Levonorgestrel

Description

Levonorgestrel is a synthetic progestin primarily used as a contraceptive. It is often utilized in emergency contraception and is known to work by preventing ovulation, inhibiting fertilization, and altering the uterine lining to prevent implantation of a fertilized egg.

Uses / Indications

• Emergency contraception (Postcoital contraceptive)
• Long-term contraceptive (as part of combination hormonal contraceptive pills)
• Management of menstrual disorders (e.g., heavy menstrual bleeding)
• Endometrial protection during hormone replacement therapy

Dosage and Administration

Emergency contraception:
1.5 mg taken as a single dose within 72 hours of unprotected intercourse.

For regular contraceptive use:
Typically taken as part of a multi-dose regimen in combination with estrogen, or as directed by a healthcare provider.

Note: Dosage may vary based on individual circumstances and medical advice.

How It Works (Mechanism of Action)

Levonorgestrel primarily functions by inhibiting or delaying ovulation. It may also thicken cervical mucus to prevent sperm from reaching an egg and alter the endometrium to prevent implantation. Its effectiveness is highest when taken as soon as possible after unprotected intercourse.

Side Effects

Common side effects:

• Nausea
• Fatigue
• Headache
• Breast tenderness
• Changes in menstrual bleeding

Rare/serious side effects:

• Severe allergic reactions (rash, itching, swelling)
• Abdominal pain (intense)
• Menstrual changes (prolonged bleeding)

Seek medical attention if serious side effects occur.

Precautions / Warnings

• Consult your doctor if you have a history of blood clots, liver disease, or reproductive cancers.
• It is not recommended for use in everyone; a thorough medical history should be reviewed.
• Should not be used as a regular contraceptive method; it’s intended for emergency use only.
• Not effective if a woman is already pregnant.

Drug Interactions

May interact with:

• Certain anti-seizure medications (may reduce effectiveness)
• Antibiotics (e.g., rifampin)
• Herbal supplements (e.g., St. John’s Wort)

Always inform your healthcare provider about any other medications or supplements you are taking.

Storage Instructions

• Store at room temperature (20°C–25°C / 68°F–77°F)
• Keep away from moisture, heat, and direct light
• Keep out of reach of children

Missed Dose / Overdose

Missed a dose?
For emergency contraception, if a dose is missed, it should be taken as soon as possible. If beyond the recommended 72 hours, the pill is not effective.

Overdose symptoms:

• Severe nausea
• Vomiting
• Altered menstrual cycle

If overdose is suspected, seek medical help immediately.

Contraindications

• Allergic to Levonorgestrel or any component of the formulation
• Pregnancy (confirmed)
• History of hormone-sensitive cancers

Brand Names / Alternatives

• Plan B One-Step
• Next Choice
• Mirena (intrauterine system)
• Skyla (intrauterine system)
• Generic name: Levonorgestrel