Acute sinusitis; Chronic sinusitis 

Cysteine; L-Cysteine; N-acetylcysteine; NAC 

Sinusitis is inflammation, either bacterial, viral, allergic or autoimmune, of the paranasal sinuses.

A drug usually used to reduce the thickness of mucus and ease its removal. It is also used to reverse the toxicity of high doses of acetaminophen. Also called N-acetyl-L-cysteine.