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Injectable Contraceptives - PowerPoint


 Injectable contraceptives
contain hormonal drugs that
 provide women with safe,
    highly effective, and
  reversible contraceptive
      Two types of injectable
        contraceptives :
(1) Progestogen-only formulations
  that contain a progestogen hormone
  and are effective for 2 or 3 months;
(2) Combined formulations that
  contain both a progestogen and an
  estrogen and are effective for 1
    Progestogen -only formulations
•    Consist of DMPA (depot med-
     roxyprogesterone acetate) and NET-EN
     (norethisterone enanthate).
•    DMPA is the injectable formulation
     most widely used worldwide.
•    DMPA is injected every 3 months.
•    NET-EN is injected every 2 months.
Combined formulations
– The most extensively studied
  formulations are known by their
  brand names, Mesigyna;
– Monthly injectable.
– Mesigyna contains the same
  progestogen as NET-EN.&
  contains an added estrogen.
Combined formulations
  Administered by a deep
intramuscular injection into
   the muscle of the arm or
  buttock and are effective
 immediately, provided they
 are taken at specified times
All injectable contraceptives are
     slowly absorbed into the
 bloodstream from the injection
 site, with the body maintaining
 a sufficient level of hormone to
  provide contraception for 1 to
   3 months, depending on the
       type of injectable used
  Name             Active                Duration of   Common
                 ingredients               effect    trade names

    DMPA               150 mg
                medroxyprogesterone       90 days   Depo-Provera,
    only)       acetate in an aqueous               Depo-Clinovir,


 NET-EN              200 mg               60 days   Noristerat,
(progestogen      norethisterone                    Norigest,
                    enanthate                       Doryxas, and
                in an oily preparation
 Mesigyna             50 mg               30 days    Mesigyna,
(combined)      enanthate     and                    Norigynon
                  5 mg estradiol
         Mode of Action
• The immediate action of progestagen-only
  injectables (POIs) is to thicken cervical
  mucus, which then presents an obstacle to
  sperm penetration.
• Also, ovulation is impaired.
• There are additional changes in the
  endometrium that make it unfavourable to
  implantation; however, the first two effects
  make fertilisation highly unlikely.
The reported failure
rates of POIs are low,
 and come within the
   narrow range of
   0.1% to 0.6%.
         Beneficial Effects
          • Prevention of pregnancy
• A single injection of a POI can provide
  highly effective protection against
  pregnancy for two or more months,
  depending on the formulation.
• Delivery is simple, independent of coitus,
  and ensures periodic contact with medical
  or other trained health personnel.
• This is a suitable method for women in
  whom oestrogens present health risks –
  eg, those with a history of thromboembolic
  disorders - and those who have had side
  effects with the use of oestrogens.
 Non-contraceptive health benefits

           Clear benefits
• Sickle cell disease: In a two-year
  trial, women with sickle cell disease
  using DMPA had significantly fewer
  crises than women given a placebo.
• Anaemia: POIs can increase
  haemoglobin concentration, mainly
  by reducing menstrual blood loss.
  Non-contraceptive health benefits
             Possible benefits
1. Endometrial cancer:
• In a World Health Organization (WHO) study, women
  who had ever used DMPA had one-fifth the risk of
  developing endometrial malignancy observed in
  women who had not used DMPA.
• The results, although not statistically significant,
  support the hypothesis that use of DMPA might
  protect against this form of cancer.
2. Other:
• The use of POIs possibly protects against pelvic
  inflammatory disease (PID), seizures in women with
  epilepsy, uterine myoma, and endometriosis.

