Why are combination pills not commonly prescribed?
The combination drugs such as Tedral and Marax commonly contain theophylline, ephedrine, and some form of sedative such as phenobarbital. These combination pills are no longer commonly prescribed because the amount of theophylline in the pill cannot be varied with respect to the other drugs. Since there is great variation in the rate at which an individual metabolizes theophylline, it is now considered better to take theophylline separately, for better adjustment of theophylline levels. In fact, Tedral is no longer manufactured by Parke-Davis in the U.S. Also, ephedrine is no longer considered the bronchodilator of choice. From Drs. Haas, _The Essential Asthma Book_, “ephedrine initiates the release of catecholamines — including adrenaline — that are already stored in the body. This is its biggest drawback. Its effects depend on the availability of catecholamine in the body at the time it is given, and these concentrations vary.” Since much better bronchodilators are now available, e
