Will Depo-Provera suit you?

Most women who use Depo-Provera find this method of contraception to be fully acceptable, however, not all women should use Depo-Provera.

You should not use Depo-Provera for contraception if you have any of the following conditions:

• if you have had cancer of the breast or sex organs;
• if you have unusual vaginal bleeding the cause of which is unknown;
• if you are allergic to medroxyprogesterone acetate or any of the other ingredients of Depo-Provera;
• if you think you may be pregnant;
• if you have not started getting your periods;
• if you are using certain medicines such as high dose glucocorticoids (steroids), anti-epileptics, and thyroid hormones. Tell the person who provides your contraception if you are taking these or any other medicines - they may recommend a more suitable method of contraception.

How will Depo-Provera affect my periods?

Depo-Provera usually disturbs the pattern of women’s periods.

After the first injection it is most likely that you will have irregular, possibly lengthy bleeding or spotting. This continues in some women. This is quite normal and nothing to worry about.

One third of women will not have any bleeding at all after the first injection. After 4 injections, most women find that their periods have stopped completely. Not having periods is nothing to worry about.

If you experience very heavy or prolonged bleeding you should talk to your doctor. This happens rarely but can be treated easily.

When you stop using Depo-Provera your periods will return to normal in a few months.

What if I want a baby?

Your usual level of fertility will return when the effect of the injection has worn off. This takes different times in different women, and does not depend on how long you have been using Depo-Provera. In most women the effect will have worn off 5 to 6 months after the last injection. Over 80 % of women will conceive within a year of the first missed injection.

Pregnancies have been recorded in the first month after missing an injection.

Will I put on weight?

Some women gained weight while using Depo-Provera. Studies show that over the first 1-2 years of use, the average weight gain was 5-8 lbs. Women completing 4-6 years of therapy gained an average of 14-16.5 lbs.

What about cancer risks?

Studies of women who have used different forms of contraception found that women who used Depo-Provera for contraception had no increased overall risk of developing cancer of the ovary, womb, cervix, or liver.

Every woman is at risk of breast cancer whether or not she receives injections of medicines like Depo-Provera. Breast cancer is rare under 40 years of age, but the risk increases as a woman becomes older.

There seems to be a slightly increased risk of breast cancer in women who take injectable contraceptives compared to women of the same age who do not use hormonal contraceptives.

This small extra risk of developing breast cancer has to be weighed against the known benefits of medicines like Depo-Provera. It is not certain whether the injection causes the increased risk of breast cancer. It may be that women receiving the injection are examined more often, so that breast cancer is noticed earlier. The breast cancer seems less likely to have spread when found in women who receive medicines like Depo-Provera than in women who do not.

The risk of finding breast cancer is not affected by how long a woman is on the injection, but by the age at which she stops. This is because the risk of breast cancer strongly increases as a woman becomes older. Ten years after stopping hormonal contraceptive injections, the risk of finding breast cancer is the same as for women who have never used hormonal contraceptives.

In 10, 000 women who receive injections like Depo-Provera for up to 5 years, but stop taking it by the time they are aged 20, it is estimated that less than 1 additional case of breast cancer would be found up to 10 years afterwards, compared with the number found in 10,000 women who had never had the injection.

For 10, 000 women who are on injections like Depo-Provera for 5 years and stop it by the age of 30, there would be 2 or 3 extra cases of breast cancer found up to 10 years afterwards (in addition to the 44 cases of breast cancer found in 10,000 women in this age group who had never had the injection).

For 10, 000 women who take Depo-Provera for 5 years and stop it by the age of 40, there would be about 10 extra cases found up to 10 years afterwards (in addition to 160 cases of breast cancer found in 10,000 women in this age group who had never had the injection).

Will Depo-Provera affect my bones?

Depo-Provera works by lowering levels of oestrogen and other hormones. However, low oestrogen levels can cause bones to become thinner (by reducing bone mineral density). Women who use Depo-Provera tend to have lower bone mineral density than women of the same age who have never used it. The effects of Depo-Provera are greatest in the first 2-3 years of use. Following this, bone mineral density tends to stabilise and there appears to be some recovery when Depo-Provera is stopped. Research is being carried out to find out how completely the bones recover after long-term use of Depo-Provera. It is not yet known whether the effect of Depo-Provera on bone mineral density increases the risk of osteoporosis (weak bones) and fractures in later life.

Teenagers (up to 18 years): Normally, the bones of teenagers are rapidly growing and increasing in strength. The stronger the bones are when adulthood is reached, the greater the protection against osteoporosis in later life. Since Depo-Provera may cause teenage bones to become thinner at a time when they should be growing, its effect may be particularly important in this age group. Bones start to recover when Depo-Provera is stopped, but it is not yet known whether the bone mineral density reaches the same levels as it would have if Depo-Provera had never been used. You should therefore discuss whether another form of contraception might be more suitable for you with the person who provides your contraception before starting Depo-Provera.

