[Relapse of chronic inflammatory demyelinating polyneuropathy following treatment with zoledronic acid]

Zoledronic acid is a nitrogen-containing bisphosphonate that is frequently used in the treatment of osteoporosis. Many patients experience a so-called acute-phase reaction during initial treatment; this is characterized by flu-like symptoms and fever.

We describe a 61-year-old woman who suffered from chronic inflammatory demyelinating polyneuropathy (CIDP), and who was started on intravenous zoledronic acid treatment as adjuvant therapy for breast cancer. Within 24 hours of the initial treatment she developed cold shivers, extreme fatigue, muscle pain and headache. These symptoms resolved spontaneously in the course of the following days. At the same time, she also experienced a CIDP relapse, with a tingling sensation in her arms and legs and deterioration in her ability to walk. Considering the course of the symptoms and the absence of any other cause, CIDP relapse was very probably the result of the acute-phase reaction induced by zoledronic acid.

Caution is warranted when using nitrogen-containing bisphosphonates such as zoledronic acid, particularly in patients with known neuromuscular disorders.