الفهرس 
Combined oral contraceptive pillsOnly 14 pages are availabe for public view
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Abstract
ombined oral contraceptive is one of the most commonly
prescribed birth control methods, used by millions of women in many
countries (Nisenbaum et al., 2014).
Combined oral contraceptive (COC) is a popular and effective
method for contraception. Since the dose of estrogen or the type of
progestin component in COCs are associated with adverse events,
especially venous thromboembolism (Pazol et al., 2018)
There are many different formulations or brands, but the
average pack is designed to be taken over a 28-day period, or cycle.
For the first 21 days of the cycle, users take a daily pill that contains
hormones (estrogen and progestogen). The last 7 days of the cycle are
hormone free days. Some packets only contain 21 pills and users are
then advised to take no pills for the following week. Other packets
contain 7 additional placebo pills, or biologically inactive pills (Evans
and Sutton, 2015).
A woman on the pill will have a withdrawal bleed sometime
during her placebo pill or no pill days, and is still protected from
pregnancy during this time. Then after 28 days depending on which
type a person is using, users start a new pack and a new cycle (Evans
and Sutton, 2015).
Contraceptive efficacy may be impaired by: missing more than
one active pill in a packet, delay in starting the next packet of active
pills (i.e., extending the pill-free, inactive or placebo pill period
beyond 7 days), intestinal malabsorption of active pills due to
vomiting or diarrhea, drug interactions with active pills that decrease
contraceptive estrogen or progestogen levels. (Akintomide et al.,
2018).