Your Patients Can't Find Tobrex — Here's How You Can Help

As a prescriber, few things are more frustrating than writing a prescription you know your patient needs, only to have them call back saying the pharmacy can't fill it. With Tobramycin ophthalmic (Tobrex) experiencing ongoing supply disruptions in 2026, this scenario has become all too common for ophthalmologists, optometrists, primary care physicians, and urgent care providers.

This guide provides practical, actionable steps you can integrate into your clinical workflow to help patients access Tobramycin or appropriate alternatives without unnecessary delays.

Current Availability of Tobrex and Tobramycin

As of early 2026, the availability picture for Tobramycin ophthalmic is mixed:

• Brand-name Tobrex: Limited and inconsistent. Fewer manufacturers produce the brand, making it vulnerable to supply gaps.
• Generic Tobramycin solution (0.3%): More widely available than the brand, but still subject to intermittent shortages in some regions.
• Tobramycin ointment (0.3%): Generally less affected by shortages than the solution form.
• Regional variation: Availability can differ significantly by city, pharmacy chain, and distribution network.

The core challenge is that sterile ophthalmic manufacturing capacity remains constrained industry-wide, and Tobramycin is one of several ophthalmic products affected.

Why Your Patients Can't Find It

Understanding the supply-side dynamics helps frame the problem:

Sterile Manufacturing Bottleneck

Ophthalmic products require specialized sterile manufacturing facilities. Industry consolidation has reduced the number of active facilities, and FDA enforcement actions related to quality issues have further limited capacity. New facilities take years to build and qualify.

Wholesaler Allocation

During shortages, wholesalers often place products on allocation — meaning pharmacies can only order limited quantities based on their historical purchasing patterns. This means pharmacies that historically dispensed less Tobramycin may receive very small allocations or none at all.

Chain Pharmacy Distribution Limitations

Large chain pharmacies typically use a single primary wholesaler, limiting their sourcing flexibility. When that wholesaler is on allocation, the chain's entire network may be affected simultaneously.

Patient Behavior

When patients hear about shortages, some attempt to fill prescriptions early or at multiple pharmacies. While understandable, this behavior can exacerbate localized shortages.

What Providers Can Do: 5 Practical Steps

Step 1: Prescribe Generically

This is the single most impactful action you can take. Write prescriptions for "Tobramycin ophthalmic solution 0.3%" rather than "Tobrex." Avoid "Dispense as Written" or "Brand Necessary" designations unless there's a documented clinical reason. Generic prescribing gives the pharmacist maximum flexibility to fill from whatever manufacturer has available stock.

Step 2: Check Availability Before the Patient Leaves

Rather than sending patients out with a prescription and hoping for the best, take 30 seconds to check pharmacy availability. Medfinder for Providers allows your staff to verify which nearby pharmacies have Tobramycin in stock and direct the patient accordingly. This small step can prevent callbacks, delayed treatment, and patient frustration.

Consider assigning this check to a medical assistant or front desk staff member as part of the checkout workflow for any shortage-affected medication.

Step 3: Pre-Authorize Alternatives

Proactively document in your prescription or patient instructions that if Tobramycin is unavailable, the pharmacist may contact your office for an alternative. Better yet, consider writing a primary prescription for Tobramycin with a noted alternative — for example, adding a comment that Ciprofloxacin ophthalmic is an acceptable substitute if Tobramycin is out of stock.

While pharmacists cannot independently substitute a different drug (unlike generic substitution), having a pre-discussed alternative speeds the process when a change is needed.

Step 4: Maintain a Quick-Reference Alternatives List

Keep a readily accessible reference for your staff listing the primary therapeutic alternatives with dosing:

• Ciprofloxacin ophthalmic 0.3% (Ciloxan): 1-2 drops q2h while awake x2 days, then q4h x5 days. Comparable gram-negative coverage. Generic available ($10-$30).
• Moxifloxacin ophthalmic 0.5% (Vigamox): 1 drop TID x7 days. Broad spectrum including enhanced gram-positive. Generic available ($20-$60).
• Polymyxin B/Trimethoprim (Polytrim): 1 drop q3h (max 6 doses/day) x7-10 days. Good for straightforward conjunctivitis. Very affordable ($10-$25).
• Erythromycin ophthalmic ointment 0.5%: ½-inch ribbon up to 6x daily. Gram-positive focus. Best for mild infections ($8-$20).

For detailed information on each alternative, see our alternatives guide.

Step 5: Educate Patients Proactively

When prescribing Tobramycin, take a moment to set expectations:

• Explain that supply may be limited and the pharmacy might need to order it or substitute a generic.
• Advise them to ask for the generic if the brand isn't available.
• Provide guidance on what to do if the pharmacy is completely out — who to call at your office, and that alternatives are available.
• Direct them to resources like Medfinder for locating pharmacies with stock.

Proactive communication prevents panicked phone calls and ensures patients don't delay treatment while waiting for a specific product.

Therapeutic Alternatives: Clinical Considerations

When switching from Tobramycin to an alternative, consider these clinical factors:

For Bacterial Conjunctivitis

Any of the four alternatives listed above is appropriate for typical bacterial conjunctivitis. From an antibiotic stewardship perspective, Polytrim or Erythromycin ointment may be preferable over fluoroquinolones for uncomplicated cases.

For Keratitis and Corneal Ulcers

Fluoroquinolones (Ciprofloxacin or Moxifloxacin) are the preferred alternatives. These conditions require broad-spectrum coverage, and the fluoroquinolones have well-established efficacy. Polytrim and Erythromycin are generally not appropriate for severe corneal infections.

For Surgical Prophylaxis

Moxifloxacin has become the standard of care for pre- and post-operative prophylaxis in many ophthalmic surgery settings. If you've been using Tobramycin for this purpose, Moxifloxacin is the most direct replacement.

For Pediatric Patients

Tobramycin is approved for children 2 months and older. Most alternatives are similarly approved, but verify age-specific indications. Erythromycin ointment has the longest safety record in neonates and young infants.

Workflow Tips for Your Practice

Integrating shortage management into your daily workflow doesn't have to be burdensome:

• EHR alerts: If your EHR supports it, add a prescribing alert for Tobramycin noting the shortage and suggesting alternatives.
• Template prescriptions: Create prescription templates for your top 2-3 alternatives so switching takes seconds, not minutes.
• Staff training: Brief your medical assistants and front desk staff on the shortage so they can field patient calls knowledgeably and check Medfinder before patients leave.
• Pharmacy partnerships: Establish relationships with 2-3 reliable pharmacies (including at least one independent pharmacy) that tend to have consistent ophthalmic antibiotic stock.
• Bookmark Medfinder: Keep Medfinder for Providers bookmarked on workstations for quick availability checks.

Final Thoughts

The Tobramycin ophthalmic shortage is a supply-side problem that providers can mitigate through proactive prescribing, availability checking, and patient education. By prescribing generically, verifying availability before patients leave, maintaining familiarity with alternatives, and leveraging tools like Medfinder for Providers, you can ensure that supply disruptions don't translate into treatment delays.

For the broader clinical picture on this shortage, see our companion article: Tobrex shortage: what providers and prescribers need to know in 2026.