Injectable Contraceptives

Injectable Contraceptives
Mechanisms of Action
Progestin-only
DMPA
Hormones
Duration of effect
Combined
Progestin Progestin
3
months
Suppress hormones
responsible
for ovulation
NET-EN
Progestin
+ estrogen
1
month
2
months
Thicken
cervical
mucus
Progestin-only Injectables: DMPA
• Depot-medroxyprogesterone acetate
• 150 mg every 3 months
• Most widely known as Depo-Provera
World Bank
DMPA: Disadvantages
• Causes side effects, particularly menstrual changes
• Action cannot be stopped immediately
• Causes delay in return to fertility
• Provides no protection against STDs, including HIV
DMPA: Advantages
• Safe and highly effective
• Easy to use
• Long-acting
• Reversible
• Can be discontinued without provider’s help
• Can be provided outside of clinics
• Requires no action at time of intercourse
• Use can be kept private
• Has no effect on lactation
• Has noncontraceptive benefits
DMPA: Menstrual Changes
100
Percent
80
of users
(approx.)
60
Amenorrhea
40
20
Prolonged or irregular bleeding
0
6
DMPA: Safety Concerns
• Relationship to cancer
- no overall increased risk of breast cancer
- no increased risk of invasive cervical cancer
- protection from endometrial cancer
- no link with ovarian and liver cancers
• Fetal exposure
- no harmful effect on fetus
• Exposure of breastfeeding infants
- no effect on lactation, milk production or
health of infant
• Effect on bone density
- concern that young users may develop osteoporosis
- long-term studies are needed
12
Months of use
18
24
DMPA: Return to Fertility
Percent of women having conceived
100
80
60
40
Oral Contraceptives (0=last pill taken)
20
DMPA (0=15 weeks after last injection)
0
4
8
12
16
20
Months after stopping contraceptive
Source: Tieng, 1982.
24
Progestin-only Injectables: NET-EN
• Norethisterone enanthate
• 200 mg every 2 months
• Most widely known as Noristerat or Norigest
NET-EN: Differences from DMPA
NET-EN: Similarities to DMPA
• Effectiveness
• Safety
• Mechanisms of action
• Advantages and disadvantages
• Eligibility criteria
DMPA
NET-EN
Duration of effectiveness
3 months
2 months
Menstrual changes
More
Less
Cost
Lower
Higher
Combined Injectables
Combined Injectables: Disadvantages
• Contain progestin and estrogen
• Administered monthly
• Causes side effects, particularly menstrual changes
• Action cannot be stopped immediately
• Requires monthly injections
• Provides no protection against STDs, including HIV
• Most widely known products
are Cyclofem and
Mesigyna
Combined Injectables: Menstrual Changes
Combined Injectables: Advantages
• Safe and highly effective
• Easy to use
• Reversible
• Can be discontinued without provider’s help
• Can be provided outside of clinics
• Requires no action at time of intercourse
• Use can be kept private
• May have noncontraceptive benefits
Providing Injectables
PA
blee
ding
cha
60
Percent
of users
40
20
nge
s
Cyclofem
bleeding changes
DMP
A am
enor
rhea
Cyclofem amenorrhea
0
3
6
Months of use
9
• Can be delivered at pharmacies and in homes
• Can be provided by trained nurses, pharmacists
and community-based workers
• Reminder mechanism needed to ensure return visit
• Programs providing injectables need:
- dependable supply
of injectables, needles
and syringes
- adequate storage
facilities
- mechanism for timely
distribution
B. Goldberg
© Family Health International, 1999
DM
Programmatic Issues
Counseling
• Menstrual changes are most common
reason for discontinuation
• Women receiving appropriate
counseling more likely to continue
injectables use
• Factors for client to consider include:
- other available contraceptive
options
- advantages and disadvantages
- side effects including menstrual
changes
- timing of return to fertility
- need for regular, timely injections
80
12