ALLERCYP

Indications

• Hirsutism in women
• Androgen-dependent neoplasms
• Hormone therapy in transgender women
• Acne vulgaris resistant to other treatments
• Severe alopecia androgenetica

Dosage

Children: Refer to the BNF for Children for age-appropriate dosage recommendations.

Adults: Refer to the BNF for specific dosage guidelines based on the condition being treated.

Mechanism of action

Cyproterone acetate works by blocking the action of androgens at the androgen receptor level, leading to a reduction in the effects of testosterone and other androgens. It also has progestogenic activity, which contributes to its overall effectiveness in hormonal regulation.

Pharmacodynamics

Cyproterone exhibits antiandrogenic and progestogenic properties. By inhibiting the androgen receptor, it reduces the stimulation of androgen-dependent tissues, which can result in decreased sebaceous gland activity and hair growth. Its progestogenic effects can lead to alterations in menstrual cycle regulation and endometrial activity.

Pharmacokinetics

After oral administration, cyproterone is well-absorbed and undergoes extensive hepatic metabolism. The drug has a half-life of approximately 30 to 40 hours, allowing for once-daily dosing in most cases. It is mainly excreted in the urine as metabolites, with only a small percentage eliminated unchanged.

Contra-indications

• Hypersensitivity to cyproterone or any of its components
• Pregnancy
• Active liver disease
• Severe hepatic impairment
• Hormone-sensitive malignancies

Adverse effects

• Headache
• Nausea
• Fatigue
• Weight gain
• Depression
• Gastrointestinal disturbances
• Menstrual irregularities
• Liver function abnormalities

Interactions

• Antiepileptics (carbamazepine, eslicarbazepine, fosphenytoin, oxcarbazepine, perampanel, phenobarbital, phenytoin, primidone, rufinamide, topiramate) - may decrease efficacy
• Modafinil - may decrease efficacy
• Rifamycins - may decrease efficacy
• St John's Wort - may decrease efficacy
• Bosentan - may decrease efficacy
• Ritonavir - may decrease efficacy

Precautions

• Monitor liver function regularly during treatment
• Use with caution in patients with a history of depression
• Consider risk of thromboembolic events
• Assess for potential interactions with other medications

Pregnancy

Cyproterone is contraindicated in pregnancy due to potential harm to the fetus.

Breast-feeding

Due to potential adverse effects on the breastfed infant, cyproterone should be used with caution during breastfeeding.

Storage

Store in a cool, dry place, away from direct light. Keep out of reach of children.

Formulations

• Tablets
• Oral solution

Indications

• Prostate cancer
• Hyperandrogenism conditions such as hirsutism and acne
• Hormonal therapy for breast cancer in women
• Induction and maintenance of sexual maturation in males (specialist use only)

Dosage

Children: For children aged 12–17 years, 40 mg once daily on alternate days, adjusted according to response, with a maximum of 120 mg daily.

Adults: Initially, 250 mg every 2–3 weeks; maintenance 250 mg every 3–6 weeks. For breast cancer, 100 mg 2–3 times a week, adjusted based on clinical response.

Mechanism of action

Cyproterone acetate exerts a direct antiandrogenic effect by blocking the binding of dihydrotestosterone to its receptors in prostatic carcinoma cells. It also inhibits luteinizing hormone secretion through a negative feedback mechanism on the hypothalamo-pituitary axis, leading to reduced testicular testosterone production. Additionally, cyproterone acetate's progestogenic activity further reduces gonadotropin release, decreasing androgen levels and sexual drive.

Pharmacodynamics

As an antiandrogen, cyproterone acetate suppresses the action of androgens on target tissues by blocking androgen receptors and reducing luteinizing hormone levels, which leads to a decrease in testosterone production. This suppression results in decreased cell proliferation in androgen-dependent tissues, including prostate cancer cells.

