Abiraterone acetate is the generic name for the chemotherapy drug Zytiga®. In some cases, healthcare professionals may use the brand name Zytiga® to refer to the generic name of the drug abiraterone acetate.
Abiraterone is used in combination with prednisone to treat a certain type of prostate cancer that has spread to other parts of the body. Abiraterone is in a class of medications called androgen biosynthesis inhibitors. It works by decreasing the amount of certain hormones in the body.
The results of two large clinical studies may change the way some men with metastatic prostate cancer are treated. Both studies showed that the addition of the hormone-blocking drug abiraterone (Zytiga®) to conventional androgen deprivation therapy allowed men with hormone-sensitive metastatic prostate cancer to live longer than if they were treated with androgen deprivation therapy alone.
How abiraterone acetate works
Hormones are chemicals produced by the body’s glands that enter the bloodstream and cause effects in other tissues. The use of hormone therapy to treat cancer is based on the observation that receptors for specific hormones necessary for cell growth are found on the surface of some tumor cells. Hormone therapy can work by stopping the production of a certain hormone, blocking the hormone receptors, or replacing the active hormone with chemically similar agents that cannot be used by the tumor cell. The different types of hormone therapy are classified according to their function and / or the type of hormone they work on.
The growth of prostate cancer is stimulated by male hormones (androgens / testosterone). Reducing the production of these hormones is essential to help men fight prostate cancer. Androgens are produced mainly in the testes and adrenal glands. However, in men with advanced prostate cancer, metastatic tumors have the ability to produce their own testosterone. Prostate cancer usually responds to treatment that lowers androgen levels. Many androgen deprivation therapies decrease androgen production in the testes but do not affect androgen production in other parts of the body, such as the adrenal glands or the tumor.
Abiraterone acetate works differently from other androgen deprivation therapies. Abiraterone acetate interferes with an enzyme that is expressed in testicular, adrenal, and prostate tumor tissues and is required as part of the body’s androgen production process. As a result of this interference, the amount of androgens that are produced decreases. Abiraterone acetate blocks androgen production from all sources: the testes, the adrenal glands, and the tumor itself.
How should this medicine be used?
Abiraterone comes as a tablet to take by mouth on an empty stomach with water, 1 hour before or 2 hours after meals. It is usually taken once or twice a day. Take abiraterone at around the same time every day. Carefully follow the directions on your prescription label and ask your doctor or pharmacist to explain any parts you do not understand. Take abiraterone exactly as directed. Do not take more or less of the medicine, or take it more often than your doctor tells you.
Swallow the tablets whole with water; do not split, chew, or crush them.
Keep taking abiraterone even if you feel fine. Do not stop taking abiraterone or prednisone without first talking to your doctor.
Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.
What special precautions should I follow?
Before taking abiraterone,
- Tell your doctor and pharmacist if you are allergic to abiraterone, any other medications, or any of the ingredients in abiraterone tablets. Ask your pharmacist for a list of the ingredients.
- Tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: dextromethorphan, some seizure medications such as carbamazepine (Carbatrol, Epitol, Tegretol), phenobarbital, and phenytoin (Dilantin, Phenytek), ketoconazole; nefazodone; Pioglitazone (Actos); rifabutin (Mycobutin); rifampicin (Rifadin, in Rifamate, in Rifater, Rimactane); rifapentine (Priftin); and thioridazine. Your doctor may need to change the doses of your medications or monitor you closely for side effects. Many other medications could also interact with abiraterone,so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
- Tell your doctor if you have an infection, a low potassium level in your blood, or if you are under unusual stress, have had a recent heart attack, or if you have or have ever had pituitary gland problems or adrenal problems. heart failure, irregular heart rhythm, even QT prolongation (an irregular heart rhythm that can lead to fainting, loss of consciousness, seizures, or sudden death), high blood pressure, or heart or liver disease.
- You should know that abiraterone is only for use in men. Women should not take this medicine, especially if they are or may become pregnant or are breastfeeding. If taken by pregnant women, abiraterone can harm the fetus. Women who are, could become, or could be pregnant should not handle abiraterone tablets without protective gloves. If a pregnant woman takes or touches abiraterone tablets, she should immediately call her doctor.
- Men who have a female partner and are taking abiraterone must use effective contraception during treatment and for 3 weeks after the final dose. Talk to your doctor about the types of birth control that are right for you.
- You should know that this medicine can decrease fertility in men. Talk to your doctor about the risks of taking abiraterone.
Side effects it could cause.
Abiraterone can cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- joint swelling or pain
- groin pain
- hot flashes (a sudden wave of mild or intense body heat)
- diarrhea,
- acidity,
- cough,
- Difficulty falling asleep or staying asleep.
Some Side Effects Can Be Serious. If you experience any of these symptoms, call your doctor immediately:
- dizziness
- feeling faint or dizzy
- headache.
- confusion,
- fast or irregular heartbeat
- muscle weakness or aches
- leg pain,
- swelling of the hands, feet, ankles, or lower legs
- rash,
- unusual bleeding or bruising
- exhausted,
- lack of energy,
- nausea,
- vomiting
- loss of appetite
- pain in the upper right part of the stomach
- jaundice of the skin or eyes
- flu-like symptoms, eg. eg, fever;
- blood in the urine,
- frequent, painful, or difficult urination
- fracture of a bone.
Abiraterone can cause other side effects. Call your doctor if you have any unusual problems while taking this medicine.
Mechanism of action Abiraterone
Selective inhibitor of the enzyme 17 alpha-hydroxylase / C17,20-lyase (CYP17). CYP17 catalyzes the conversion of pregnenolone and progesterone to the precursors of testosterone, DHEA and androstenedione, respectively, by 17 alpha-hydroxylation and cleavage of the C17,20 bond. CYP17 inhibition also leads to increased mineralocorticoid production by the adrenal glands.
Pregnancy
There are no data on the use of abiraterone in pregnant women, so it should not be used in women of childbearing potential. It is unknown whether abiraterone or its metabolites are present in semen. If the patient has sexual intercourse with a pregnant woman, he must use a condom. If the patient has sexual intercourse with a woman of childbearing potential, he must use a condom in conjunction with another effective contraceptive method. Studies in animals have shown reproductive toxicity. Abiraterone should not be used in women. Abiraterone Acetate is contraindicated in pregnant or potentially pregnant women.
Lactation
It is not indicated in women. It is unknown whether abiraterone acetate or its metabolites are excreted in human milk.
Effects on the ability to drive
The influence on the ability to drive and use machines is zero or negligible.
Trademarks
Zytiga®