Stopping. Fertility returns at once.

Complications. Functional ovarian cysts may form and usually resolve alone. Failure with a pill carries a higher share of ectopic pregnancies.

Red flags. Severe lower abdominal pain needs ectopic pregnancy excluded at once, directly or by immediate referral.

Referral and escalation. Refer abnormal or suspicious bleeding for pelvic examination and cervical screening. Refer pregnancy for antenatal care and stop the pill.