1 Spread of the cancer to other parts of the body: Pain caused by cancer itself is more common in people who have metastatic (or advanced) disease, in which the breast cancer spreads to other parts of the body.
Toxicological Effects: 1  Acute toxicity: Atrazine is slightly to moderately toxic to humans and other animals. 2  Chronic toxicity: Some 40% of rats receiving oral doses of 20 mg/kg/day for 6 months died with signs of respiratory distress and paralysis of the limbs.
In addition, they prevent histamine from binding and stimulating the cells. Hydroxyzine itself has no histamine-like activity. After ingestion, it is converted to its active form. The active form of hydroxyzine is a drug called cetirizine (Zyrtec). Although, both hydroxyzine and cetirizine act as antihistamines, hydroxyzine causes more sedation than cetirizine. The FDA approved hydroxyzine in 1956.