Are lozol and zaroxolyn (metolazone) prescribed a lot?

Not unusually. Both are relatively frequently used medications for diuresis. However, they belong to the mild diuretics category unless combined with other diuretics. Zaroxylyn in particular has the claim of fame of being effective if added to Furosemide in patients with resistant diuresis with chf. By itself, it is used infrequently and other cheaper thiazides (same family) do the same effect e.g. Hctz (hydrochlorothiazide).