Compared to other chemicals available to 18th century regular physicians, opium was a benign alternative to the arsenics, mercuries, or emetics, and it was remarkably successful in alleviating a wide range of ailments. Due to the constipation often produced by the consumption of opium, it was one of the most effective treatments for cholera, dysentery, and diarrhea. As a cough suppressant, opium was used to treat bronchitis, tuberculosis, and other respiratory illnesses. Opium was additionally prescribed for rheumatism and insomnia. Medical textbooks even recommended its use by people in good health, to "optimize the internal equilibrium of the human body".