<unk> , also known as para-aminosalicylic<unk>  (PAS) and sold under the brand name Paser among others, is an antibiotic primarily used to treat tuberculosis. Specifically it is used to treat active drug resistant tuberculosis together with other antituberculosis medications. It has also been used as a second line agent to sulfasalazine in people with inflammatory bowel disease such as ulcerative colitis and Crohn's disease. It is typically taken by mouth. Common side effects include nausea, abdominal pain, and diarrhea. Other side effects may include liver inflammation and allergic reactions. It is not recommended in people with end stage kidney disease. While there does not appear to be harm with use during pregnancy it has not been well studied in this population.<unk>  is believed to work by blocking the ability of bacteria to make folic<unk> .<unk>  was first made in 1902, and came into medical use in 1943. It is on the World Health Organization's List of Essential Medicines. , a course of treatment for tuberculosis costs about US$2,700.
4-Aminosalicylic acid
Quinine
Salicylic acid
Trenbolone hexahydrobenzylcarbonate
Pyrimethamine
Pentamidine
Artemisinin
Phenpromethamine