Different types of overactive bladder medications have been used for many years to treat a condition of abnormal bladder contractions known as overactive bladder (OAB). The most common types of OAB medications include anticholinergics, but estrogen, tricyclic antidepressants, and desmopressin are also used. Botulinum toxin type A is a potential new addition to the arsenal of overactive bladder medications that may also prove helpful. One main side effect of most of these medications is dry mouth; each drug also has its own side effects.
Anticholinergics block the neurotransmitter acetylcholine from delivering messages to the bladder that trigger abnormal contractions. These abnormal contractions create the urge to urinate even if the bladder is not full. Oxybutynin, tolterodine, darifenacin, solifenacin, trospium, and fesoterodine are generic anticholinergics prescribed for this condition and are usually taken several times a day. Many of the drugs have an extended-release form with once-a-day dosing. Oxybutynin is also available in a skin patch or cream which delivers the drug continuously.
Side effects of anticholinergics include dry mouth. Less often, those using these overactive bladder medications may experience constipation, heartburn, blurred vision, confusion, impaired memory, rapid heartbeat, or urinary retention. The patch version of oxybutynin sometimes causes skin irritation which can be resolved by putting the patch in a different location each time it is changed.
Topical estrogen cream is sometimes prescribed to postmenopausal women with OAB. Anecdotal evidence indicates that this medication may be helpful as a treatment for this condition, but there is little scientific evidence to support this. No side effects have been reported. Estrogen cream is usually prescribed along with other overactive bladder medications. It is important to note that the topical estrogen cream is different than hormone replacement therapy or oral estrogen replacement and may actually make OAB worse.
Tricyclic antidepressants may also be used as overactive bladder medications. They work by relaxing the bladder muscle itself and, at the same time, cause the bladder neck to contract. Drowsiness is the main side effect. Other possible side effects include irregular heart beat, dizziness, blurry vision, dry mouth, constipation, and unwanted interactions with other medications.
At night the body produces anti-diuretic hormone (ADH) which decreases urine production. Desmopressin, a synthetic form of ADH, may effectively treat nighttime OAB. Possible side effects include water retention and sodium deficiency. In rare cases, this can lead to seizures, brain swelling, and death.
Botulinum toxin type A, also known as Botox, may be effective at treating symptoms that have not responded to other overactive bladder medications. One injection into the bladder muscle blocks acetylcholine and paralyzes the bladder. It may give up to nine months of relief. Further studies must be conducted to validate its use with OAB. The drug has not been approved for this use by the U.S. Food and Drug Administration (FDA).