6.1
Method
It
is also known as minipill. It contains a small dose of progestational
agent and must be taken every day at fixed time in a continous fashion.
6.2 Mechanism of action
With minipill, blood level of progestin is approximately 25% of
that after COC consumption. This low level of progestin in circulation
produces impact only on tissues which are very sensitive to female
sex steroids. With minipill the gonadotrophins are not consistently
suppressed, thus, contraceptive effect is more dependent upon endometrial
and cervical mucus effects.
• the endometrium involutes and becomes
hostile to implantation
• the cervical mucus becomes thick and
impermeable to sperms
• anovulation occurs in 60% of women on
mini pill; the remaining ovulate normally.
• tubal physiology may be affected
6.3 Advantages
•
can be used in nursing mothers 6 weeks after childbirth
• women take one pill every day with no
break, which is easier to understand than taking 21 day combined
pill and then a break of 7 days
• no estrogenic side-effects
• less progestin related side-effects
e.g. acne, and weight-gain
• helps to prevent benign breast disease,
PID, endometrial and ovarian cancer
6.4 Disadvantages
•
strict patient compliance is required
• menstrual irregularity or amenorrhoea
• may cause headache and breast tenderness
6.6 Contraindications
•
breast-feeding mother less than 6 weeks post-partum.
• current deep vein thrombosis/ pulmonary
embolism
• current or past history of breast cancer
• active viral hepatitis and liver tumours
• patient on drugs likely to affect metabolism
of the drug
6.6 Drug Inter-actions
Relatively
lower dose of progestin administered in minipill, warrants against
its use in patients on medications that increase liver metabolism.
These drugs include :
- Rifampicin
- Phenobarbitone
- Phenytoin
- Primidone
- Carbamazepine
- Ethosuximide
- Griseofulvin
- Troglitazone
Intrauterine device (IUD) is a small, flexible
plastic frame to be inserted into the uterine cavity.
6.7 Instructions to the client
• it should
be started on the first day of menses and back-up method must
be used for 7 days.
• the pill should be taken at the same
time every day.
• if the pill is forgotten or gastro-intestinal
illness impairs absorption, the minipill should be resumed as
soon as possible and a back-up method should be used immediately
and until the pill has been resumed for at least 2 days.
• if more than 3 hours late in pill taking,
a back-up method should be used for 48 hours.
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