What can replace Novahistine DMX cough syrup? Nothing helps now since they discontinued this syrup years ago. Taking them individually also doesn't work. DMX helped within 5 minutes. ## When you took them individually, were they in tablet/capsule form, or liquids? Since a cough syrup is liquid, it is normal for it to work fairly fast, but tablets, and capsules tend to take a bit longer to take affect. Novahistine DMX contained Dextromethorphan, Guaifenesin, and Pseudoephedrine, and this combination is available in a couple other products, as well, such as Robitussin Cough & Cold D, and Maxifed DMX. Your pharmacist should be able to help you find an equivalent. Has your doctor suggested any solutions? However, some combinations over the counter may have changed their active ingre...