Drug reference

Levonorgestrel

Progestogen · Contraceptive

ProgestogenContraceptive

CDSCO approvedSchedule H

EXCRETION

—

not curated

INTERACTIONS

12 major

SEVERE in our sources

PREGNANCY

FDA category + note

Top interactionssee all 12 →

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Mechanism

Levonorgestrel is a potent synthetic progestogen (13-ethyl-gonane derivative) that suppresses ovulation by inhibiting the mid-cycle luteinizing hormone (LH) surge via hypothalamic-pituitary negative feedback. At contraceptive doses, it also thickens cervical mucus (impeding sperm transport) and induces endometrial atrophy (reducing implantation receptivity). In the levonorgestrel-releasing intrauterine system (LNG-IUS), local progestational effects on the endometrium reduce menstrual blood loss by over 70%, independent of systemic hormonal effects.

Indications

Contraception (as part of levonorgestrel-releasing intra-uterine system, combined oral contraceptives, and progestogen-only contraceptives)Menorrhagia (with levonorgestrel-releasing intra-uterine system, particularly if contraception is also required)Severe dysmenorrhoea (especially when contraception is also required in younger women)hormonal contraceptiontransdermal contraception (with ethinyl estradiol)intravaginal contraception (with ethinyl estradiol)intrauterine system (IUS) for contraceptionpostcoital contraception (emergency contraception)menorrhagia (off-label with IUS)endometriosis (off-label with IUS)Progestin therapyCombined oral contraceptivesEmergency contraceptionMinipill (progestin-only pill)Implants

Dosing

Adult: concentration of 10.2 g/100 mL (102 g/litre) or less. If the. haemoglobin concentration is more than 10.2 g/100 mL. (102 g/litre), ulipristal acetate may be considered. The use of. excessive menstrual blood loss of 80 mL or more, or for a. Adult: 60 mg once daily

Pharmacokinetics

Metabolism

Levonorgestrel is a component of combined oral contraceptive pills and its metabolism can be increased by enzyme inducers like rifampin.

Contraindications

Dysphasia
Bad fainting attack or collapse
First unexplained epileptic seizure
Weakness, motor disturbances, very marked numbness suddenly affecting one side or one part of body
Hepatitis
Jaundice
Liver enlargement
Blood pressure above systolic 160 mmHg or diastolic 95 mmHg
Prolonged immobility after surgery or leg injury
Detection of a risk factor which contra-indicates treatment
Prevention of miscarriage (not recommended)
undiagnosed vaginal bleeding
benign or malignant liver disease
known or suspected breast cancer
severe uterine distortion (for IUD)
active pelvic infection (for IUD)
unexplained abnormal uterine bleeding (for IUD)
Use for diagnosis of pregnancy
Early pregnancy (can cause masculinization of female foetus and other congenital abnormalities)
Long-term HRT (may increase risk of breast cancer)

Side effects

Common

hirsutismacneweight changenauseaheadachemood changebreast tendernessirregular bleeding (initial)amenorrheaAndrogenic activityAnabolic activityAntiestrogenic activityBreast engorgement (with higher doses)Headache (with higher doses)Rise in body temperature (with higher doses)Edema (with higher doses)Esophageal reflux (with higher doses)Acne (with higher doses)Mood swings (with higher doses)Next period may be delayed or disrupted (emergency contraception)

Serious

Blood sugar may rise and diabetes may be precipitated by long-term use
Masculinization of female foetus and other congenital abnormalities (if given in early pregnancy)
Long-term use in HRT may increase the risk of breast cancer