Norethisterone

Please note: these are basic guidelines, refer to your doctor for a professional medical opinion.

Popular brand names:

[tablets] Micro-Novum, Primolut N

[injection], Nur-Isterate  

Popular combinations:

[tabs] Activelle, Estro-pause N, Kliogest, Novofem, Trinovum, Trisequens

[patches] Estalis, Evorel (conti/sequi)

Drug group:

Female sex hormone

Prescription needed?

Yes

What does it do?

Norethisterone has a wide variety of uses including:

• Contraception: oral (alone or with oestrogen); injectable (alone)
• Postponement of menstruation
• Treatment of menstrual disorders like endometriosis: taken only on certain days during the menstrual cycle
• Hormone replacement therapy (HRT): in combination with oestrogen, usually only advised for short-term use around the menopause, not recommended for treatment of osteoporosis
• Used in the treatment of certain breast cancers

How does it work?

Norethisterone is a synthetic form of the natural female sex hormone progesterone.

What is the typical dosage?

Your doctor will recommend a dosage tailored to your need, but typically:

• Contraception: tablets 350mcg daily, skin patch 2x weekly, injection once every 8 weeks
• Postponement of menstruation: 5mg 3xdaily, started 1-2 days before expected period, normal period should occur 2-3 days after stopping the drug
• Menstrual disorders: tablets, 10–15mg daily
• HRT: 700mcg–1mg daily
• Cancer: 30–60mg daily

How quickly will it start to work?

Within a few hours             
            

How long will the effects last?

24 hours                  

When should I stop using it?

Contraception: can be safely stopped as soon as no longer needed.

Other uses: do not stop taking without discussing with your doctor.     
                          

Is it safe for prolonged use?

Long term use can rarely lead to liver damage.

Hormone replacement therapy (HRT) in postmenopausal women increases the risk of venous thrombosis and breast cancer - the breast cancer risk reduces after stopping the drug, and disappears entirely after 10 years. Regular blood-pressure checks, physical examinations and mammograms may be performed.                 

What are the possible side effects?

The following have been reported:

• More common: breakthrough bleeding (oral contraceptives)
• Less common: swelling of the ankles/feet, weight gain, acne, skin discoloration, headaches
• Report to your doctor before taking your next dose if you experience: depression, pain/tightness in the chest, disturbances of vision/hearing, jaundice

What other considerations are important?

Dosage may be adjusted by your doctor under certain conditions.

• Certain health problems: liver/kidney problems, diabetes, epilepsy/seizures, recurrent migraine, acute porphyria, heart/circulatory problems, history of venous thrombosis
• Other medicines: oral anticoagulants, anticonvulsants, antihypertensives, diabetes medications, antituberculous drugs, certain antivirals, antibiotics, St John’s wort, ciclosporin
• Pregnancy and breast-feeding: Not usually prescribed in pregnancy, amounts passed into breast milk unlikely to affect baby
• Children: Not prescribed
• Over 60: Not usually prescribed
• Driving and hazardous work: No special problems
• Alcohol: No special problems
• Surgery and general anaesthetics: Inform your doctor that you are taking norethisterone