Long-term, prolonged-release oral tapentadol for the treatment of refractory chronic low back pain: a single-center, observational study.

BACKGROUND: Chronic back pain is a leading cause of disability worldwide and it is still inadequately treated. Tapentadol is a dual-acting analgesic drug µ-opioid receptor (MOR) agonist/norepinephrine reuptake inhibitor, carrying a lower risk for opioid withdrawal symptoms and opioid-related adverse effects in comparison to potent opioid drugs. This study investigates the effectiveness, safety and tolerability of the prolonged release oral formulation of tapentadol (tapentadol PR) in 27 patients affected by refractory chronic low back pain during a long-term follow-up (up to 51 months). METHODS: This is an observational study conducted at the Pain Therapy and Palliative Care Unit of University Hospital of Cagliari, Italy. We enrolled 27 patients affected by chronic low back pain refractory to other pharmacological treatments according to the inclusion criteria. We prospectively evaluated oral tapentadol PR therapy during a long-term follow-up (up to 51 months) according to the following outcomes: pain intensity during the previous 72 hours (Numeric Rating Scale 3), quality of life (Short Form-12 Health Survey), self-reported treatment effectiveness (Patient Global Impression of Change scale), physician evaluation of treatment effectiveness (Clinician Global Impression of Change scale), treatment-related adverse effects, reason for tapentadol therapy interruption and tapentadol dosage. RESULTS: All the patients reported a significant improvement of pain intensity and quality of life at the last follow-up. CONCLUSIONS: These results show the long-term effectiveness, safety and tolerability of oral tapentadol PR for the treatment of refractory chronic low back pain in a real-life clinical setting.

Metformin-associated lactic acidosis and temporary ileostomy: a case report.

INTRODUCTION: Lactic acidosis is a well-known complication of the anti-hyperglycemic biguanide agent metformin, especially in peculiar but not rare clinical conditions. Attempts to reduce the incidence of this adverse reaction have been enforced by national agencies over the years. The Italian Medicines Agency recently released a safety recommendation on prescribing the drug and with regard to the existence of several conditions that contraindicate drug continuation, such as dehydration, infection, hypotension, surgery or hyperosmolar contrast agent infusion, but the recommendation does not mention the increased risk related to stoma. The present case report is, to our knowledge, the first in the literature of metformin-associated lactic acidosis in a patient with a recently created ileostomy and low anterior resection for rectal cancer. CASE PRESENTATION: A 70-year-old Caucasian man who had undergone low anterior resection with total mesorectal excision and temporary loop ileostomy creation at our institution returned to our department 30 days later because of nausea, vomiting, diffuse abdominal pain and anuria of about 24 hours' duration. During his physical examination, the patient appeared dehydrated and had tachypnea and a reduced level of consciousness. His laboratory tests showed that he had acute kidney injury and severe lactic acidosis. CONCLUSION: An ileostomy puts patients at high risk for output losses that can lead to dehydration and electrolyte abnormalities. The assessment of the losses through the stoma, especially the ileostomy, should be added to the recommendations issued by pharmacovigilance societies. The present clinical case illustrates the need for clinicians on surgical wards to carefully evaluate patients before resuming metformin therapy and to provide appropriate information at discharge to patients with type 2 diabetes mellitus who have undergone ileostomy. Furthermore, this case report highlights the increasing need for more training of general physicians regarding both surgical and internal medicine problems that may arise in the post-operative course after major surgery in patients with co-morbidities.