Use of antihistamines and risk of ventricular tachyarrhythmia: a nested case-control study in five European countries from the ARITMO project.

PURPOSE: After regulatory restrictions for terfenadine and astemizole in '90s, only scarce evidence on proarrhythmic potential of antihistamines has been published. We evaluate the risk of ventricular tachyarrhythmia (VA) related to the use of individual antihistamines. METHODS: A matched case-control study nested in a cohort of new users of antihistamines was conducted within the EU-funded ARITMO project. Data on 1997-2010 were retrieved from seven healthcare databases: AARHUS (Denmark), GEPARD (Germany), HSD and ERD (Italy), PHARMO and IPCI (Netherlands) and THIN (UK). Cases of VA were selected and up to 100 controls were matched to each case. The odds ratio (OR) of current use for individual antihistamines (AHs) was estimated using conditional logistic regression. RESULTS: For agents largely used to prevent allergic symptoms, such as cetirizine, levocetirizine, loratadine, desloratadine and fexofenadine, we found no VA risk. A statistically significant, increased risk of VA was found only for current use of cyclizine in the pooled analysis (ORadj, 5.3; 3.6-7.6) and in THIN (ORadj, 5.3; 95% CI, 3.7-7.6), for dimetindene in GEPARD (ORadj, 3.9; 1.1-14.7) and for ebastine in GEPARD (ORadj, 3.3; 1.1-10.8) and PHARMO (ORadj, 4.6; 1.3-16.2). CONCLUSIONS: The risk of VA associated with a few specific antihistamines could be ascribable to heterogeneity in pattern of use or in receptor binding profile.

Pattern of drug use among preterm neonates: results from an Italian neonatal intensive care unit.

BACKGROUND: Drug use in preterm neonates admitted to Neonatal Intensive Care Unit (NICU) has been investigated, so far, in terms of unauthorized or off-label use; very little is known on the use of combinations of different active substances, which is frequently required in this population (prophylaxis of infections, treatment of concomitant diseases). The aim of this study was to describe the most common patterns of drug use in an Italian NICU, focusing on those with nephrotoxic potential. METHODS: Medical records of preterm neonates (<37 weeks of gestational age) weighing less than 1,500 g at birth and admitted to an Italian NICU were scrutinized in a 3-year retrospective investigation. Analysis included drug exposure, duration of therapies, co-administration of drugs with potential renal side effects; also daily protein supplement was calculated from parenteral nutrition. RESULTS: A cohort of 159 preterm neonates was selected; 68 were born weighing less than 1,000 g (extremely low birth weight infants, ELBW, Group A), 91 weighed between 1,000 and 1,500 g at birth (Group B). Compared to Group B, neonates of Group A were more likely to receive pharmacological treatments: the most used drugs were antibiotics (especially ampicillin and amikacin, p = .07 and p < .001, respectively), antifungals (especially fluconazole, p < .001), and diuretics (especially furosemide, p < .001). Analysis of co-administration of drugs with potential nephrotoxicity showed ampicillin and amikacin as the most reported combination (94.1% of Group A and 31.9% of Group B), the combination of furosemide with antibacterials (ampicillin or amikacin) was also frequently reported, with average period of combination shorter than 2 days. CONCLUSIONS: ELBW infants were exposed to a higher number of drugs compared to other neonates and were more likely to receive associations of drugs with nephrotoxic potential (e.g. furosemide and amikacin), though only for short cycles. Further studies should evaluate the safety profile (especially potential renal side effects) related to most commonly used combinations.

Dipeptidyl peptidase-4 inhibitors and heart failure: Analysis of spontaneous reports submitted to the FDA Adverse Event Reporting System.

BACKGROUND AND AIMS: We tested the possible association between dipeptidyl peptidase-4 inhibitors (DPP-4-I) use and heart failure (HF) occurrence by assessing the publicly available US-FDA Adverse Event Reporting System (FAERS). METHODS: FAERS data reporting HF and DPP-4-Is use in the period from the fourth quarter of 2006 through 2013 were extracted, using the Standardized MedDRA Query "Cardiac failure". Disproportionality (case/non-case method) was implemented by calculating Reporting Odds Ratios (RORs) with 95% Confidence Interval (CI): (1) exploratory analysis on the entire FAERS (using rosiglitazone as positive control); (2) consolidated analyses by therapeutic area (within antidiabetics), correcting for event- and drug-related competition bias and adjusting for co-reported drugs as confounders. RESULTS: HF during DPP4-I use was recorded in 390 reports (4.4% of total reports). In exploratory analysis, statistically significant ROR emerged for DPP-4-I as a class (ROR = 1.17; 95% CI = 1.05-1.29), saxagliptin (1.68; 1.29-2.17), vildagliptin (2.39; 1.38-4.14), and rosiglitazone (13.98; 13.30-14.70). In consolidated analyses, the ROR for saxagliptin (2.60; 1.92-3.50) and vildagliptin (4.07; 2.28-7.27) increased, and became also significant for sitagliptin (1.61; 1.40-1.86). Concomitant drugs were reported in more than 50% of cases; the adjusted RORs of saxagliptin (2.30; 1.70-3.10), vildagliptin (3.15; 1.76-5.63), and sitagliptin (1.48; 1.28-1.71) were nonetheless significant. CONCLUSION: FAERS data are consistent with clinical studies on a possible association between saxagliptin and HF. The disproportionate reporting of HF with sitagliptin, conflicting with a recent phase IV trial, suggests that cardiovascular safety requires close post-marketing vigilance by clinicians of individual DPP-4-I in the community until the issue of class effect is solved.