Two case reports of zoledronic acid-induced uveitis

Case report: A severe case of zoledronate-associated diffuse orbital inflammation and uveitis in a patient with metastatic breast cancer

Introduction

Zoledronate is a commonly prescribed medication to maintain bone health; however, a rare side effect includes ocular inflammation. We report a case of simultaneous anterior uveitis and orbital inflammation associated with zoledronate infusion in a patient with metastatic breast cancer. We also performed a literature search to provide an up-to-date summary of cases with zoledronate-associated ocular inflammation.

Methods

This is a case report with literature review. Literature search (timeline 2010 to 2023) was performed using PubMed with the search team: (zoledronate) AND (uveitis OR scleritis OR orbital inflammation OR ocular inflammation).

Results

A 48-year-old female presented with left eye pain, swelling, and decreased vision 2 days after receiving zoledronic acid infusion. An ophthalmic exam showed non-granulomatous anterior uveitis. CT orbits and ocular ultrasound showed signs of posterior scleritis and orbital inflammation. Ocular inflammation caused by an infection or metastatic cancer was ruled out. The patient was treated with both topical and systemic corticosteroids. Complete resolution of the inflammation occurred after 2.5 weeks.

Conclusion

Orbital inflammation and uveitis are an uncommon side effect of zoledronate but needs to be promptly recognized and treated to prevent sight-threatening complications.

Ocular Side Effects of Bisphosphonates: A Review of Literature

In rare cases, bisphosphonates are well established to cause ocular inflammation, presenting as uveitis, episcleritis, scleritis, orbital inflammation, and/or conjunctivitis. Some reports of bisphosphonate-associated neuro-ophthalmic complications also exist. We identified 101 reports in the literature relating to bisphosphonate-associated ocular complications. In a great majority of cases, symptoms resolve after discontinuation of the drug and anti-inflammatory treatment. Many cases recur if rechallenged with the same bisphosphonate. First-generation nonamino bisphosphonates, including clodronate and etidronate, are not associated with ocular inflammation. Only 2nd- and 3rd-generation amino bisphosphonates, including pamidronate, alendronate, risedronate, ibandronate, and zoledronate are associated with these complications. The mechanism of bisphosphonate-induced ocular inflammation may be related to activation of γ/δ T cells or M1 macrophages. Intravenous forms, such as pamidronate and zoledronate, tend to have higher rates and faster onset of ocular inflammation, generally presenting within days of infusion. In oral bisphosphonates, such as alendronate and risedronate, these complications present with more sporadic timing. Rates of complications are also higher when bisphosphonates are used for malignancy, as doses tend to be higher compared with doses for osteoporosis.

Evaluation of zoledronate for the treatment of canine stage III osteosarcoma: A phase II study

BACKGROUND

Greater than 90% of dogs with appendicular osteosarcoma will develop pulmonary metastasis despite the standard of care. Available treatments have limited efficacy for stage III disease. Zoledronate, a bisphosphonate, induces apoptosis of canine osteosarcoma cells and appears to modulate the tumour microenvironment.

OBJECTIVES

This prospective, single institutional phase IIa trial investigated the use of single agent zoledronate in dogs with pulmonary metastases from osteosarcoma.

METHODS

Zoledronate was administered once monthly, and thoracic radiographs were used to assess response.

RESULTS

Eleven dogs were enrolled. Stable disease was achieved in two of eight dogs available for response assessment. The median progression-free survival was 28 days (range: 4-93 days). The median stage III-specific survival time was 92 days. Adverse events were reported in four dogs; two dogs developed grade III or higher toxicities. Notable adverse events included conjunctivitis, fever, hypocalcaemia, and hypophosphatemia.

CONCLUSIONS

Zoledronate appears to have limited efficacy as a single agent for stage III osteosarcoma and may be associated with unexpected toxicity in this population. This clinical trial was registered on the AVMA Animal Health Studies Database (AAHSD004396).

Pharmacologically induced uveitis

Treatments of numerous systemic and local diseases of different etiologies may be accompanied by an unwanted side effect in the form of uveitis. We inform readers about medications that have the potential to cause uveitis and analyze the strength of association of these medications with uveitis. Subsequently, cessation of medication or appropriate treatment can be individualized for each patient for the purpose of preventing further damage to tissue structure and function. Being aware of these associations, physicians may readily identify medications that may cause uveitis and avoid expensive and unnecessary clinical and laboratory testing.

Acute unilateral anterior uveitis following zoledronic acid infusion: A case report

Bisphosphonates are widely used to treat several clinical conditions. Zoledronic acid is one of this class, commonly used for the treatment and prevention of osteoporosis, hypercalcemia of malignancy, Paget's disease, and multiple myeloma. A variety of ocular side effects associated with bisphosphonates therapy has been reported but are uncommon and readily treatable. Most of these ocular inflammatory conditions are associated with other bisphosphonates such as pamidronate but rarely reported with zoledronic acid. Acute anterior uveitis associated with zoledronic acid is rare. We describe a 75-year-old female who presented with features of acute unilateral non-granulomatous anterior uveitis which developed within 24 h following the first dose of intravenous infusion of zoledronic acid administered to treat post-menopausal osteoporosis. She was treated with topical steroids and made an uneventful recovery in 2 weeks.