Smoking marijuana may be tied to cough, sputum production

(HealthDay)—Smoking marijuana seems to be associated with increased risk of cough, sputum production, and wheezing, according to a review published online July 3 in the Annals of Internal Medicine.

Mehrnaz Ghasemiesfe, M.D., from the University of California in San Francisco, and colleagues reviewed data from 22 studies to examine the correlation between marijuana use and respiratory symptoms, pulmonary function, and obstructive lung disease. The authors included observational and interventional studies that reported pulmonary outcomes of adolescents and adults who used marijuana.

The researchers found that in a pooled analysis of two prospective studies, marijuana use was correlated with elevated risk for cough and sputum production (risk ratios, 2.04 and 3.84, respectively). In a pooled analysis of cross-sectional studies (one with low and three with moderate risk of bias), marijuana use was correlated with cough, sputum production, wheezing, and dyspnea (risk ratios, 4.37, 3.4, 2.83, and 1.56, respectively). The data on pulmonary function and obstructive lung disease were insufficient.

"Low-strength evidence suggests that smoking marijuana is associated with cough, sputum production, and wheezing," the authors write. "Evidence on the association between marijuana use and obstructive lung disease and pulmonary function is insufficient."