Final answer:
Diuretics, specifically loop diuretics, can cause increased frequency of urination by inhibiting the reabsorption of sodium and chloride in the kidneys.
Step-by-step explanation:
The drug that causes increased frequency of urination is most likely a diuretic. Diuretics are medications that help the kidneys eliminate excess fluid from the body by increasing the production of urine. One type of diuretic, called a loop diuretic, works on the loop of Henle in the kidneys, inhibiting the reabsorption of sodium and chloride.