Injectables ppsx

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Background

In the UK, the only injectable currently licensed for long-term use

is depot medroxyprogesterone acetate (DMPA) – Depo-Provera

– and it has been given additional approval as a first-line contra￾ceptive. It has been repeatedly endorsed by the expert commit￾tees of prestigious bodies, such as the International Planned

Parenthood Federation and WHO. DMPA is even safer than

COCs, in spite of the adverse publicity it often receives.

Anxiety about this method was generated by animal research of

very doubtful relevance to humans. WHO data indicate that DMPA￾users have a reduced risk of cancer, with no overall increased risk

of cancers of the breast, ovary or cervix – and a fivefold reduction

in the risk of carcinoma of the endometrium (relative risk 0.2).

There is still the possibility of a weak cofactor effect on breast

cancer in young women similar to that with COCs. However, this

is unproven, and the apparent association may be due to surveil￾lance bias in early years of use by the younger women.

Administration

There are actually two injectable agents available: DMPA

150 mg every 12 weeks, and Noristerat (norethisterone

enanthate; Schering Health Care) 200 mg every 8 weeks, both

given by deep intramuscular injection in the first 5 days of the

menstrual cycle. Injections may also be given beyond day 5,

with 7 days added precautions if it is near certain that a concep￾tion risk has not been taken. The injection sites, in the UK

Injectables

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