52 Usha Verma and Neil Verma
effects, the lowest effective dose in OCP has been introduced. Use of LNG in
IUD has also resulted in a reduction of some of the systemic side effects of
LNG due to low-level systemic levels.
The side effects depend on whether the progestin is combined with
estrogen or is used alone. Some side effects may be due to blockage of
follicular maturation, resulting in a decrease in endogenous estrogen
production. In addition, the side effects of progestin may be associated to its
estrogenic effects or its androgenic or glucocorticoid properties [6]. The side
effects are usually related to the combined effects of estrogen and
progesterone in combined products, or are related to higher doses of
medroxyprogesterone, LNG or norethindrone acetate.
The usual side effects reported with progestins are bleeding problems,
headaches, bloating, mastalgia, weight gain, mood changes and acne [99, 100].
Not all progestins cause the same side effects and to the same degree. OCP-
containing levonorgestrel is quite effective in regulating the menstrual cycle
but with levonorgestrel-containing implants (Norplant) and LNG-IUD,
menstrual irregularity is one of the common side effects. With Norplant
approximately 20 and 30% of users experience irregular, unpredictable uterine
bleeding [101-106]. Irregular bleeding is the main side effect associated with
the use of Norplant. The extent of uterine bleeding, even though it can be
persistent and prolonged, is usually not clinically significant and does not
cause anemia or a significant drop in hemoglobin concentrations. Rather, a rise
in the hemoglobin concentrations has been reported in Norplant users [107].
Unpredictable uterine bleeding or spotting, which occurs often and for >5- 6
days, interferes with personal life rather than being a problem of any medical
significance.
Menstrual irregularity is also the most common side effect of LNG-IUD.
Women may experience irregular bleeding in the beginning followed by
oligomenorrhea or amenorrhea. Practically 25% of women discontinue using
the LNG-IUD because of amenorrhea [54]. Approximately 20% of LNG-IUD
users will be amenorrheic by the end of 12 months [108], and 70% of users
will be oligomenorrheic or amenorrheic by 24 months [109]. Overall the LNG-
IUD is well tolerated.
Baldaszti et al. evaluated the long-term acceptability of the LNG-IUD in
165 women over 3 years. The study showed a three-year continuation rate of
90.3%. The number of women who expressed that they were very satisfied
with the LNG-IUD increased steadily with the duration of the treatment, 29%
after two weeks, 56% after two months, 69% after six months and 77% after
36 months [110].