Introduction

Levonorgestrel is a synthetic progestogen. At an increased dose, levonorgestrel could prevent pregnancy by delaying release of ovum (egg) from the ovary, interfering with fertilisation of ovum by sperm or interfering with implantation of fertilised ovum into the uterine wall. In fact, fertilisation seldom occurs right after a sexual intercourse. More often, it occurs several hours after ovulation. Between sexual intercourse and fertilisation, sperms are moving towards the Fallopian tube to meet the ovum. This is the basis on which this oral contraceptive works, which is preventing fertilisation and implantation due to the effect of progestin.

There are several products of levonorgestrel 0.75mg tablet which are registered with the Drug Control Authority under various proprietary names for Malaysian market.

Use of Medication

Levonorgestrel 0.75mg tablet is taken after sexual intercourse to prevent pregnancy. It is used to prevent unplanned pregnancy following an unprotected sex or in the events of contraceptive failure such as condom defect.

LEVONORGESTREL 0.75MG ONLY PREVENTS OCCURRENCE OF PREGNANCY BUT HAS NO EFFECT ON A PREGNANCY THAT HAS ALREADY ESTABLISHED.

Levonorgestrel 0.75mg is not recommended as the main method of contraception. Its use should be limited to isolated cases where there are failures of routine/common contraception methods. Levonorgestrel 0.75mg can also be used as an additional method of contraception if someone is not sure whether the contraceptive method she usually uses is effective.

Contraindication

• Levonorgestrel 0.75mg should not be taken by pregnant women or women with suspected pregnancy.
• If consumed by women who are already pregnant, levonorgestrel 0.75mg has no effect on avoidance of pregnancy. It is unlikely to cause abortion.
  

Precautions

• Levonorgestrel is excreted into breast milk. Therefore, a mother is recommended to breastfeed her baby as soon as possible before consuming levonorgestrel 0.75mg and not to breastfeed the baby for at least 8 hours after consuming this medication.
• Women who become pregnant or complain of lower abdominal pain after consuming levonorgestrel 0.75mg tablet should be examined to rule out ectopic pregnancy.
• Levonorgestrel may interfere with menstrual cycle. If menstruation has delayed for one week from the expected date, the possibility of pregnancy should be considered.

Special Instructions for Medication Intake

• The first dose of levonorgestrel should be taken within 72 hours (3 days) after unprotected sexual intercourse. The second dose should be taken 12 hours after the first dose without compromising efficacy. You should not delay starting treatment.
• The effectiveness of levonorgestrel is higher if the first dose is taken as soon as possible after a sexual intercourse.
• If vomiting occurs within two hours after medication intake, the dose should be repeated to ensure effectiveness.
• This medication could be taken with or without meal.
  

Side Effects

Like other medications which contain a progestogen, levonorgestrel 0.75mg tablet might cause side effects such as nausea, vomiting, bleeding between menstruations, breast tenderness, headache, dizziness and fatigue.

Drug Interactions

The effectiveness of levonorgestrel might be reduced if it is taken together with certain medications such as ampicillin, rifampicin, chloramphenicol, neomycin, sulphonamide, tetracycline, barbiturate and phenylbutazone.

Control by Law

Levonorgestrel 0.75mg tablet is listed as Group C poison in the First Schedule of Poison Act 1952, which could only be obtained from a registered medical practitioner or pharmacist.

Picture

Here are some examples of tablet containing levonorgestrel 0.75mg which usually supplied with 2 tablets per strip for easy consumption. The appearance of the tablets might differ, depending on the brand of the medicines.

References

1. First Schedule – Poisons List. Poisons Act 1952. Cited on 14 March 2014 from http://www.pharmacy.gov.my/v2/sites/default/files/document-upload/ poisons-list_0.pdf

2. Levonorgestrel tablets, 0.75 mg. Information for Pharmacists. Cited on 14 March 2014 from http://www.levo4u.com/pdf/pharmacist_info.pdf

3. Official Portal National Pharmaceutical Control Bureau, Ministry of Health Malaysia. Information on Product Searches. http://portal.bpfk.gov.my/index.cfm?&menuid=47 (last updated on 19 March 2014)

4. Postinor-2. MIMS Malaysia. Cited on 6 March 2014 from http://www.mims.com/malaysia/drug/info/Postinor-2/