Deriphyllin can be used in pregnancy for short term. But But Asthma should not be treated with that drug.. inhalers are far better, lesser side effects, non addicting, safest in pregnancy, less dose needed, and many more reasons. Consult a chest physician and shift to only inhalers and no tablets if you have asthma. Just for information, asthma gets worse in one third, better in one third and remains same in one third during pregnancy.