From the Guidelines
Phenobarbital is not directly associated with causing urinary retention, according to the provided evidence. The study 1 focuses on the extracorporeal treatment for barbiturate poisoning and discusses various aspects of barbiturate toxicity, including cardiovascular effects, serum concentration, and treatment options. However, it does not mention urinary retention as a potential side effect of phenobarbital.
Some key points to consider when evaluating the potential side effects of phenobarbital include:
- The therapeutic range for anticonvulsant activity of phenobarbital is 10-25 mg/L, as stated in the study 1.
- Serum concentrations above 50 mg/L may induce coma and concentrations above 80 mg/L may be fatal, highlighting the importance of monitoring serum levels when taking this medication.
- Optimal supportive care is mandatory in all cases of barbiturate poisoning, and interventions to enhance elimination should provide substantially greater elimination than endogenous mechanisms alone to be considered effective.
It is essential to note that while the provided evidence does not support a direct link between phenobarbital and urinary retention, patients taking this medication should still be aware of potential side effects and report any concerns to their healthcare provider. Other common side effects of phenobarbital, such as drowsiness, dizziness, and coordination problems, should also be monitored. If urinary retention or other urinary issues occur, healthcare providers may need to adjust the dosage or implement strategies to manage these side effects.
From the FDA Drug Label
Studies in laboratory animals have shown that barbiturates cause reduction in the tone and contractility of the uterus, ureters and urinary bladder. However, concentrations of the drugs required to produce this effect in humans are not reached with sedative-hypnotic doses
The FDA drug label suggests that phenobarbital may cause a reduction in the tone and contractility of the urinary bladder in laboratory animals, but the concentrations required to produce this effect are not typically reached with sedative-hypnotic doses in humans. Urinary retention is not directly mentioned as a potential effect of phenobarbital. However, based on the information provided, it is possible that high doses of phenobarbital could potentially cause urinary retention due to the reduction in tone and contractility of the urinary bladder.
- Key points:
- Reduction in tone and contractility of the urinary bladder in laboratory animals
- Concentrations required to produce this effect are not typically reached with sedative-hypnotic doses in humans
- Urinary retention is not directly mentioned as a potential effect of phenobarbital
- Clinical decision: Due to the lack of direct evidence, it is unclear whether phenobarbital can cause urinary retention in humans. However, as a precautionary measure, patients taking phenobarbital should be monitored for any signs of urinary retention. 2 2
From the Research
Phenobarbital and Urinary Retention
- There is no direct evidence in the provided studies that phenobarbital causes urinary retention 3, 4, 5, 6, 7.
- However, it is known that certain medications with anticholinergic activity, opioids, and anaesthetics can cause urinary retention 3.
- Phenobarbital is a barbiturate with sedative and anticonvulsant properties, but its effects on the urinary system are not well-studied in the context of urinary retention 6.
- The studies provided focus on the incidence, management, and prevention of drug-induced urinary retention, as well as the evaluation and initial management of urinary retention in adults 3, 4, 5.
- Another study discusses the pharmacological treatment of benign prostatic hyperplasia, which can cause urinary retention, but does not mention phenobarbital as a potential cause 7.
- Overall, there is limited information available on the potential relationship between phenobarbital and urinary retention, and further research would be needed to determine if there is a link between the two 6.