Ammonium chloride is mainly used clinically for those who have thick and sticky sputum that is not easy to cough up, and also for urinary tract infections when acidification of urine is required. The chemical stimulation of the mucous membrane, reflexively increase the volume of sputum, so that sputum is easy to discharge, and is conducive to the removal of sticky sputum that is not easy to cough up. After this product is absorbed, chloride ions enter the blood and extracellular fluid to acidify the urine. There is nausea and occasionally vomiting after taking this product. It should be used with caution in people with abnormal liver and kidney functions, and is contraindicated in people with severe damage to liver and kidney functions, especially hepatic coma, renal failure and uremia, and is contraindicated in patients with metabolic acidosis. Overdose and long-term use can cause acidosis and hypokalemia. The use of this product for pregnant and lactating women has not been clarified, and it should be used with caution in the elderly. The drug needs to be used under medical supervision.