Progestin Only Contraceptives Flashcards
what are the 4 main forms of POC?
- progestin only pill (POP)
- Depo Medroxyprogesterone acetate injection (DMPA)
- Levonorgestrel-releasing IUS
- Etonogestrel-releasing implant
what does LARC stand for?
long-acting contraceptive
are IUD and IUS the same thing?
no, IUS released medication
in 2018, what % of women in Canada were of childbearing age?
52%
what are the 2 most common forms of birth control in Canada?
condoms and combined oral contraceptives (followed by withdrawal)
imperfect contraceptive adherence is thought to account for __% of unplanned pregnancies
69%
what is the direct cost (dollar amount) for unintended pregnancy in Canada?
$320 million
up to __% of pregnancies are unintended
40%
what forms of contraception can PhC prescribe? What cant they prescribe?
everything except intrauterine contraception and implants
what is the effect of endogenous progesterone on ovulation?
negative feedback on hypothalamus/pituitary gland –> decrease in release of GnRH –> decrease release of FSH & LH –> no primary follicle (no ovulation) –> no follicle induced release of estrogen –> low estrogen –> no estrogen peak –> no LH surge (no ovulation)
aside from effects on follicle formation, how does progesterone contribute to contraception? (2 more ways)
- produces thick hostile cervical mucous
2. changes endometrial lining (may lead to atrophy)
what is the active drug in progestin only pill?
norethindrone 0.35mg
what is the active drug and concentration in the Depo shot?
medroxyprogesterone acetate 150mg
what is the active ingredient in IUS?
levonorgestrel
what is the active ingredient in the implant?
etonogestrel
what is the main MOA of the progestin only pill? The secondary MOA?
primary: hostie cervical mucous and low endometrium
Secondary: decreased ovulation
what is the primary MOA of Depo?
decreased ovulation
what are the 2 main MOAs of an IUS?
making hostile cervical mucous and low endometrium
what is the main MOA of the implant?
decreased ovulation
definition of menses or “period”
part of normal, physiologic hormone cycle: shedding of the uterine lining if implantation does not occur
definition of irregular vaginal bleeding
abnormal or irregular flow of blood from uterus between menses
what are 5 possible causes of irregular vaginal bleeding?
- hormonal imbalances
- pregnancy
- fibroids (noncancerous growths)
- infection
- cancer
what are 2 terms used to describe irregular vaginal bleeding?
BTB and spotting
what is the general definition of BTB?
irregular bleeding requiring the use of pad or tampon
what is the general definition of spotting?
irregular bleeding that is less than BTB and does not require pads/tampons etc.
definition of withdrawal bleeding
bleeding that occurs when using some hormonal methods of contraception are stopped (drop in progesterone), resulting in bleeding
t/f withdrawal bleeding occurs on a regular and predictable basis
t
what is the trigger for withdrawal bleeding?
a drop in exogenous progesterone
what is the trigger for menses?
lack of implantation which leads to regression of corpus lutem and the a decrease in endogenous progesterone
t/f what is expelled during menses and withdrawal bleeding is basically the same, but the reason for start is different
t
will menses occur with the POP?
depends on if ovulation is supressed or not (this is not consistent with POP)
if POP is started on day 1-5 of cycle, when will the menses occur?
the last 7 days of the pack
is there a hormonal free interval with any form of progesterone only contraceptives?
no
is there a withdrawal bleed with progestin only contraceptives?
no, bc there are no HFIs
what % of women have a normal cycle after 12 months of DMPA injections?
11%
will there be a menses on IUS?
ovulation is not suppressed, irregular bleeding for a few months and eventually the endometrium becomes not responsive
will there be a menses with the implant?
ovulation is suppressed, there will be irregular bleeding for a few months and eventually the endometrium will be come unresponsive
what POC has the highest rate of irregular bleeding?
POP
which IUS has higher rate of ammenorrhea? Why?
Mirena bc it has higher concentration of levonorgestrel
ammenorrhea occurs in __% of people on IUS by 1 year
50
what % of people have ammenorrhea by 1 year? 2 years?
1 year: 55%
2 years: 68%
what % of people have ammenorrhea with the implant?
22-30%
what are some common ADRs with POP?
BTB, headaches, breast tenderness, nausea, mood disturbances
what are the danger signs for POP?
abdominal pain (cyst, ectopic pregnancy)
Delayed period after several months (pregnancy)
Repeated, severe headaches
which POP causes a delay in fertility?
DMPA
what POP causes reversible decreased BMD?
DMPA
how long does it take for fertility to come back after stopping DMPA?
6 months
does DMPA cause weight gain?
yes, up to 2.5kg in 1 yr
what are some danger signs with a IUS?
- change in strings
- pain/bleeding in sex
- pregnancy
- exposure or sx of STI
- pelvic pain or sore abdomen
- fever or chills
can the implant cause weight gain? How much>
yes; 1.9kg over 2 years
what POC cause weight gain?
all of them,but especially DMPA and implant
what POC causes reversible BMD loss?
depo shot
what is an absolute c/i for POC use?
breast cancer
what are some common drugs that interact with POC?
anticonvulsants (like phenytoin, carbamazepine), antibiotics (like rifampin), st. John’s wort
what POC can be used in breastfeeding?
all of them
how long do the IUS last?
5 years
how long do the implants last?
3 years
how often is a depo shot needed?
3 months
which POC may result in amenorrhea?
all but the pills
if starting POP within 5 days of menses, how long is backup needed?
no backup needed
if starting POP >5days of cycle, how long is backup needed? Why?
48 hours bc sperm can penetrate the cervical mucous if the interval is >24 hours
POP need to be taken at the same time each day within a ___hour window
3
if it has been more than a 3 hour window of when you’re supposed to take your POP, how long do you need to use backup?
48 hours
if starting a depo shot within the first 5 days of menses, how long do you need backup?
24 hours
if depo is given >5 days of the cycle, how long do you need backup?
7 days
pregnancy must be ruled out if its been ___weeks or more since the last shot
14
what is the dose of levonorgestrel in a Mirena IUS?
52mg that releases 14mcg/day
what is the dose of levonorgestrel in Kyleena IUS?
19.5mg with 9mcg/day
how long is backup needed after inserting IUS (regardless of cycle day started)?
7 days
if an implant is started >5days of cycle, how long is backup needed?
7 days
when should initial monitoring be done with POC?
within first 4 weeks
how often should POC be monitored?
every 12 weeks
