INJECTABLE CONTRACEPTIVES

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INJECTABLE CONTRACEPTIVES
Dr.Ashraf Fouda Ob/Gyn. Specialist Dommiatte
General Hospital
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Introduction

• Injectable contraceptives contain hormonal drugs
  that provide women with safe, highly effective,
  and reversible contraceptive protection.

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Two types of injectable contraceptives

• (1) Progestogen-only formulations that contain a
  progestogen hormone and are effective for 2 or 3
  months and,
• (2) Combined formulations that contain both a
  progestogen and an estrogen and are effective for
  1 month

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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.

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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.

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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

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• 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

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PROGESTOGEN ONLY INJECTABLES
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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.

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Efficacy

• The reported failure rates of POIs are low, and
  come within the narrow range of
• 0.1 to 0.6.

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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.

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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.

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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.

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PROGESTOGEN ONLY INJECTABLES

• SIDE EFFECTS

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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.

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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.

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Menstrual irregularities

• Heavy bleeding is uncommon (occurs in 1-2 of
  users), and prolonged bleeding is seldom heavy
  enough to be a threat to health.
• 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.

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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 injection).
• If these measures are not effective or the
  womans health is threatened, POIs should be
  discontinued.

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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 1.52.0 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
  reasons.

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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.

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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.

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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.

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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.

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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.

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RETURN OF FERTILITY

• 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.

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Eligibility Criteria for Use of a Contraceptive
Method
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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.

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Contra-indications (category 4)

• POIs should not be used in the presence of
• Confirmed or suspected pregnancy
• Malignant disease of the breast

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Conditions requiring careful consideration
(category 3)

• POIs should generally not be used in the presence
  of
• Diabetes with vascular disease or of gt20 years
  duration
• Cerebrovascular or coronary artery disease
• Acute liver disease
• 4.benign or malignant liver tumours
• Severe hypertension/ (BPgt180/110 mm Hg)
• Hypertension with vascular disease
• Focal migraine.
• severe cirrhosis

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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.

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COMBINED INJECTABLE CONTRACEPTIVES
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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.

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Efficacy

• In clinical trials, Cyclofem /Cycloprovera and
  Mesigyna/Norigynon have both proved highly
  effective contraceptives
• With 12-month failure rates of 0.2 or less for
  Cyclofem and 0.4 for Mesigyna.

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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.

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Side-Effects

• In clinical trials, side-effects of CICs included
  irregular bleeding, amenorrhoea, heavy bleeding,
  prolonged bleeding, headaches, dizziness, and
  body weight changes.
• However, these side-effects are much less common
  than with the use of POIs.

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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.

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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 contraceptives

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Special Situations
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Adolescents

• 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.

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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 diabetes.

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Postpartum (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.

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Postpartum (in Breast feeding Women)

• The question of possible consequences of the
  transfer of the injectable steroid to the
  breastfed infant has yet to be resolved.
• The amounts of steroid transmitted in the milk
  and absorbed by the infant are known to be small.

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Postpartum (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.

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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 lactation.
• 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

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Postpartum (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 delivery.
• After 21 days, blood coagulation and
  fibrinolysis are essentially back to normal.
• POIs can be started at any time after delivery.

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Drug Interaction

• Drugs that induce liver enzymes may lessen the
  efficacy of hormonal contraceptives.
• Such drugs which are commonly used in long-term
  treatments include the antibiotics rifampicin and
  griseofulvin and the anticonvulsants phenytoin,
  carbamazepine, and barbiturates.

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Prevention of STD/HIV Transmission

• Strict aseptic techniques should be maintained
  when giving the injections to avoid the risk of
  transmitting any infection including HIV.
• 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 contraceptives.

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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 mobility.
• Alternative effective contraception, including
  POIs, should be advised during this time.
• In emergency procedures, the surgeon may
  consider prophylactic anticoagulant measures

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Sickle Cell Disease

• Either POIs or CICs can be used by women with
  sickle cell disease but POIs are a more suitable
  choice.
• In addition to their contraceptive effect, there
  is some evidence of benefit on the disease itself.

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Counselling

• 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.

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some misconceptions about injectables
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Do injectable contraceptives cause infertility ?

• No.
• Although a woman's return to fertility can be
  delayed after injectables are discontinued,
  injectables do not damage fertility.

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Do injectable contraceptives increase cancer
risks ?

• No.
• Overall increase in cancer risk has not been
  demonstrated in long-term, multicountry studies
  of injectable users.

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When amenorrhea occurs, does menstrual blood
build up in the body, leading to disease ?

• No.
• Amenorrhea is not a  health risk.
• It does not cause  blood to build up in the body.

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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.

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special injection techniques
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• Injectable contraceptives are administered using
  deep intramuscular injection techniques.
• The injection site should not be massaged
  afterwards, since this may accelerate absorption
  of the drug.

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• 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 dosage.

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• 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.

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When can the initial injection be given ?
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Progestogen -Only Injectables

• DMPA and NET-EN
• During the first 7 days of the menstrual cycle.
• 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.

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Combined Injectables Mesigyna

• During the first 5 days of the menstrual cycle.
• 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 months postpartum.

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Margin for the follow-up re-injection
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Progestogen-Only Injectables DMPA and NET-ENup
to 2 weeks (14 days) early or late

• Combined Injectables Mesigyna
• Up to 3 days early or late

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Breast feeding

• Progestogen-Only Injectables DMPA and NET-EN
• Suitable for women who are breastfeeding at 6
  weeks postpartum.
• Combined Injectables Mesigyna
• Not suitable for women who are fully breast
  feeding until 6 months postpartum.

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Thank you