When to discontinue Flomax (tamsulosin) after passing a kidney stone?

From the Guidelines

Tamsulosin (Flomax) should be discontinued 24-48 hours after successfully passing a kidney stone, once urinary symptoms have resolved, as there is no benefit to continuing the medication long-term after stone passage unless prescribed for another condition like benign prostatic hyperplasia (BPH) 1. The decision to discontinue tamsulosin is based on the fact that the medication is used to facilitate stone passage by relaxing the smooth muscles in the urinary tract, particularly at the junction between the ureter and bladder, which helps reduce urinary obstruction and pain. Some key points to consider when discontinuing tamsulosin include:

• The standard dosage is usually 0.4 mg taken once daily 1.
• Common side effects include dizziness, headache, and retrograde ejaculation, which should resolve after discontinuation.
• If you experience persistent pain, fever, or difficulty urinating after stopping tamsulosin, contact your healthcare provider as these symptoms may indicate complications or remaining stone fragments. It's also important to note that the maximum time duration for which a trial of medical expulsive therapy (MET) is considered safe has not been clearly elucidated, but experimental data suggest that the interval of conservative therapy should not exceed six weeks from initial clinical presentation to avoid irreversible kidney injury 1. In terms of follow-up care, clinicians should offer repeat imaging prior to stone intervention if symptoms have changed, and a tailored approach should be utilized to limit radiation exposure 1. Overall, the discontinuation of tamsulosin after passing a kidney stone should be based on individual patient needs and symptoms, and patients should be counseled on the potential benefits and risks of continuing or discontinuing the medication.

From the Research

Discontinuing Flomax after Passing a Kidney Stone

• The decision to discontinue Flomax (tamsulosin) after passing a kidney stone should be based on the individual patient's condition and the size of the stone, as evidenced by studies 2, 3, 4.
• According to a study published in JAMA internal medicine 2, tamsulosin did not significantly increase the stone passage rate compared with placebo for symptomatic urinary stones smaller than 9 mm.
• However, another study published in The Journal of pharmacy technology 3 found that alpha-blockers, including tamsulosin, are beneficial for ureteral stones 5 to 10 mm without lithotripsy, and for renal or ureteral stones >10 mm post-lithotripsy.
• A systematic review and network meta-analysis published in International braz j urol 5 compared the efficacy of three commonly used alpha-blockers (tamsulosin, alfuzosin, and silodosin) as medical expulsive therapy for distal ureter stones, and found that silodosin had the highest efficacy, followed by alfuzosin and tamsulosin.
• A multicenter, randomized, double-blind, placebo-controlled trial published in European urology 4 found that tamsulosin significantly facilitated the passage of distal ureteral stones and relieved renal colic, especially for stones >5mm.

Factors to Consider

• Stone size: Tamsulosin may be more effective for larger stones (>5mm) 4.
• Stone location: Tamsulosin may be more effective for distal ureteral stones 4.
• Patient symptoms: Tamsulosin may help relieve renal colic and reduce the need for analgesics 4.
• Potential side effects: Tamsulosin may cause postural hypotension and retrograde ejaculation, especially silodosin 5.

Discontinuation Guidelines

• There is no specific guideline on when to discontinue Flomax after passing a kidney stone, but it is generally recommended to continue treatment for 28 days 2, 4.
• Patients should follow their doctor's instructions and attend follow-up appointments to monitor their condition and adjust treatment as needed.