How long should a patient with BPH stop taking Xatral X (alfuzosin) before starting tamsulosin for a ureteral stone?

Switching from Xatral X (Alfuzosin) to Tamsulosin for Ureteral Stone

Direct Answer

You do not need to stop Xatral X (alfuzosin) before starting tamsulosin—you can switch directly without any washout period. Both medications are alpha-1 blockers with similar mechanisms of action and short half-lives, making immediate transition safe 1, 2, 3.

Rationale for Direct Switching

Pharmacologic Considerations

• Both alfuzosin and tamsulosin are alpha-1 adrenergic blockers that work by relaxing smooth muscle in the ureter and bladder outlet 2, 3
• Alfuzosin has a half-life of approximately 10 hours, meaning it is largely eliminated from the body within 24-48 hours 1
• Since both drugs act on the same receptors with similar mechanisms, there is no pharmacologic reason to have a drug-free interval between them 2, 3

Clinical Practice Guidelines

• Guidelines for acute urinary retention recommend starting alpha blockers immediately at the time of catheter insertion, without any washout period from prior alpha blocker therapy 1, 2, 3
• The American Urological Association recommends prescribing non-titratable alpha blockers (tamsulosin or alfuzosin) for medical expulsive therapy without specifying any washout period when switching between agents 1, 2

Practical Switching Protocol

Recommended Approach

• Stop alfuzosin and start tamsulosin 0.4 mg once daily the next day 2, 3
• For ureteral stones, tamsulosin should be continued throughout the stone passage period, typically up to 28 days 4, 5, 6
• No overlap or gap period is necessary between the two medications 1, 2

Efficacy for Ureteral Stones

• Both alfuzosin and tamsulosin demonstrate similar efficacy for medical expulsive therapy of distal ureteral stones 7, 8
• For stones 5-10 mm, tamsulosin increases stone passage rates from 61% (placebo) to 83.3%, with a number needed to treat of 4.5 6
• The European Association of Urology guidelines recommend medical expulsive therapy with tamsulosin for distal ureteral stones, particularly those 5-10 mm in size 4

Important Clinical Considerations

Safety Monitoring

• Both medications can cause orthostatic hypotension, though tamsulosin has greater selectivity for prostatic alpha-1A receptors and may have lower cardiovascular effects 2, 3
• Monitor for dizziness, particularly in the first few days after switching, especially if the patient is elderly or has cardiovascular comorbidities 1, 2
• Ejaculatory dysfunction occurs in 4.5-14% of patients on tamsulosin but is generally reversible 2

Common Pitfalls to Avoid

• Do not create an unnecessary gap between medications—this could delay stone passage and prolong symptoms 4, 1
• Do not assume that switching alpha blockers requires dose titration; tamsulosin can be started at full dose (0.4 mg) immediately 2, 3
• If the patient is planning cataract surgery, inform the ophthalmologist about tamsulosin use due to risk of Intraoperative Floppy Iris Syndrome 2
• Be aware that priapism is a rare but serious adverse effect of tamsulosin, particularly in younger patients 9

Duration of Therapy

• Continue tamsulosin for up to 28 days or until stone passage is confirmed 4, 5, 6
• If the stone has not passed by 28 days, urologic intervention should be considered 4
• After successful stone passage, tamsulosin can be discontinued unless the patient has underlying BPH requiring continued therapy 1, 2