Indications/Uses
Listed in Dosage.
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Dosage/Direction for Use
Adult : PO Contraception Monotherapy: 30 or 37.5 mcg/day. Monophasic combined oral contraceptive (COC): 150-250 mcg/day. Triphasic COC: 50-125 mcg/day. Emergency contraception 1.5 mg w/in 72 hr of coitus or 750 mcg immediately or w/in 72 hr of coitus, then a 2nd dose 12 hr later. Menopausal HRT As progestogenic component: 75-250 mcg/day for 10-12 days of 28-day cycle. SC Contraception Insert 6 implants (36 mg/implant) under the skin w/in the 1st 7 days of the menstrual cycle, replace 5 yrly. Intrauterine Contraception; Menorrhagia 52 mg released at an initial rate of 20 mcg/day. Replace after 5 yr. Trandermal Menopausal HRT As combined transdermal patch (10 mcg/24 hr w/ an oestrogen): Apply once wkly for 2 wk for a 4-wk cycle. As combined transdermal patch (7 or 15 mcg/24 hr w/ an oestrogen): Apply once wkly for continuous HRT.
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Dosage Details
Intrauterine
Contraception, Menorrhagia Adult: 52 mg released at an initial rate of 20 mcg/day. System is effective for up to 5 yr. Oral Contraception Adult: Monotherapy: 30 or 37.5 mcg daily. Monophasic combined oral contraceptive (COC): 150-250 mcg daily. Triphasic COC: 50-125 mcg daily. Oral Emergency contraception Adult: 1.5 mg as soon as possible or within 72 hr of coitus. Alternatively, 750 mcg as soon as possible or within 72 hr of coitus followed by a 2nd dose 12 hr later. Another regimen combines levonorgestrel 500 mcg and ethinylestradiol 100 mcg; may be given within 72 hr of coitus followed by a 2nd dose 12 hr later. Oral Menopausal hormone replacement therapy Adult: As progestogenic component: 75-250 mcg for 10-12 days of a 28-day cycle. Subcutaneous Contraception Adult: Insert 6 implants (36 mg/implant) under the skin within the first 7 days of the menstrual cycle and replace at intervals of up to 5 yr. Transdermal Menopausal hormone replacement therapy Adult: As combined transdermal patch (releases 10 mcg/24 hr with an oestrogen): Apply once wkly for 2 wk of a 4-wk cycle. Alternatively, a patch releasing 7 or 15 mcg/24 hr with an oestrogen is applied once wkly for continuous HRT.
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Administration
May be taken with or without food.
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Contraindications
Pregnancy, undiagnosed vaginal bleeding, severe arterial disease; liver adenoma, porphyria; after recent evacuation of hydatidiform mole; history of breast cancer; hepatic impairment.
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Special Precautions
Sex-steroid dependent cancer, past ectopic pregnancy, malabsorption syndromes, functional ovarian cysts, active liver disease, recurrent cholestatic jaundice, history of jaundice in pregnancy, CV or renal impairment, DM, asthma, epilepsy, migraine, conditions aggravated by fluid retention, depression and thromboembolism (high doses); lactation.
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Adverse Reactions
Menstrual irregularities; nausea, vomiting, headache, dizziness, breast discomfort, gynaecomastia, depression, skin disorders, disturbance of appetite, wt changes, fluid retention, oedema, changes in libido, cholestatic jaundice, hair loss or hirsutism. Benign intracranial hypertension, thrombocytopenic purpura.
Potentially Fatal: Thrombocytopenia, stroke. |
Drug Interactions
Reduced efficacy with enzyme-inducing drugs; aminoglutethimide. May inhibit ciclosporin metabolism.
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Lab Interference
May interfere with laboratory tests e.g. liver, renal, thyroid and adrenal function tests, plasma levels of binding proteins and lipid/lipoprotein fractions, and fibrinolysis and coagulation parameters.
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Action
Description: Levonorgestrel, a nortestosterone derivative, is an active isomer of norgestrel. It is a potent inhibitor of ovulation and has androgenic activity.
Pharmacokinetics: Absorption: Rapid and almost complete from the GI tract (oral). Distribution: Protein-binding: 42-68% (sex binding globulin), 30-56% (albumin). Distributed into breast milk. Metabolism: Hepatic; converted to sulfate and glucuronide conjugates. Excretion: Via urine and via faeces (lesser extent). |
Storage
Intrauterine:
Store at 25°C (77°F). Oral: Contraception: Store at 20-25°C (68-77°F). |