From the Guidelines
Abiraterone should be taken orally once daily in the form of tablets, with the standard dose being 1,000 mg (typically four 250 mg tablets) taken as a single daily dose on an empty stomach, or alternatively, 250 mg/day can be taken after a low-fat breakfast, with concurrent steroid (either oral prednisone 5 mg twice daily or oral methylprednisolone 4 mg twice daily) to reduce side effects. The empty stomach requirement is important because food significantly increases abiraterone absorption, which can lead to higher blood levels and potentially more side effects 1. However, a randomized phase II noninferiority study found that 250 mg/day abiraterone after a low-fat breakfast was noninferior to 1,000 mg/day after an overnight fast in terms of PSA response rate and PFS, and may be considered as an alternative dosing regimen to reduce financial toxicity and improve adherence 1. Patients should swallow the tablets whole with water and should not crush or chew them. It's essential to take abiraterone at approximately the same time each day to maintain consistent blood levels. If a dose is missed, the patient should skip that dose and take the regular dose the next day rather than doubling up. Abiraterone works by blocking an enzyme called CYP17, which is needed for androgen production, thereby reducing testosterone levels in the body to help slow prostate cancer growth. Some key points to consider when taking abiraterone include:
- Monitoring of liver function, potassium and phosphate levels, and blood pressure readings on a monthly basis is warranted during abiraterone therapy 1
- Symptom-directed assessment for cardiac disease also is warranted, particularly in patients with pre-existing cardiovascular disease 1
- Abiraterone can cause significant side effects, including fatigue, back or joint discomfort, peripheral edema, diarrhea, nausea, and constipation, among others 1
From the FDA Drug Label
DOSAGE AND ADMINISTRATION Metastatic castration-resistant prostate cancer: Abiraterone acetate tablets 1,000 mg orally once daily with prednisone 5 mg orally twice daily. Abiraterone acetate tablets must be taken on an empty stomach with water at least 1 hour before or 2 hours after a meal. Do not crush or chew tablets.
Abiraterone is taken orally once daily. The recommended dose is 1,000 mg and it should be taken with prednisone 5 mg twice daily. Key points to consider when taking abiraterone include:
- Taking the tablets on an empty stomach
- Taking the tablets with water
- Taking the tablets at least 1 hour before or 2 hours after a meal
- Not crushing or chewing the tablets 2
From the Research
Administration of Abiraterone
- Abiraterone acetate is typically administered orally at a dose of 1000 mg once daily 3.
- It is often given in combination with prednisone, a glucocorticoid, to mitigate the risk of mineralocorticoid excess 4, 5, 6.
- The recommended dose of prednisone is 5 mg twice daily 3 or 5 mg once daily 4, 5, 6.
Considerations for Administration
- Abiraterone acetate can be taken without glucocorticoids, but this approach requires close monitoring for mineralocorticoid toxicity 7.
- Patients with controlled blood pressure and normal potassium levels may be eligible for abiraterone acetate without steroids 7.
- However, some patients may still experience adverse events such as hypertension and hypokalemia, and may require initiation of prednisone therapy 7.
Clinical Trials and Studies
- Several clinical trials have investigated the efficacy and safety of abiraterone acetate in combination with prednisone for the treatment of metastatic castration-resistant prostate cancer 4, 5, 6.
- These studies have demonstrated significant improvements in overall survival and radiographic progression-free survival compared to standard care 4, 5, 6.