desogestrel + ethinylestradiol: clinical use

Prescribing considerations

• Assess thromboembolic history, migraine features, smoking, blood pressure, body mass, postpartum status, planned surgery or immobilisation, hepatic disease and interacting medicines.
• Desogestrel-containing combined hormonal contraceptives have a higher estimated VTE risk than preparations containing levonorgestrel, norgestimate or norethisterone.
• Exclude pregnancy and investigate unexplained vaginal bleeding before prescribing.
• Discuss STI protection, missed tablets, gastrointestinal disturbance and symptoms requiring urgent assessment.

Contraindications and cautions

• Current or previous venous or arterial thromboembolism, relevant thrombophilia, major surgery with prolonged immobilisation or sufficiently high combined thrombotic risk
• Migraine with focal neurological symptoms
• Severe hypertension, diabetes with vascular disease or severe dyslipidaemia creating high arterial risk
• Severe active liver disease, liver tumours, pancreatitis associated with severe hypertriglyceridaemia or suspected oestrogen-dependent malignancy
• Pregnancy, unexplained vaginal bleeding, endometrial hyperplasia or hypersensitivity to an ingredient
• Concomitant use of specified hepatitis C antiviral combinations described in the individual product information

Monitoring

• Measure blood pressure before initiation and reassess cardiovascular and thrombotic risk factors at routine reviews.
• Review persistent or newly occurring irregular bleeding after previously stable cycles and exclude pregnancy or other pathology where appropriate.
• Review new migraine, neurological symptoms, sustained hypertension, significant mood deterioration or hepatic dysfunction promptly.
• Routine laboratory monitoring is not generally required solely for contraception, but contraceptive steroids can alter some biochemical and coagulation test results.

Clinical pharmacology

Desogestrel is rapidly converted to etonogestrel, which provides progestogenic suppression of ovulation. Ethinylestradiol contributes ovarian suppression and increases sex hormone-binding globulin; both undergo hepatic metabolism, including CYP3A4 pathways.

Formulation and product differences

• Cimizt contains desogestrel 150 micrograms with ethinylestradiol 30 micrograms in an uncoated tablet containing lactose.
• Mercilon contains desogestrel 150 micrograms with ethinylestradiol 20 micrograms.
• Products are not automatically interchangeable: confirm strength, excipients, pack and current product information.

Tablet

Route: Oral

Strengths: 20 micrograms + 150 micrograms, 30 micrograms + 150 micrograms, 150 micrograms + 20 micrograms, 150 micrograms + 30 micrograms