Urocit-K XR Shortage: What Providers and Prescribers Need to Know in 2026

Patients with hypocitraturic nephrolithiasis, uric acid lithiasis, and renal tubular acidosis depend on consistent access to potassium citrate extended release (Urocit-K XR) to prevent recurrent stone episodes. While potassium citrate ER is not on the FDA's current official drug shortage list as of 2026, clinicians across urology and nephrology practices are fielding calls from patients unable to fill prescriptions at their usual pharmacy. This article provides a clinical overview of the situation and actionable guidance for prescribers.

Current Availability Status

As of 2026, potassium citrate ER is not listed on the FDA Drug Shortage database, distinguishing it from the widespread shortages affecting ADHD stimulants and certain antibiotics. However, Drugs.com flags ongoing stock shortages affecting specific strengths, particularly 15 mEq tablets. Availability is inconsistent at the pharmacy level — generic formulations from multiple manufacturers are generally more accessible than brand-name Urocit-K. The 10 mEq strength is most reliably stocked; 5 mEq and 15 mEq tablets see more variability by region and pharmacy chain.

Clinical Impact of Supply Gaps

Potassium citrate's therapeutic benefit depends on continuous urinary alkalinization and citrate elevation. Gaps in therapy allow urinary pH and citrate to revert, restoring conditions favorable for calcium oxalate crystallization and uric acid stone formation. For patients with a history of rapid stone recurrence, even brief interruptions carry meaningful risk. Patients on potassium citrate for renal tubular acidosis face additional concerns: metabolic acidosis can return, with implications for bone demineralization and renal function over time.

Evidence-Based Alternatives When Urocit-K XR Is Unavailable

When potassium citrate ER tablets are unavailable, consider the following substitutions based on indication:

For Hypocitraturic Calcium Oxalate Stones

Potassium citrate/citric acid oral solution (Cytra-K): Contains potassium citrate and citric acid in liquid form. Often more readily available than tablets. Typical dosing: 15–30 mEq (3–6 tsp) two to three times daily diluted in water. Adjust to achieve target urinary citrate > 320 mg/day and pH 6.0–7.0.

Thiazide diuretics: Chlorthalidone 25 mg daily or indapamide 1.25–2.5 mg daily are AUA-supported options for hypercalciuric stone formers. Note that thiazides reduce urinary citrate (via hypokalemia-induced intracellular acidosis), so potassium supplementation may be needed.

For Uric Acid Lithiasis

Sodium bicarbonate: 650 mg tablets TID–QID; raises urinary pH effectively but adds sodium load. Avoid in patients with hypertension, heart failure, or sodium-restricted diets.

Allopurinol: 300 mg daily for patients with hyperuricosuria (urinary uric acid > 800 mg/day) or hyperuricemia. AUA recommends this for hyperuricosuric calcium oxalate stone formers with normocalciuria.

For Renal Tubular Acidosis

Sodium citrate/citric acid (Bicitra, Shohl's Solution): Appropriate when potassium supplementation is contraindicated. Provides equivalent alkalinization without the potassium load.

Prescribing Tips to Improve Patient Access

Write prescriptions allowing generic substitution. Most patients can use generic potassium citrate ER, which is more widely stocked than brand-name Urocit-K.

Avoid brand-only prescriptions unless clinically required. Brand-name Urocit-K can cost $217–$364 per 100 tablets; generic is widely available at $13–$40 with coupons.

Prescribe dose-equivalent strengths. If 15 mEq tablets are unavailable, three 5 mEq tablets or 1.5 × 10 mEq tablets can deliver equivalent mEq per dose.

Direct patients to medfinder. medfinder calls pharmacies near the patient to check real-time Urocit-K XR availability, reducing the administrative burden on your office staff.

Recommend mail-order pharmacy. For stable maintenance patients, a 90-day supply through a mail-order pharmacy is the most reliable long-term approach.

Monitoring During Supply Gaps

Patients who are unable to fill their prescription for more than a few days should be advised to maximize fluid intake (> 2 L/day), reduce sodium intake, and consume citrate-rich foods (lemons, limes). Repeat 24-hour urine testing is warranted after an extended supply gap to assess for return of stone-promoting urinary chemistry. For patients with RTA, monitor serum bicarbonate and potassium.

To refer patients to a pharmacy search service, visit medfinder for providers for resources to share with your practice.