Metamizole for Postoperative Pain Therapy in Infants Younger than 1 Year.

Background Due to possible serious adverse drug reactions (ADRs), the use of metamizole for postoperative pain therapy in infants is a subject of debate. Safety studies with large sample sizes are missing. Aim This prospective multicenter observational study was conducted to evaluate the use of metamizole in infants younger than 1 year undergoing surgery with a particular focus on possible serious ADRs (e.g., hemodynamic, anaphylactic or respiratory reactions, and agranulocytosis). Methods Infants aged up to 1 year (American Society of Anesthesiologists [ASA] I-III) receiving a single dose of metamizole for postoperative pain therapy were enrolled. Patient demographics, main and secondary diagnosis, surgical procedures performed, metamizole dose, hemodynamic data, use of other analgesics and regional blocks, results of pain measurement, and incidence of ADRs were documented using a standardized case report form. Results A total of 316 infants observed at five pediatric centers were included for analysis (age 4.4 ± 3.7 [0.06-12] months). Mean metamizole dose was 17.8 ± 3.1 (9.2-29.8) mg·kg-1. Mean arterial pressure (MAP) remained stable during metamizole infusion (MAP before infusion 45 ± 9.5 [25-95] and after infusion 45 ± 9.2 [25-99] mm Hg). Erythema was observed in one patient (ADRs total: 0.3%, 95% confidence interval: 0.27-0.32). No respiratory adverse events directly related to the metamizole administration and no clinical signs of agranulocytosis were reported. Conclusion Single intravenous doses of metamizole used for prevention or treatment of postoperative pain were safe in more than 300 infants younger than 1 year. The statistical probability of serious ADRs (e.g., hemodynamic, anaphylactic or respiratory reactions) was lower than 1%. The sample size and follow-up were not sufficient to detect agranulocytosis.

Metamizole for postoperative pain therapy in 1177 children: A prospective, multicentre, observational, postauthorisation safety study.

BACKGROUND: Due to possible serious adverse drug reactions (ADRs), the use of metamizole for postoperative pain therapy in children is a subject of debate. Safety studies with large sample sizes have not been published as yet. OBJECTIVE: The aim of this study was to evaluate the use of metamizole in children aged up to 6 years undergoing surgery with a particular focus on serious ADRs such as haemodynamic, anaphylactic or respiratory reactions and agranulocytosis. DESIGN: A multicentre, prospective, noninterventional, observational postauthorisation safety study (PASS). SETTING: The study was conducted in six different paediatric centres from September 2013 to September 2014. PATIENTS: One thousand one hundred and seventy-seven children aged up to six years (American Society of Anesthesiologists' physical status class I to III) receiving a single dose of metamizole for postoperative pain therapy were enrolled. MAIN OUTCOME MEASURES: Patient demographics, main and secondary diagnoses, surgical procedures performed, metamizole dose, haemodynamic data, use of other analgesics and regional blocks, results of pain measurement (Children and Infants Postoperative Pain Scale, ChIPPS) and ADR incidence were documented using a standardised case report form. RESULTS: Of the 1177 children observed at six paediatric centres, 1145 were included for analysis [age 35.8 ± 18.1 (0.1 to 72) months]. The mean metamizole dose was 17.3 ± 2.9 (8.3 to 29.4) mg kg(-1). Mean arterial pressure (MAP) remained stable during metamizole infusion [baseline 55.7 ± 1.3 (25 to 98) and after infusion 56.6 ± 11.3 (25 to 99) mmHg; P < 0.01]. Pruritus, swelling and exanthema were observed in one patient each (total 0.3%). No respiratory adverse events directly related to the metamizole administration and no clinical signs of agranulocytosis were reported. All data are mean ± SD (range). CONCLUSION: Single intravenous doses of metamizole used for the prevention or treatment of postoperative pain were well tolerated in more than 1000 children aged up to 6 years. The probability of serious ADRs (haemodynamic, anaphylactic or respiratory reactions) is lower than 0.3%. The sample size and follow-up was not sufficient to detect episodes of agranulocytosis.

Prognostic factors for remission of and survival in acquired hemophilia A (AHA): results from the GTH-AH 01/2010 study.

Acquired hemophilia A (AHA) is caused by autoantibodies against factor VIII (FVIII). Immunosuppressive treatment (IST) results in remission of disease in 60% to 80% of patients over a period of days to months. IST is associated with frequent adverse events, including infections as a leading cause of death. Predictors of time to remission could help guide IST intensity but have not been established. We analyzed prognostic factors in 102 prospectively enrolled patients treated with a uniform IST protocol. Partial remission (PR; defined as no active bleeding, FVIII restored >50 IU/dL, hemostatic treatment stopped >24 hours) was achieved by 83% of patients after a median of 31 days (range 7-362). Patients with baseline FVIII <1 IU/dL achieved PR less often and later (77%, 43 days) than patients with ≥1 IU/dL (89%, 24 days). After adjustment for other baseline characteristics, low FVIII remained associated with a lower rate of PR (hazard ratio 0.52, 95% confidence interval 0.33-0.81, P < .01). In contrast, PR achieved on steroids alone within ≤21 days was more common in patients with FVIII ≥1 IU/dL and inhibitor concentration <20 BU/mL (odds ratio 11.2, P < .0001). Low FVIII was also associated with a lower rate of complete remission and decreased survival. In conclusion, presenting FVIII and inhibitor concentration are potentially useful to tailor IST in AHA.