Pharmacokinetics

Cyproterone acetate is well absorbed following oral administration, with peak plasma concentrations occurring within a few hours. It is highly protein-bound in plasma, primarily to albumin and sex hormone-binding globulin. The drug undergoes extensive hepatic metabolism, with a half-life that allows for once-daily dosing. It is primarily excreted in urine as metabolites, with minimal unchanged drug excreted.

Contra-indications

• Pregnancy
• Severe liver disease
• History of meningioma
• Thrombophilia

Adverse effects

• Diarrhea
• Mood alterations
• Increased appetite
• Arthralgia
• Breast abnormalities
• Cardiovascular disorders
• Cough
• Dysphonia
• Hypercholesterolemia
• Increased risk of infection
• Migraine
• Muscle complaints
• Fluid imbalance
• Gastrointestinal discomfort
• Hepatic function abnormalities
• Lipid metabolism changes
• Myalgia
• Fatigue
• Lassitude

Interactions

• Caution with other medications that affect liver function
• Increased risk of thrombosis when combined with other thrombotic agents

Precautions

• Monitor blood counts initially and throughout treatment
• Monitor hepatic function regularly
• Avoid in patients with a history of hepatic impairment
• Monitor adrenocortical function regularly
• Caution in patients with a history of depression

Pregnancy

Cyproterone acetate is contraindicated in pregnancy due to potential harm to the fetus.

Breast-feeding

Use with caution; consult healthcare providers for advice.

Storage

Store in a cool, dry place, away from direct sunlight. Keep out of reach of children.

Formulations

• Oral tablets
• Solution for injection

Mechanism of action

The direct antiandrogenic effect of cyproterone is blockage of the binding of dihydrotestosterone to the specific receptors in the prostatic carcinoma cell. In addition, cyproterone exerts a negative feed-back on the hypothalamo-pituitary axis, by inhibiting the secretion of luteinizing hormone resulting in diminished production of testicular testosterone. Prostatic carcinoma and its metastases are in general androgen-dependent. Cyproterone acetate exerts a direct anti-androgen action on the tumor and its metastases. It also has progestogenic activity, which exerts a negative feedback effect on the hypothalamic receptors, so leading to a reduction in gonadotrophin release, and hence to diminished production of testicular androgens. Sexual drive and potency are reduced and gonadal function is inhibited. Cell proliferation and cell death appear in several systems as mutually exclusive, which raises the assumption that a same factor or secondary signal(s) might exert opposite control on the two processes. To test this assumption we investigated the time-course evolution of the S phase and apoptotic indices in rat liver during cyproterone acetate (CPA) induced hyperplasia and during the recovery of normal liver mass provoked, respectively, by cyproterone acetate (CPA) treatment and withdrawal. The levels of c-myc and c-ras transcripts were also followed in view of the indications of a positive role of these oncogenes in proliferation. The data showed that proliferation and cell death are not always mutually exclusive and that a high rate of cell death was indifferently associated with high or low c-ras expression. Our data are consistent with a role of this gene in proliferation but exclude that it plays an opposite role in controlling cell death. The antigonadotropic effect of cyproterone acetate is also exerted when administered with LHRH analogues. The initial increase of testosterone caused by this class of substances is reduced by cyproterone acetate. An occasional tendency for the prolactin levels to increase slightly has been observed under higher doses of cyproterone acetate. Dianette blocks androgen-receptors. It also reduces androgen synthesis both by negative feedback effect on the hypothalamo-pituitiary-ovarian systems and by the inhibition of androgen-synthesising enzymes. For more Mechanism of Action (Complete) data for CYPROTERONE ACETATE (8 total), please visit the HSDB record page.

Pharmacodynamics

Cyproterone is an antiandrogen. It suppresses the actions of testosterone (and its metabolite dihydrotestosterone) on tissues. It acts by blocking androgen receptors which prevents androgens from binding to them and suppresses luteinizing hormone (which in turn reduces testosterone levels).