Which diuretic causes increase in creatinine? Are you sure you mean diuretics or are you talking about ACE inhibitors which increase serum creatinine by 30% the first 3-5 days which then stabilizes after 2-3 weeks.
The only connection I know of with increased creatinine due to diuretic use is in nephrogeneic diabetes insipidus, for some reason thiazides have a paradoxic antidiuretic effect on them. That's why the paradox is an extreme diuresis is treated with a diuretic. Thiazide diuretics will decrease distal convoluted tubule reabsorption of sodium and water, thereby causing diuresis. This decreases plasma volume, thus lowering GFR and enhancing the absorption of sodium and water in the proximal nephron. Less fluid reaches the distal nephron, so overall fluid conservation is obtained.
Is that what you were referring to? If not, sorry I don't know but I would appreciate if someone would answer this.