title: N-Acetyl-Cysteine as Effective and Safe Chelating Agent in Metal-on-Metal Hip-Implanted Patients: Two Cases.
abstract: Systemic toxicity associated with cobalt (Co) and chromium (Cr) containing metal hip alloy may result in neuropathy, cardiomyopathy, and hypothyroidism. However clinical management concerning chelating therapy is still debated in literature. Here are described two metal-on-metal hip-implanted patients in which N-acetyl-cysteine decreased elevated blood metal levels. A 67-year-old male who underwent Co/Cr hip implant in September 2009 referred to our Poison Control Centre for persisting elevated Co/Cr blood levels (from March 2012 to November 2014). After receiving oral high-dose N-acetyl-cysteine, Co/Cr blood concentrations dropped by 86% and 87% of the prechelation levels, respectively, and persisted at these latter concentrations during the following 6 months of follow-up. An 81-year-old female who underwent Co/Cr hip implant in January 2007 referred to our Centre for detection of high Co and Cr blood levels in June 2012. No hip revision was indicated. After a therapy with oral high-dose N-acetyl-cysteine Co/Cr blood concentrations decreased of 45% and 24% of the prechelation levels. Chelating agents reported in hip-implanted patients (EDTA, DMPS, and BAL) are described in few cases. N-acetyl-cysteine may provide chelating sites for metals and in our cases reduced Co and Cr blood levels and resulted well tolerable.
authors.affiliation: Pavia Poison Centre and National Toxicology Information Centre, IRCCS Maugeri Foundation Clinical Institute and University of Pavia, 27100 Pavia, Italy.
authors.forename: Andrea
authors.identifier: 0000-0002-7262-7924
authors.initials: A
authors.lastname: Giampreti
authors.affiliation: Pavia Poison Centre and National Toxicology Information Centre, IRCCS Maugeri Foundation Clinical Institute and University of Pavia, 27100 Pavia, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Lonati
authors.affiliation: Diabetes Agency, Careggi Teaching Hospital, 50134 Firenze, Italy.
authors.forename: Benedetta
authors.initials: B
authors.lastname: Ragghianti
authors.affiliation: Pavia Poison Centre and National Toxicology Information Centre, IRCCS Maugeri Foundation Clinical Institute and University of Pavia, 27100 Pavia, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Ronchi
authors.affiliation: Pavia Poison Centre and National Toxicology Information Centre, IRCCS Maugeri Foundation Clinical Institute and University of Pavia, 27100 Pavia, Italy.
authors.forename: Valeria Margherita
authors.identifier: 0000-0002-4538-6993
authors.initials: VM
authors.lastname: Petrolini
authors.affiliation: Pavia Poison Centre and National Toxicology Information Centre, IRCCS Maugeri Foundation Clinical Institute and University of Pavia, 27100 Pavia, Italy.
authors.forename: Sarah
authors.initials: S
authors.lastname: Vecchio
authors.affiliation: Pavia Poison Centre and National Toxicology Information Centre, IRCCS Maugeri Foundation Clinical Institute and University of Pavia, 27100 Pavia, Italy.
authors.forename: Carlo Alessandro
authors.initials: CA
authors.lastname: Locatelli