   Menstrual irregularities
• DMPA and NET-EN are associated
  with disruptions of the menstrual
  cycle including amenorrhoea,
  prolonged menses, spotting between
  periods, and heavy bleeding.
• Less than one-third of women
  receiving DMPA report having normal
  menstrual cycles during the first year
  of use.
   Menstrual irregularities
• Amenorrhoea is the most common
  side-effect and its occurrence
  increases with duration of use from
  about 50 % of DMPA users by the
  end of one year to 80% by the end
  of 5 years.
• Women using NET-EN are less likely
  to experience amenorrhoea.
   Menstrual irregularities
• Heavy bleeding is uncommon (occurs in
  1-2% of users), and prolonged bleeding is
  seldom heavy enough to be a threat to
• Any woman who reports prolonged or
  heavy bleeding may need to be
  evaluated for anemia.
• Anaemia treatments include nutritional
  advice & an appropriate dosage of oral
  iron tablets.
     Menstrual irregularities
• Treatments for heavy bleeding include
  non-aspirin anti-inflammatory drugs such
  as ibuprofen, short-term use of combined
  oral contraceptives or estrogen, or early
  administration of the next injection (not
  sooner than 4 weeks after the previous
• If these measures are not effective or the
  woman’s health is threatened, POIs
  should be discontinued.
    Other Side-Effects
• After menstrual changes, weight gain,
  headache, and dizziness are the next most
  common side-effects reported.
• Most users of POIs put on weight and this is a
  common reason for discontinuation.
• The average DMPA user gains 1.5–2.0 kg in
  the first year and some users continue to gain
  weight thereafter at about the same rate.
• In clinical trials, between 3% and 19% of users
  of injectables have reported headache or
  dizziness. Few women discontinue for these
  Possible Carcinogenicity
• Clinical studies have found no association
  between DMPA use and cervical, ovarian, or
  liver cancers,
• And have confirmed a substantial protective
  effect against endometrial cancer.
• Studies have found no overall increase in
  risk of breast cancer.
• Although some studies have indicated a small
  increased risk of breast cancer in some younger
  women following initial exposure, the studies
  show no trend toward increased risk among
  more long-term users.
             Bone density
• Findings to date suggest a relatively small
  and reversible effect, with no serious health
  risk for women of any age.
• At present, medical experts recommend no
  restriction on use of injectables by
  adolescents over age 16.
• Changes in calcium uptake by bone and
  decreases in urinary calcium excretion have
  been documented and there is a suggestion
  of a relation between long term use of
  DMPA and low bone mass.
Effect on fetal exposure
• There are no known adverse effects of fetal
  exposure to injectables.
• Studies of teenage children who were exposed
  to DMPA in utero show no significant
  differences in health, growth, or sexual
  development compared to other children.
• Progestogen-only injectables can be used by
  breastfeeding women at 6 weeks postpartum
  without adverse effects on nursing infants.
    Effect on Metabolism
• The only metabolic effect of undoubted clinical
  importance is weight gain.
• - Minor alterations of lipid metabolism,
  fluid/nitrogen balance, glucose tolerance,
  steroid metabolism, and immune function
  have been recorded but seem to be of no
  clinical significance.
• - Fewer data have been published on the
  metabolic effects of NET-EN, but its effect on
  most biochemical functions appears to be similar
  to that of DMPA.
   Cardiovascular Effect
• Data are insufficient to indicate whether there
  is any relation between DMPA use and
  cardiovascular complications.
• Results of a WHO study suggest that there is
  little or no increased risk of cardiovascular
  disease associated with the use of
  progestagen-only injectables, although further
  investigation is needed into a possible
  increased risk of stroke among women with
  high blood pressure.
• Fertility is not impaired after discontinuation of
  DMPA or NET-EN although its return is delayed.
• The average time between the last DMPA injection
  and conception is about nine months, including the
  three months during which the injection is effective.
• More than 80% of women become pregnant within
  one year of discontinuing DMPA and 90% within
  two years.
• The few data on NET-EN suggest that fertility
  returns more quickly with this agent.
World Health Organization (WHO) developed eligibility
 criteria for the use of various contraceptive methods.
• Category 1: A condition for which there is no
  restriction for the use of the contraceptive method.
• Category 2: A condition where the advantages of
  using the method generally outweigh the theoretical
  or proven risks.
• Category 3: A condition where the theoretical or
  proven risks usually outweigh the advantages of
  using the method.
• Category 4: A condition which represents an
  unacceptable health risk if the contraceptive method
  is used.
       (category 4):
  POIs should not be used in
          the presence of:
1. Confirmed or suspected
2. Malignant disease of the
     Conditions requiring careful
     consideration (category 3):
   POIs should generally not be used in the
                 presence of:
1. Diabetes with vascular disease or of >20 years’
2. Cerebrovascular or coronary artery disease
3. Acute liver disease
4. 4.benign or malignant liver tumours
5. Severe hypertension/ (BP>180/110 mm Hg)
6. Hypertension with vascular disease
7. Focal migraine .
8. severe cirrhosis
    Other Conditions (category 2)

