Nocturia in the elderly: A wake-up call
ABSTRACTNocturia is a condition that health providers must seek out and address in older adults. Since it adversely affects quality of life and carries a risk of morbidity and of death (often because of falling), this symptom must be elicited during the physician-patient encounter. Understanding its underlying causes, risk factors, and consequences is essential in formulating the most suitable management strategy. Drug and nondrug treatments target the individual disorders that contribute to nocturia.
KEY POINTS
- Nocturia is multifactorial and is caused by factors that increase urine production and others that decrease the bladder’s ability to hold urine.
- The first priority in treating nocturia is to identify and treat concomitant conditions that may be contributing to it, such as diabetes mellitus, diabetes insipidus, urinary tract infections, hypercalcemia, and hypokalemia.
- Nonpharmacologic measures can help, but by themselves usually do not solve the problem.
- Drug therapies for nocturia include desmopressin (DDAVP), antimuscarinic agents, alpha-blockers, and 5-alpha reductase inhibitors.
WHAT ARE THE TREATMENT OPTIONS?
Therapy must be directed at the primary cause, addressing any underlying conditions that can contribute to nocturia. Examples39:
- Tight control of blood sugar for patients with diabetes mellitus
- Treatment of diabetes insipidus
- Referral for patients with primary polydipsia
- Management of hypercalcemia and hypokalemia
- A survey of medications
- Treatment of infections.
Nonpharmacologic measures
Tailored behavioral therapy can also be instituted, but the patient needs to have realistic expectations, as these measures are rarely effective alone.
Avoiding nighttime fluid intake, including alcohol and caffeine, has shown promise.
Wearing compression stockings and elevating the legs in the afternoon decrease the retention of fluid that otherwise would return to the circulation at night.
Identifying and eliminating nighttime influences that disturb sleep has variable efficacy. The use of continuous positive airway pressure helps to treat sleep apnea. Moderate exercise, reducing nonsleep time spent in bed,42 and sleeping in a warm bed43 to decrease cold diuresis have also been shown to improve sleep quality.44 Patients with nocturia may have a disrupted circadian rhythm, and phototherapy may help resynchronize the diurnal rhythm and melatonin secretion.
Pharmacotherapy
Pharmacotherapy of nocturia includes desmopressin (DDAVP) to manage nocturnal polyuria and antimuscarinic agents to manage the patient’s decreased ability to store urine. Alpha-blockers such as tamsulosin (Flomax) and 5-alpha-reductase inhibitors such as finasteride (Proscar) are used for men with benign prostatic hyperplasia. Novel and second-line therapies include diuretics such as furosemide (Lasix), cyclooxygenase-2 inhibitors, as well as botulinum toxin injected directly into the detrusor muscle for overactive bladder.45
Desmopressin in a low oral dose (0.1–0.4 mg) at bedtime can be initiated and the response assessed. Patients with nocturnal polyuria and disorders of the vasopressin system have been found to be more sensitive to desmopressin therapy.46 Fluid retention and hyponatremia can complicate therapy, and desmopressin must be avoided in patients with liver cirrhosis, renal failure, or congestive heart failure.47
Antimuscarinic agents are effective for patients who have lower urinary tract symptoms and for those with a diminished ability to store urine. They act by decreasing both voluntary and involuntary bladder contractions by blocking muscarinic receptors on the detrusor muscle. This reduces the bladder’s ability to contract and the urge to urinate, thereby increasing bladder capacity.48 These agents include oxybutynin (Ditropan), tolterodine (Detrol), solifenacin (Vesicare), and propiverine (not available in the United States).
Diuretics are being used as second-line agents or for patients who cannot tolerate desmopressin.49 Hydrochlorothiazide is taken 8 hours before bedtime to prevent water accumulation before the early sleeping hours.50 Furosemide has also led to a reduction in the mean number of nocturnal voids.51 The effect of these drugs on nocturia are especially beneficial to patients with concomitant hypertension or cardiovascular disease.
Cyclo-oxygenase-2 inhibitors such as celecoxib (Celebrex)52 and other nonsteroidal anti-inflammatory drugs such as diclofenac (Voltaren, others)53 and loxoprofen (not available in the United States)54 have been shown to decrease urine production, detrusor muscle tone, and inflammation, especially in men with benign prostatic hyperplasia.
Botulinum toxin has been used, usually in patients refractory to first-line treatment.44
Table 4 summarizes the treatment strategies for nocturia.
CASES REVISITED
The first patient described above has nocturia caused by several concomitant diseases, ie, hypertension, diabetes, benign prostatic hyperplasia, and obstructive sleep apnea. In addition to controlling his blood pressure and blood sugar, his primary care provider referred him to a pulmonologist, who confirmed obstructive sleep apnea with polysomnography and prescribed nightly use of a continuous positive airway pressure apparatus. A few weeks later, the patient’s nocturia had improved significantly, and his level of fatigue had decreased.
Apart from hypertension, the second patient’s nocturia was mostly attributed to her existing urinary incontinence. Recognizing that her current antihypertensive regimen may worsen nocturia, her family physician changed it to enalapril (Vasotec) and doxazosin (Cardura) and counseled her to restrict her fluid intake 2 hours before bedtime. She was also referred to a gynecologist, who found a moderate degree of cystocele and treated her with a collagen injection. Her nocturia improved significantly.