If you use Depo-Provera, it may help your bones if you take regular weight-bearing exercise and have a healthy diet, including an adequate intake of calcium (e.g. in dairy products) and vitamin D (e.g. in oily fish).

Is there a risk of infection at the injection site?

As with any intramuscular injection, there is a risk of an infection at the site of injection. This may require medical or surgical attention.

Could I be allergic to Depo-Provera?

There is a very low risk of severe allergic reactions.

Taking other medicines

Tell your doctor if you are taking aminoglutethimide as this may affect the way your Depo-Provera works. Also tell your doctor if you are taking any other medicines. This includes ’over the counter’ medicines from the pharmacy (chemist).

Tell any other doctor who treats you that you are using Depo-Provera as a contraceptive.

Are you breastfeeding?

Although Depo-Provera can be passed to the nursing infant in the breast milk, no harmful effects have been found in these children. Depo-Provera does not prevent the breasts from producing milk, so it can be used by nursing mothers.

It is better for the baby that for the first few weeks after birth its mother’s milk contains no traces of any medicines, including Depo-Provera. Your doctor may suggest that you wait until at least 6 weeks after your baby has been born before you start using Depo-Provera for contraception.

Are you having any laboratory tests done?

If you are scheduled for any laboratory tests, tell your doctor or nurse that you are using Depo-Provera for contraception. Certain blood tests are affected by hormones such as Depo-Provera. This also applies if a sample of tissue is taken from your womb (D&C), cervix or vagina for examination.

Can I become pregnant?

Because Depo-Provera is such an effective contraceptive method, the risk of accidental pregnancy for women who have their injections regularly (every 12 weeks) is very low. If you think you may have become pregnant while using Depo-Provera for contraception, see your doctor.

Warnings:

Loss of Bone Mineral Density: Use of Depo-Provera injection reduces serum oestrogen levels and is associated with significant loss of BMD due to the known effect of oestrogen deficiency on the bone remodelling system. Bone loss is greater with increasing duration of use and appears to be at least partially reversible after Depo-Provera injection is discontinued and ovarian oestrogen production increases.

This loss of BMD is of particular concern during adolescence and early adulthood, a critical period of bone accretion (see section 4.1, Therapeutic Indications). It is unknown if use of Depo-Provera injection by adolescent women will reduce peak bone mass and increase the risk for osteoporotic fracture in later life. A study to assess the reversibility of loss of BMD in adolescent females is ongoing. In adolescents, Depo-Provera may be used, but only after other methods of contraception have been discussed with the patients and considered to be unsuitable or unacceptable. In women of all ages, careful re-evaluation of the risks and benefits of treatment should be carried out in those who wish to continue use for more than 2 years. In women with significant lifestyle and/or medical risk factors for osteoporosis, other methods of contraception should be considered prior to use of Depo-Provera.

Menstrual Irregularity: The administration of Depo-Provera usually causes disruption of the normal menstrual cycle. Bleeding patterns include amenorrhoea (present in up to 30 % of women during the first 3 months and increasing to 55 % by month 12 and 68 % by month 24); irregular bleeding and spotting; prolonged (›10 days) episodes of bleeding (up to 33 % of women in the first 3 months of use decreasing to 12 % by month 12). Rarely, heavy prolonged bleeding may occur. Evidence suggests that prolonged or heavy bleeding requiring treatment may occur in 0.5-4 occasions per 100 women years of use. If abnormal bleeding persists or is severe, appropriate investigation should take place to rule out the possibility of organic pathology and appropriate treatment should be instituted when necessary.

Excessive or prolonged bleeding can be controlled by the co-administration of oestrogen. This may be delivered either in the form of a low dose (30 micrograms oestrogen) combined oral contraceptive pill or in the form of oestrogen replacement therapy such as conjugated equine oestrogen (0.625-1.25 mg daily). Oestrogen therapy may need to be repeated for 1-2 cycles. Long-term co-administration of oestrogen is not recommended.

Return to Fertility: There is no evidence that Depo-Provera causes permanent infertility. Pregnancies have occurred as early as 14 weeks after a preceding injection, however, in clinical trials, the mean time to return of ovulation was 5.3 months following the preceding injection. Women should be counselled that there is a potential for delay in return to full fertility following use of the method, regardless of the duration of use, however, 83 % of women may be expected to conceive within 12 months of the first "missed" injection (i.e. 15 months after the last injection administered). The median time to conception was 10 months (range 4-31) after the last injection.

Cancer Risks: Long-term case-controlled surveillance of Depo-Provera users found no overall increased risk of ovarian, liver, or cervical cancer and a prolonged, protective effect of reducing the risk of endometrial cancer in the population of users. A meta-analysis in 1996 from 54 epidemiological studies reported that there is a slight increased relative risk of having breast cancer diagnosed in women who are currently using hormonal contraceptives. The observed pattern of increased risk may be due to anearlier diagnosis of breast cancer in hormonal contraceptive users, biological effects or a combination of both. The additional breast cancers diagnosed in current users of hormonal contraceptives or in women who have used them in the last ten years are more likely to be localised to the breast than those in women who never used hormonal contraceptives.