- Women with mild to moderate hypertension,
  diabetes (without vascular complications),
  hyperlipidaemias, or mild (compensated)
  cirrhosis can generally use POIs.
- Careful screening and appropriate
  monitoring will allow the benefits of using
  POIs to outweigh any potential risks.
       Mode of Action
• Combined injectable contraceptives
  (CICs) exert their contraceptive effect
  mainly by suppressing ovulation.
• In addition, thickening of the cervical
  mucus (mainly due to the progestagen)
  presents an obstacle to sperm penetration.
• The receptivity of endometrium to the
  blastocyst is also reduced.
• In clinical trials, Cyclofem
  /Cycloprovera and
  Mesigyna/Norigynon have both
  proved highly effective
• With 12-month failure rates of 0.2%
  or less for Cyclofem and 0.4% for
     Beneficial Effects
• A single injection of a CIC can
  provide highly effective protection
  against pregnancy for one month.
• Delivery is simple and independent
  of coitus, and in general CICs are
  associated with better cycle control
  than POIs.
• In clinical trials, side-effects of CICs
  included irregular bleeding,
  amenorrhoea, heavy bleeding,
  prolonged bleeding, headaches,
  dizziness, and body weight
• However, these side-effects are much
  less common than with the use of
  Return of Fertility
• The return of fertility following CIC
  use is noticeably shorter than that
  observed for POIs.
• More than 50% of women become
  pregnant within six months of
  discontinuing CICs and 80% within
  one year.
     Eligibility Criteria
Until sufficient clinical data become
 available, the eligibility criteria for
  the use of combined injectable
    contraceptives are based on
      data from combined oral
   Injectable contraceptives have
       important advantages in
adolescents; however, in those under
 16 years of age there are concerns
  regarding the hypo-oestrogenic
effects of POIs, which may affect the
   post-menarche increase of bone
           mineral density.
     Women Over 35
• POIs and CICs can be used by most
  healthy women over 35.
• Any increase in risk of
  cardiovascular disease will be
  minimal for these women if they do
  not smoke and have no other risk
  factors, such as hypertension or
  (in Breast feeding Women)
• If a woman wishes to start injectable
  contraception during breastfeeding a POI
  should be recommended.
• DMPA and NET-EN have no apparent
  negative influence on milk production or the
  duration of lactation; and infants whose
  mothers have received DMPA while
  breastfeeding seem to develop normally, both
  physically and mentally.
   (in Breast feeding Women)
• The question of possible
  consequences of the transfer of
  the injectable steroid to the
  breastfed infant has yet to be
• The amounts of steroid transmitted in
  the milk and absorbed by the infant
  are known to be small.
    (in Breast feeding Women)
• Short-term follow-up studies of children
  breastfed by mothers using progestagen-
  only contraceptives have given reassuring
  results, but longer-term studies are yet to
  be evaluated.
• It is recommended that breastfeeding
  women should not start POIs before the
  sixth week postpartum.
    (in Breastfeeding Women)
• There are no data on the effects of CIC
  formulations on the quantity and
  quality of breast milk or the duration of
• Until such data become available, CICs
  should generally be withheld until six
  months after delivery or until the infant
  is weaned, whichever is the earlier
 (in Non-Breast feeding Women)
• To avoid increasing the risk of
  thromboembolic complications in the
  postpartum period, CICs should not be
  used during the first three weeks after
• After 21 days, blood coagulation and
  fibrinolysis are essentially back to normal.
• POIs can be started at any time after
     Drug Interaction
• Drugs that induce liver enzymes may
  lessen the efficacy of hormonal
• Such drugs which are commonly used in
  long-term treatments include the
  antibiotics rifampicin and griseofulvin
  and the anticonvulsants phenytoin,
  carbamazepine, and barbiturates.
Prevention of STD/HIV Transmission
• Strict aseptic techniques should be
  maintained when giving the injections to avoid
  the risk of transmitting any infection including
• Injectable contraceptives do not protect
  against STD/HIV infection.
• Therefore, when there is a risk of sexual
  transmission of infection, condoms should
  always be used in addition to injectable
      Elective Surgery
• It is advisable to stop using CICs about four
  weeks before elective surgery that will involve
  prolonged immobilisation, and to restart them
  two weeks after the woman has returned to
• Alternative effective contraception, including
  POIs, should be advised during this time.
• In emergency procedures, the surgeon may
  consider prophylactic anticoagulant
  Sickle Cell Disease
• Either POIs or CICs can be used
  by women with sickle cell disease
  but POIs are a more suitable
• In addition to their contraceptive
  effect, there is some evidence of
  benefit on the disease itself.
• Clients considering the use of injectable
  contraception should be clearly informed about
  the advantages and disadvantages of the
  agents, their side-effects, their cost, and the
  alternative contraceptive options.
• Where once-a-month injectables are available,
  clients should be told about the differences
  between these injectables and POIs.
• Women who desire a rapid return to fertility
  on discontinuation of their contraceptive should
  be advised to use CICs where available or
  another method.
some misconceptions
  about injectables
 Do injectable contraceptives
       cause infertility ?

