My 91 yr. old mother is just getting over the most severe cold of her life! Her words, not mine, but it is true. She had trouble getting into her doctor s office, and was very much against going to a Redi-Care type service. She was very congested, with a bad cough. This cold lasted close to 3 wks. While keeping a watch on her, I got her a cough syrup containing Guiafenesin, which she took for 10-14 days, being careful not to over use. Her cold is almost completely over, but is now showing swelling in her calves and lower legs. Could this be a side effect? Thank you.