No it cannot. I had bronchitis in the beginning of my pregnancy that lasted a month. Vapor cream, Robitussin, and oral steroids were my best friends. I'm surprised they have prescribed you anything if you are sick.
Yeah I've been coughing and congested pretty much this whole pregnancy, mostly asthma-related with a not-fun upper respiratory infection thrown in. I feel pretty cruddy, but the baby seems to be fine.
Cough drops are okay, Vicks also helps. I also do a couple of cups of peppermint tea with honey per day. Honey is a natural cough syrup, so you can put a spoonful in your mouth and let it melt before you swallow it. I've managed to get through without over-the-counter meds. I did have to take antibiotics for the upper respiratory infection because we were worried about pneumonia, but again, the baby is fine.