Final answer:
Antispasmodics are the type of medication that alleviate urine leakage from an overactive bladder by relaxing the bladder's detrusor muscle and reducing involuntary contractions.
Step-by-step explanation:
The medication that relieves 'leaking' of urine resulting from an overactive bladder is antispasmodics (3). Antispasmodics are used to relax the detrusor muscle within the wall of the bladder, thereby reducing the occurrence of the involuntary contractions that lead to urge incontinence, which is characterized by the sudden and overwhelming need to urinate. Other treatments mentioned, such as diuretics and antibiotics, serve different purposes. Diuretics increase urine production and are typically used to treat conditions such as hypertension and fluid retention, whereas antibiotics are used to treat bacterial infections like cystitis.
Loop diuretics, which are sometimes used to treat hypertension, work by inhibiting the reabsorption of sodium (Na+) and chloride (Cl-) ions in the ascending limb of the loop of Henle in the kidneys, leading to increased urination as a side effect. This is not the desired treatment for overactive bladder as it could exacerbate symptoms by increasing urine volume. Instead, antispasmodics are specifically targeted to mitigate urge incontinence by preventing the overactive bladder from emptying suddenly and unexpectedly.