Is it safe to use Bactrim (trimethoprim/sulfamethoxazole) in patients with glaucoma?

Bactrim (Trimethoprim/Sulfamethoxazole) Use in Patients with Glaucoma

Bactrim (trimethoprim/sulfamethoxazole) should be avoided in patients with glaucoma due to documented cases of acute angle-closure glaucoma that can lead to permanent vision loss.

Mechanism of Bactrim-Induced Glaucoma

Trimethoprim/sulfamethoxazole has been associated with a rare but serious idiosyncratic reaction that can cause:

• Supraciliary choroidal effusion
• Forward displacement of the lens-iris diaphragm
• Secondary angle-closure glaucoma
• Transient myopia
• Anterior chamber shallowing 1

This reaction can occur rapidly after initiating treatment (within days) and may lead to severe consequences if not promptly addressed.

Evidence of Risk

Multiple case reports document the association between trimethoprim/sulfamethoxazole and angle-closure glaucoma:

• A 49-year-old man developed bilateral intraocular pressures exceeding 50 mmHg with 360-degree choroidal effusion after four days of cotrimoxazole prophylaxis, resulting in total cataract and phthisis bulbi despite drug discontinuation 2

• A 20-year-old woman experienced "blindness upon waking" after one week of sulfamethoxazole-trimethoprim treatment, with examination revealing narrowed angles, bilateral 6-D myopic shift, macular folding, and other ocular complications 3

Management Algorithm for Patients Requiring Antibiotics with Glaucoma

1. First-line alternatives to consider:

   • Fluoroquinolones (moxifloxacin 0.5% or gatifloxacin 0.3%) for broad-spectrum coverage 4
   • For prophylaxis in keratoprosthesis patients, consider polymyxin B with a fourth-generation fluoroquinolone instead of trimethoprim 5

2. If Bactrim must be used (no alternatives):

   • Perform baseline ophthalmologic examination including intraocular pressure measurement
   • Educate patient about warning signs: sudden vision changes, eye pain, redness, halos around lights
   • Schedule close monitoring with ophthalmology during treatment
   • Instruct immediate discontinuation and ophthalmology consultation if symptoms develop

3. If angle-closure glaucoma develops:

   • Immediately discontinue trimethoprim/sulfamethoxazole
   • Initiate treatment with:
     • Topical steroids
     • Ocular hypotensive medications
     • Cycloplegic agents 3
   • Monitor until complete resolution of symptoms and normalization of intraocular pressure

Risk Factors for Drug-Induced Glaucoma

Patients with the following are at higher risk and should be monitored more closely:

• Pre-existing narrow anterior chamber angles
• Family history of angle-closure glaucoma
• Hyperopia (farsightedness)
• Advanced age
• Asian ethnicity 6

Important Considerations

1. Drug-induced glaucoma is classified as a form of secondary glaucoma, which can be precipitated by specific medications 6

2. While the exact incidence of Bactrim-induced glaucoma is uncertain, cases of bilateral involvement and blindness have been reported 6, 2

3. The reaction appears to be idiosyncratic rather than dose-dependent, making it difficult to predict which patients will be affected

4. Even with early diagnosis and drug withdrawal, some cases have resulted in permanent vision loss 2

Conclusion

Given the potential for severe, irreversible vision loss, trimethoprim/sulfamethoxazole should be avoided in patients with glaucoma whenever possible. Alternative antibiotics should be selected based on the specific infection being treated and antimicrobial susceptibility patterns.