From the Guidelines
Yes, 20mg of Endep (amitriptyline) can potentially cause an elevated post-void residual (PVR) volume of 111ml. Amitriptyline is a tricyclic antidepressant that has significant anticholinergic properties, which can affect bladder function by inhibiting detrusor muscle contraction and potentially increasing urethral resistance. This medication commonly causes urinary retention as a side effect, even at lower doses like 20mg. A PVR volume of 111ml is considered mildly elevated (normal is typically less than 50ml), and this level of retention could be consistent with amitriptyline's anticholinergic effects. Some key points to consider include:
- The anticholinergic effects of amitriptyline can lead to urinary retention, as noted in various studies, although specific data on 20mg dosing may be limited 1.
- Clinicians should be aware of the potential for elevated PVR volumes when prescribing medications with anticholinergic properties, such as amitriptyline, especially in patients with pre-existing lower urinary tract symptoms (LUTS) or benign prostatic hyperplasia (BPH) 1.
- Monitoring and discussion of urinary symptoms are crucial when patients are taking medications that can affect bladder function, as adjustments in medication or additional treatments may be necessary to manage these side effects.
- The dose-dependent nature of amitriptyline's urinary retention effect suggests that reducing the dose could potentially mitigate this side effect if the medication is otherwise beneficial for the patient's condition. Given the potential for amitriptyline to cause urinary retention, it is essential for patients experiencing urinary symptoms while taking this medication to discuss their symptoms with their healthcare provider. The provider may consider adjusting the medication, recommending timed voiding strategies, or potentially prescribing medications to improve bladder emptying if necessary, based on the most recent guidelines and evidence available 1.
From the FDA Drug Label
Anticholinergic: ... urinary retention, dilatation of the urinary tract; ... The FDA drug label mentions urinary retention as a possible adverse reaction, which can be associated with an elevated Post Void Residual (PVR) volume.
- The label does not provide a specific volume, such as 111ml, but it does suggest that amitriptyline can cause urinary retention.
- Given that 20mg of Endep (Amitriptyline) can cause anticholinergic effects, including urinary retention, it is possible that it could contribute to an elevated PVR volume of 111ml 2.
- However, without more specific information, it is difficult to determine the exact relationship between the 20mg dose and the PVR volume of 111ml.
- Urinary retention is a known side effect of amitriptyline, and it can lead to elevated PVR volumes.
From the Research
Post Void Residual (PVR) Volume and Endep (Amitriptyline)
- The question of whether 20mg Endep (Amitriptyline) can cause an elevated Post Void Residual (PVR) volume of 111ml is complex and requires an understanding of both the medication's effects and the condition of elevated PVR.
- Elevated PVR volumes are often associated with urinary retention, which can be caused by various factors including medications, urinary tract issues, or neurological problems 3.
- Amitriptyline, an antidepressant, is known to have anticholinergic side effects, which can potentially lead to urinary retention by relaxing the detrusor muscle of the bladder, thus reducing the ability to void urine completely 4.
Relationship Between Amitriptyline and Urinary Retention
- While there is evidence suggesting that anticholinergic medications can contribute to urinary retention, the specific effect of 20mg Amitriptyline on PVR volume is not directly addressed in the provided studies.
- However, it is plausible that Amitriptyline could contribute to an elevated PVR due to its anticholinergic properties, which can affect bladder function and potentially lead to incomplete emptying of the bladder 3, 4.
Assessment and Management of Elevated PVR
- The management of elevated PVR often involves assessing the underlying cause, which could include medication side effects, and may involve interventions such as clean intermittent catheterization or adjustments to medication regimens 5, 4.
- In cases where medication is suspected to contribute to urinary retention, alternatives with fewer anticholinergic side effects may be considered, or the dosage may be adjusted under medical supervision.