Anastrozole tablets have gastric side effects such as anorexia, nausea, vomiting and diarrhea. The drug has gastrointestinal side effects such as anorexia, nausea, vomiting, diarrhea and other gastrointestinal dysfunctions as it is clearly stated in the instructions. The drug is a potent, selective nonsteroidal aromatase inhibitor. It can inhibit the conversion of androstenedione produced in the adrenal glands of postmenopausal patients into estrone, thus significantly reducing plasma estrogen levels and producing inhibition of breast tumor growth. Clinically, the drug is used to treat advanced breast cancer in postmenopausal women that remains uncontrolled by tamoxifen and other anti-estrogen therapies. In addition to side effects on the stomach, adverse reactions such as fatigue, flushing of the skin, vaginal dryness, overproduction of oil in the hair, and rashes may occur during use of the drug. The drug is contraindicated in premenopausal women, pregnant or breastfeeding women, patients with severe kidney damage, and patients with moderate to severe liver damage. Athletes should be cautious; driving and operating machinery should be avoided while using the drug. If medication is needed, it should be used under the guidance of a physician, and should not be used on its own to avoid adverse reactions.