An unusual cause of respiratory failure

The present report describes the case of a 65-year-old white woman with a longstanding diagnosis of medullary thyroid cancer with metastatic disease and an extensive surgical history. She presented with late-onset folliculitis, hypertension, parkinsonian-type syndrome, and respiratory muscle weakness, and she developed chronic hypercapnic respiratory failure during treatment with Vandetanib. Her symptoms improved with reduction of the dosage but then worsened again when the dosage was increased. Prescribing physicians should reduce the dose of Vandetanib to the minimal levels required for therapeutic effect to avoid potentially life-threatening toxic effects.