develops during use . As for COCPs , liver-enzyme inducing medications reduce POP efficacy

, and alternative contraception should be advised .

Unlike the oestrogen-containing COCPs , POPs do not offer a range of non-contraceptive benefits , although a small study of the drospirenone 4mg POP in adolescents showed a reduction in dysmenorrhoea over 13 cycles .

POP side effects

Unpredictable bleeding patterns are a common side effect of all progestogen-only methods , including POPs . With traditional POPs , frequent and irregular bleeding are common while amenorrhoea and prolonged bleeding are less common , which may contribute to relatively low continuation rates ( about 40 % at one year ).

The new drospirenone 4mg POP has a four-day hormone-free break which aims to produce predictable scheduled withdrawal bleeding and reduce unscheduled bleeding at other times .

In clinical trials , both scheduled and unscheduled bleeding reduced over time , and by nine months of use 45 % of users experienced no bleeding at all , although another 45 % continued to have some unscheduled bleeding .

Other POP side effects may include acne , headaches , loss of libido , mood changes and weight gain . As for COCPs , a causal relationship is uncertain and evidence-based strategies for their management are lacking . Trialling a different POP or alternative form of contraception may help , while considering other potential causal factors .

SUPPORTING PILL CHOICE ACROSS THE REPRODUCTIVE LIFESPAN

Young people : There is no lower age limit for prescribing COCPs or POPs from the time of menarche . Young women aged under 16 who are assessed as mature minors can consent to contraceptive pill use . It is helpful to explain confidentiality and its limits , and to see the young person alone for some of the consultation . It is also important to assess for risk of harm and follow state- and territory-based mandatory reporting legislation if indicated .

COCPs can help manage acne ,

Table 5 . Progestogen-only contraceptive pills available in Australia

Progestogen dose ( micrograms )

Brand name examples

Levonorgestrel 30 Microlut * 28 hormone pills

Norethisterone 350 Noriday * 28 hormone pills

Drospirenone 4000 Slinda 24 / 4

* PBS-listed at time of writing

dysmenorrhoea and HMB , which are common in adolescence .

While traditional POPs are not generally recommended for adolescents given the narrow missed-pill window , the 24-hour window for the drospirenone 4mg POP may make it a suitable choice .

The cost of some formulations of the COCP or the drospirenone 4mg POP , which are not PBS listed , may limit choices for some young people .

It is important to ensure young pill users are aware , in case of missed pills , of the availability of emergency contraceptive pills without a prescription and the role of simultaneous use of condoms for STI protection .

Overall , the need to remember a daily pill and high background fertility rates may increase the chance of unintended pregnancy in this age group , and information about LARC options should also be provided .

Post-partum and abortion : Fertility may return from 21 days post-partum . All POPs , like other progestogen-only contraceptives ,

Pill pack ( hormone pills / hormone-free pills )

can be initiated immediately after delivery as they don ’ t increase VTE risk . However , taking a traditional POP at exactly the same time each day with a narrow threehour missed pill window may be challenging during this time of disrupted routines , and the drospirenone 4mg POP may be a suitable choice given the longer missed pill window .

Updated UK MEC guidance also advises that COCPs can be generally used from six weeks post-partum in breastfeeding women ( see table 2 ) with no evidence of an adverse effect on either breastfeeding or infant growth .

After first- or second-trimester abortion , COCPs and POPs provide immediate ongoing contraception if started within five days . They can also provide effective bridging contraception prior to a LARC if desired .

Perimenopause : COCPs can be an appropriate contraceptive choice for medically eligible women over the age of 40 , but VTE and arterial vascular risk factors need careful consideration in this group . Additionally ,

Unlike traditional POPs , the drospirenone 4mg POP reliably inhibits ovulation and has a 24-hour missed pill window .

COCPs have benefits for bone density , perimenopausal symptoms and can be used to

manage appropriately investigated HMB .

After age 50 , it is recommended to cease COCPs and switch to a non-hormonal method or a POP , hormonal IUD or progestogen-only implant .

If , after the age of 50 , a woman has had no bleeding while using a POP for 12 months , a blood test for FSH can be undertaken . If this is in the menopausal range , contraception may be stopped after a further 12 months . Alternatively , POPs can be continued until the age of 55 years , after which time contraception is generally no longer required .

Conclusion

Oral contraceptives remain a common choice in Australia and are very effective when taken correctly on a daily basis . COCPs are associated with an increased risk of VTE , but absolute risks are low in medically eligible individuals ( guided by MEC criteria ).

They have additional non-contraceptive benefits for conditions such as acne and HMB . Extended use without a hormone-free interval can be advised to eliminate withdrawal bleeding and potentially optimise non-contraceptive benefits .

POPs are not associated with increased VTE risk , and a new 4mg drospirenone POP offers further choice , with a 24-hour missedpill window rather than the narrow threehour window for traditional POPs .

Contraceptive consultations involve provision of evidence-based information on the safety , efficacy , advantages and disadvantages of all methods of contraception . This enables women to make choices based on their personal preferences and medical suitability .

References on request from kate . kelso @ adg . com . au

Declaration Dr Clare Boerma has participated in advisory committees for Mayne Pharma as part of her role at FPNSW and attended educational events sponsored by Bayer . Professor Bateson has participated in advisory committees and spoken at educational events sponsored by Mayne Pharma , Besins and Bayer as part of her role at FPNSW . Neither have been personally remunerated by any pharmaceutical company .