COVID-19 is a dangerous disease that has been treated with dangerous and ineffective drugs like chloroquine and hydroxychloroquine. Nonsteroidal anti-inflammatory agents may also be dangerous in the disease due to embolism formation. Safe and potentially effective alternative medicines are proposed.
Computed tomography shows peripheral distribution of lung damage with ground glass opacity and bilateral patchy shadowing . Macrophages invade into the lungs and become inflammatory dendritic cells . These cells contain cyclooxygenase-2 that makes prostaglandins that interact with prostaglandin receptors and transient receptor potential cation (TRP) channels to induce pain and inflammation . Inflammatory dendritic cells activate T cells, including Th2 and Th17 cells that produce cytokines and chemokines. Chemokines can attract neutrophils and more macrophages into the lungs. Neutrophils are probably involved in lung damage. High blood levels of neutrophils are associated with severe illness in COVID-19 . Neutrophils secrete leukotrienes, such as leukotriene B4  that activate TRP channels causing pain and inflammation . Monoterpenoids such as camphor, cineole and menthol inhibit TRP channels . Administration of small doses of monoterpenoids to COVID-19 patients may help with pain and inflammation in the lungs. Monoterpenoid preparations are available that can be applied inside the lower nostrils with cotton swabs. Evaporation of the monoterpenoids leads to inhalation into the lungs. Inhibition of inflammatory dendritic cell activity might also help with pain and inflammation in the lungs. Chloroquine and hydroxychloroquine are known to inhibit inflammatory dendritic cell activity . Echinacea preparations and Sambucus nigra flower preparations can also inhibit inflammatory dendritic cell activity . S. nigra might additionally increase tumor necrosis factor levels  and should be used only very early in disease progression to avoid cytokine release syndrome.
Embolism is an important feature of COVID-19 including prominent pulmonary embolism in 30% or more of patients . The use of nonsteroidal anti-inflammatory agents such as aspirin, ibuprofen, naproxen and acetaminophen should be discouraged in the disease since these drugs increase embolism formation and may increase the incidence of heart attacks, strokes and other coagulation events.