ethinylestradiol + norelgestromin: clinical use

Prescribing considerations

• Assess individual venous and arterial thromboembolism risk and compare it with other combined hormonal contraceptives.
• Take a personal and family medical history, exclude pregnancy and measure blood pressure before initiation or re-initiation.
• Review smoking, migraine, body mass, planned surgery or immobilisation, cardiovascular risks, liver disease and interacting medicines.
• Contraceptive efficacy may be reduced at body weights of 90 kg or more.
• Safety and efficacy have not been established below age 18; the product is not intended for post-menopausal use or hormone replacement therapy.

Contraindications and cautions

• Current or previous venous thromboembolism, thrombophilia, major surgery with prolonged immobilisation or otherwise high VTE risk.
• Current or previous arterial thrombosis, stroke or transient ischaemic attack; migraine with focal neurological symptoms; or high arterial-thrombosis risk.
• Severe hypertension, diabetes with vascular complications or severe dyslipoproteinaemia.
• Known or suspected breast cancer, endometrial cancer or another oestrogen-dependent tumour.
• Acute or chronic hepatocellular disease with abnormal liver function, or hepatic adenoma or carcinoma.
• Unexplained genital bleeding, hypersensitivity to an ingredient, or specified interacting hepatitis C treatment.

Monitoring

• Reassess blood pressure and evolving thrombotic or cardiovascular risk factors.
• Review new or worsening migraine, mood disturbance, significant skin reactions or symptoms suggesting liver disease.
• Investigate persistent or newly abnormal bleeding after previously stable use, considering pregnancy and non-hormonal causes.
• Review adherence and medicine interactions if bleeding changes or contraceptive failure is suspected.

Clinical pharmacology

Norelgestromin and ethinylestradiol are absorbed through the skin. Their progestogenic and oestrogenic effects suppress gonadotropins and principally inhibit ovulation; cervical-mucus and endometrial changes also contribute. Both undergo hepatic metabolism, with metabolites eliminated through renal and faecal routes.

Formulation and product differences

• The selected product is a thin, beige, three-layer matrix transdermal patch.
• It should not be cut or altered because this may compromise contraceptive effectiveness.
• Exposure from a transdermal combined contraceptive should not be directly equated with oral contraceptive pharmacokinetics.

Transdermal patch

Route: Transdermal

Strengths: 203 micrograms/24 hours + 33.9 micrograms/24 hours