Disproportionality analysis of buprenorphine transdermal system and cardiac arrhythmia using FDA and WHO postmarketing reporting system data.

OBJECTIVE: Positive-controlled clinical studies have shown a dose dependent effect of buprenorphine transdermal system on QTc interval prolongation. This study provides assessment of the buprenorphine transdermal system and cardiac arrhythmia using US FDA and WHO postmarketing reporting databases. METHODS: Disproportionality analysis of spontaneously reported adverse events to assess whether the reporting rate of cardiac arrhythmia events was disproportionately elevated relative to expected rates of reporting in both FDA and WHO databases. Cardiac arrhythmia events were identified using the standardized Medical Dictionary for Regulatory Activities query for torsade de pointes and/or QT prolongation (TdP/QTP). The threshold for a signal of disproportionate adverse event reporting was defined as the lower 90% confidence limit ≥ 2 of the Empiric Bayes geometric mean in FDA database and as the lower 95% confidence limit of the Informational Component >0 in WHO database. RESULTS: There were 124 (<1%) and 77 (2%) cardiac arrhythmia event cases associated with buprenorphine transdermal as compared to 3206 (12%) and 2913 (14%) involving methadone in the FDA and WHO databases, respectively. In the FDA database methadone was associated with a signal of disproportionate reporting for TdP/QTP (EB05 3.26); however, buprenorphine transdermal was not (EB05 0.33). In the WHO database methadone was associated with a signal of disproportionate reporting for TdP/QTP (IC025 2.66); however, buprenorphine transdermal was not (IC025 -0.88). Similar trends were observed in sensitivity analyses by age, gender, and specific terms related to ventricular arrhythmia. CONCLUSIONS: The signal identified in the transdermal buprenorphine thorough QTc study, which led to a dose limitation in its US label, does not translate into a signal of increased risk for cardiac arrhythmia in real world use, as assessed by this method of analyzing post-market surveillance data.

Enfuvirtide plasma levels and injection site reactions using a needle-free gas-powered injection system (Biojector).

OBJECTIVES: To assess the use of the Biojector B2000 needle-free gas-powered injection system for subcutaneous administration of enfuvirtide in HIV-infected patients and to compare this system with standard needles and syringes with respect to ease of use, severity of injection site reactions (ISR), and enfuvirtide plasma levels. DESIGN: An observational study among 32 treatment-experienced HIV clinic patients receiving enfuvirtide. METHODS: Adult patients were assessed before and after switching from standard needles to the Biojector for enfuvirtide administration. Patients used the Biojector for up to 24 weeks and rated ease of use from 0 (easy) to 3 (difficult). ISR were graded from 0 to 31 for signs and symptoms (erythema, induration, pruritus, nodules/cysts, ecchymosis), duration of individual lesions, and number of lesions. Plasma was collected pre-dose and 1 h post-dose for enfuvirtide measurement. The high-pressure liquid chromatography with tandem mass spectrometry method used was specific for enfuvirtide over its known plasma metabolite. Wilcoxon rank sum tests were used to compare needle-based and Biojector outcomes. RESULTS: The Biojector was rated as being significantly easier to use (P < 0.001) and reduced the occurrence of ISR compared with standard needles (P < 0.001). Enfuvirtide plasma levels were not statistically different between the two administration methods at either pre-dose trough (P = 0.41) or 1 h post-dose (P = 0.74). CONCLUSIONS: The Biojector needle-free injection system was easy to use for enfuvirtide administration and was associated with a decreased severity of ISR. Plasma enfuvirtide levels pre-dose and 1 h post-dose were comparable when injecting with standard needles or the Biojector.

Studies on the use of needle-free injection device on proteins.

In the following communication we report the evaluation of 18 proteins that were processed by a specific needle free injection device. The processed protein samples were analyzed by two HPLC techniques, reversed-phase liquid chromatography (RPLC) and size-exclusion chromatography (SEC). These techniques are two of the most widely used analytical techniques in the biopharmaceutical industry for the characterization, integrity assessment and stability study of peptide and protein products. The results indicate that needle free injection, using the specific device of this study, is not damaging to the studied proteins and does not generate aggregates. We found no evidence of the predicted possible effects of needle free injections, and concluded that needle free delivery is in general not different than any other delivery system and that its use should be evaluated on a case by case basis. It has to be noted that there are various needle free device designs and our work was performed using an Iject from Bioject. Our conclusions therefore should be limited to the Iject design we used in this study. In the reported experiments we used commercially available (economical) model proteins, which facilitate the use of the results for future comparison and reference. The work reported here can serve as a reference to illustrate the benign nature of our needle free injection device. It also highlights an interesting analogy between a set of phobias that were seen to have plagued the early stages of biochemistry and HPLC, on the one hand, and some attitudes that appear to hinder the widespread acceptance of needle free injection at present time, on the other. These phobias were identified and named by Professor Csaba Horváth, the father of HPLC, as barophobia, siderophobia and lithophobia. Today a wealth of evidence is available to indicate that those phobias are ungrounded and that the negative observations can be explained in most cases by adsorption and prevented by proper formulations and solvent conditions.