Final answer:
Phenazopyridine is effective for cystitis when it alleviates bladder pain, its primary use. Increased urination can be a side effect of loop diuretics, which inhibit reabsorption of Na+ and Cl- in the kidney.
Step-by-step explanation:
Phenazopyridine is prescribed to a client with cystitis. The nurse evaluates that the medication is effective based on the alleviation of bladder pain. Phenazopyridine is an analgesic that provides pain relief in the urinary tract, making it particularly useful in alleviating the discomfort associated with cystitis. This condition is often caused by a bacterial infection of the bladder and can lead to symptoms such as dysuria, pyuria, and hematuria. Treatment typically involves antibiotics, but pain medications like phenazopyridine can help manage symptoms. As for the question regarding a drug with a side effect that increases the frequency of urination, a possible cause could be that the drug is most likely a loop diuretic used to treat hypertension. Loop diuretics work by inhibiting the reabsorption of Na+ and Cl- ions in the ascending limb of the loop of Henle, leading to increased urination due to the excretion of these ions and associated water. This increased urination is a side effect of the drug's action on kidney function.