Management Strategies for Nocturia

PURPOSE OF REVIEW

Nocturia is defined as awakening due to the desire to void during a period of intended sleep. The pathophysiology of nocturia is multifactorial and management remains a challenge. Herein, we provide an overview of the management strategies for nocturia and summarize the existing evidence for treatment of nocturia across the condition's broad etiologic categories: nocturnal polyuria, diminished bladder capacity, and global polyuria.

RECENT FINDINGS

Treatment should begin with behavioral modification. A high level of evidence supports the efficacy of desmopressin in the treatment of nocturnal polyuria. Data supporting the efficacy of α-blockers, antimuscarinics, and surgical bladder outlet procedures in the treatment of nocturia remains limited. Treatment options for nocturia are determined by underlying mechanism. Desmopressin is effective in treating nocturnal polyuria. Surgical intervention, α-blockers, and antimuscarinics may improve nocturia when associated with lower urinary tract symptoms or overactive bladder in the setting of diminished bladder capacity.

Amitriptyline or Not, That Is the Question: Pharmacogenetic Testing of CYP2D6 and CYP2C19 Identifies Patients with Low or High Risk for Side Effects in Amitriptyline Therapy

Background: Amitriptyline has been replaced in many countries by alternative and more expensive drugs based on claims of improved tolerability and toxicity and despite slightly reduced efficacy. Preliminary studies indicate that adverse effects could be linked to polymorphisms of drug-metabolizing enzymes, but information on their clinical impact remains scanty and includes mainly case reports. We conducted a prospective blinded two-center study seeking correlations between CYP2C19 and CYP2D6 genotypes, drug concentrations, adverse events, and therapy response.

Methods: Fifty Caucasian inpatients with at least medium-grade depressive disorder received amitriptyline at a fixed dose of 75 mg twice a day. Blood samples for concentration monitoring of amitriptyline and nortriptyline were taken weekly until discharge along with evaluations of depression (Hamilton Depression Scale and Clinical Global Impression Scale) and side effect (Dosage Record and Treatment Emergent Symptoms Scale; DOTES) scores.

Results: In a ROC analysis, nortriptyline but not amitriptyline concentrations correlated with side effects (DOTES sum score ≥5; area under the curve, 0.733; P = 0.008). Carriers of two functional CYP2D6 alleles had a significantly lower risk of side effects than carriers of only one functional allele (12.1% vs 76.5%; P = 0.00001). The lowest risk was observed for carriers of two functional CYP2D6 alleles combined with only one functional CYP2C19 allele [0 of 13 (0%) vs 9 of 11 (81.8%) for the high-risk group; P = 0.00004]. We found no correlations between drug concentrations or genotypes and therapeutic response.

Conclusions: Combined pharmacogenetic testing for CYP2D6 and CYP2C19 identifies patients with low risk for side effects in amitriptyline therapy and could possibly be used to individualize antidepressive regimens and reduce treatment cost. Identification of genotypes associated with slightly reduced intermediate metabolism may be more important than currently anticipated. It could also be the key to demonstrating cost-effectiveness for CYP2D6 genotyping in critical dose drugs.