Subdermal implants for long term contraception

Though injectable contraceptives are a boon for those who have a busy daily schedule and often forget and missed their oral pills. These injectable contraceptives though is better in compliance but have certain advantages and disadvantages.

But monthly injecttions was too intolerable for some women and that lead to exploration of other route of progesterone delivery havin slow and sustained release, longer in action and fewer in side effects. Then came subdermal implants as a long acting contraceptive measure.

Subdermal implants for long term contraception

Though there are misconceptions about subdermal implants but it has no adverse value in fact it is more effective than oral contraceptive pills having lesser side effects as it avoids hepatic first pass metabolism.

The different types of subdermal implants frequently used are-

Norplant

Norplant consists of two rods each containing 70 mg levonorgesterol which releases 50 microgram daily and once implanted acts for 3 to 5 years.

It acts by suppressing endometrium and 50% by suppressing ovulation. It is implanted on medial side of upper arm under local anaesthesia.

The best timing of implantation is on the first day of menstrual cycle, or within 5 days following an abortion or 3 weeks after delivery. A barrier contraception should be used for the first week as it may take a week to act to its maximum.

The main disadvantage of Norplant is that it needs removal at the end of the use and if there is intolerable side effects.

Implanton is an implant where single rod is used and is effective for 3 years, though it also needs to be removed.

Capronor is an implant which doesnt require removal as it consist of a single biodegradable capsule containing levonorgestrel and its effect last for one year.

The return of fertility occurs in about 40 percent within 3 months of removal and to 90 % in about 2 years. In about 10% it may require request removal because of side effects or wishing for a child.

Advantages of dermal implants

The main advantage is that it is long acting and have sustained effect, it is coital independent and there is no requirement of frequent injections or daily dose of pills.

Pregnancy rate is too low as it is quiet effective method of contraception. As it avoids hepatic first pass thus systemic side effects are too low.

It can be safely used in lactating women and at all ages even at age over 40 years.

Disadvantages of dermal implant

The most disturbing disadvantage which can lead to request removal is breakthrough bleeding. There may be amennorhea and irregular cycles as happens with progesterones.

In some cases about 1 in 100 there is report of ectopic pregnancy, infertility may occur in few cases and the other side effect of progesterone may exist.

There may be local infection at the implant site though this can be avoided by maintaining hygiene.

One disadvantage is that it requires both insertion and removal, though now a days biodegradable capsules are available like Capronor which does not require removal.

Norplants are too costly for a normal person to bear, thus it is not so popular in developing countries like India.

Subdermal implants for long term contraception