One cause at least of the beneficial action of pilocarpin is the power of arousing very greatly increased physiological activity.
The apparent inertness, or the very limited effect, in many cases of medicines, as for example iodide of potash and mercury, may be due to the inability to arouse this increased physiological activity. As soon, however, as a medicine is added which can do this, then immediate good results follow. This further shows why pilocarpin in order to get its best results should always be used associated with other medicines suitable to the disease, for then it shows in the most marked manner its great value, its true position among medicines.
A look at the past . . .. Arch Ophthalmol. 1998;116(12):1700. doi:10.1001/archopht.116.12.1700