Breast cancer is rare among women under 40 years of age whether or not they use hormonal contraceptives. In the meta-analysis the results for injectable progestogens (1.5 % of the data) and progestogen only pills (0.8 % of the data) did not reach significance although there was no evidence that they differed from other hormonal contraceptives. Whilst the background risk of breast cancer increases with age, the excess number of breast cancer diagnoses in current and recent injectableprogestogen (IP) users is small in relation to the overall risk of breast cancer, possibly of similar magnitude to that associated with combined oral contraceptives., For IPs, however, the evidence is based on much smaller populations of users (less than 1.5 % of the data) and is less conclusive than for combined oral contraceptives. It is not possible to infer from these data whether it is due to an earlier diagnosis of breast cancer in ever-users, the biological effects of hormonal contraceptives, or a combination of reasons.

The most important risk factor for breast cancer in IP users is the age women discontinue the IP; the older the age at stopping, the more breast cancers are diagnosed. Duration of use is less important and the excess risk gradually disappears during the course of the 10 years after stopping IP use, such that by 10 years there appears to be no excess.

The evidence suggests that compared with never-users, among 10,000 women who use IPs for up to 5 years but stop by age 20, there would be much less than 1 extra case of breast cancer diagnosed up to 10 years afterwards. For those stopping by age 30 after 5 years use of the IP, there would be an estimated 2-3 extra cases (additional to the 44 cases of breast cancer per 10,000 women in this age group never exposed to oral contraceptives). For those stopping by age 40 after 5 years use, there would be an estimated 10 extra cases diagnosed up to 10 years afterwards (additional to the 160 cases of breast cancer per 10,000 never-exposed women in this age group).

It is important to inform patients that users of all hormonal contraceptives appear to have a small increase in the risk of being diagnosed with breast cancer, compared with non-users of hormonal contraceptives, but that this has to be weighed against the known benefits.

Weight Gain: There is a tendency for women to gain weight while on Depo-Provera therapy. Studies indicate that over the first 1-2 years of use, average weight gain was 5-8 lbs. Women completing 4-6 years of therapy gained an average of 14-16.5 lbs. There is evidence that weight is gained as a result of increased fat and is not secondary to an anabolic effect or fluid retention.

Anaphylaxis: Very few reports of anaphylactoid reactions have been received.

Thrombo-embolic Disorders: Should the patient experience pulmonary embolism, cerebrovascular disease or retinal thrombosis while receiving Depo-Provera, the drug should not be readministered.

Psychiatric Disorders: Patients with a history of endogenous depression should be carefully monitored. Some patients may complain of premenstrual-type depression while on Depo-Provera therapy.

Abscess formation: As with any intramuscular injection, especially if not administered correctly, there is a risk of abscess formation at the site of injection, which may require medical and/or surgical intervention.

Precautions:

History or emergence of the following conditions require careful consideration and appropriate investigation: migraine or unusually severe headaches, acute visual disturbances of any kind, pathological changes in liver function and hormone levels. Patients with thromboembolic or coronary vascular disease should be carefully evaluated before using Depo-Provera.

A decrease in glucose tolerance has been observed in some patients treated with progestogens. The mechanism for this decrease is obscure. For this reason, diabetic patients should be carefully monitored while receiving progestogen therapy.

Rare cases of thrombo-embolism have been reported with use of Depo-Provera, but causality has not been established.

The effects of medroxyprogesterone acetate on lipid metabolism have been studied with no clear impact demonstrated. Both increases and decreases in total cholesterol, triglycerides and low-density lipoprotein (LDL) cholesterol have been observed in studies. The use of Depo-Provera appears to be associated with a 15-20 % reduction in serum high density lipoprotein (HDL) cholesterol levels which may protect women from cardiovascular disease. The clinical consequences of this observation are unknown.

The potential for an increased risk of coronary disease should be considered prior to use.

Doctors should carefully consider the use of Depo-Provera in patients with recent trophoblastic disease before levels of human chorionic gonadotrophin have returned to normal.

Physicians should be aware that pathologists should be informed of the patient’s use of Depo-Provera if endometrial or endocervical tissue is submitted for examination.

The results of certain laboratory tests may be affected by the use of Depo-Provera. These include gonadotrophin levels (decreased), plasma progesterone levels (decreased), urinary pregnanediol levels (decreased), plasma oestrogen levels (decreased), plasma cortisol levels (decreased), glucose tolerance test, metyrapone test, liver function tests (may increase), thyroid function tests (protein bound iodine levels may increase and T3 uptake levels may decrease). Coagulation test values for prothrombin (Factor II), and Factors VII, VIII, IX and X may increase.