 Although a woman's return to fertility
  can be delayed after injectables are
     discontinued, injectables do not
             damage fertility.
  Do injectable contraceptives
    increase cancer risks ?

Overall increase in cancer risk has
  not been demonstrated in long-
    term, multicountry studies of
          injectable users.
 When amenorrhea occurs, does
 menstrual blood build up in the
   body, leading to disease ?

   Amenorrhea is not a health
It does not cause blood to build
         up in the body.
  Can injectable contraceptives
         transmit disease ?
• No.
• Injectable contraceptives are sterile
  preparations that are free from
  disease- causing agents.
• Contaminated needles and syringes
  used to administer injectables can
  transmit disease, however.
special injection
• Injectable contraceptives are
  administered using deep
  intramuscular injection
• The injection site should not
  be massaged afterwards,
  since this may accelerate
  absorption of the drug.
• Because DMPA is an aqueous
  suspension, a DMPA vial must be
  shaken vigorously before it is
  loaded into the syringe, to
  resuspend any active ingredient in
  the bottom of the vial.
• The syringe should then be checked
  to ensure that it contains the correct
• NET-EN is an oil-based solution
  that needs special care to ensure
  that all the solution is both loaded
  and injected without leakage.
• Warming the vial to body
  temperature makes it easier to
  draw into the syringe.
• Since Mesigyna is an oil-based
  solution similar to NET-EN, the
  same attention to leakage applies.
When can the initial
injection be given ?
  Progestogen -Only Injectables

• DMPA and NET-EN :
• During the first 7 days of the menstrual
• Injectables will be immediately effective.
• Immediately after abortion.
• At other times in a menstrual cycle as long
  as the possibility of pregnancy is ruled out.
• At 6 weeks postpartum.
     Combined Injectables
• During the first 5 days of the menstrual
• Injectables will be immediately
• Immediately after abortion.
• At other times in a menstrual cycle as
  long as the possibility of pregnancy is
  ruled out.
• At 6 months postpartum.
  Margin for
the follow-up
•Progestogen-Only Injectables
      DMPA and NET-EN:
up to 2 weeks (14 days) early or

   • Combined Injectables
   Up to 3 days early or late
       Breast feeding
• Progestogen-Only Injectables
Suitable for women who are breastfeeding at
             6 weeks postpartum.

• Combined Injectables
 Not suitable for women who are fully breast
      feeding until 6 months postpartum.

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