Oral mexiletine for ventricular tachyarrhythmias treatment in implantable cardioverter-defibrillator patients: a systematic review of the literature

INTRODUCTION

To evaluate the clinical outcomes of oral mexiletine (oMXT) to treat ventricular tachyarrhythmias (VTAs) in the era of implantable cardioverter-defibrillator (ICD) technology.

EVIDENCE ACQUISITION

A systematic search was conducted using PubMed, Embase and Cochrane databases following the PRISMA guidelines to collect literature data reporting oMXT efficacy and safety outcomes in treating VTAs in ICD recipients.

EVIDENCE SYNTHESIS

Final analysis included four studies accounting for a total of 91 patients with recurrent VTAs treated with oMXT. Amiodarone therapy was initially attempted in most patients (91.2%), while catheter ablation was performed in one-third of patients. VTA recurrences were observed in 55/91 patients (60.4%) during oMXT treatment compared to 91/91 (100%) before treatment (P<0.001). Appropriate therapies occurred in 55/88 ICD patients (62.5%) during oMXT treatment compared to 80/88 (90.9%) before treatment (P<0.001). After oMXT introduction, there was a significant reduction of the individual burden of VTA episodes and appropriate ICD therapies per patient, showing Hedges'g values of -1.103 (P=0.002) and -1.474 (P=0.008), respectively. Safety analysis showed a sample-weighted overall side-effect rate of 30%, while 21% of patients required drug reduction or discontinuation. Aggregated meta-regression analysis of the included studies and remote literature revealed a linear correlation between oMXT dosage and the overall side effects rate (r2 = 0.48; P=0.014).

CONCLUSIONS

Oral mexiletine provides an adjunctive treatment to manage VTAs and reduces appropriate therapies in ICD patients with moderate efficacy and acceptable safety profiles. These observations await confirmation through randomised clinical trials.

Methanolic extract of Lupinus termis ameliorates DNA damage in alloxan-induced diabetic mice

Diet therapy is showing a bright future in the therapy of diabetes mellitus (DM). The seeds of Lupinus termis are used in the Middle East and Africa as food and in folklore medicine. In traditional medicine, the seeds are reputed to be effective for diabetes. The aim of this work was to evaluate the antigenotoxic effect of Lupinus termis methanolic extract (LTE) against DM oxidative stress.

MATERIAL AND METHODS

The analysis of micronuclei (MN) and chromosomal aberrations are accurate cytogenetic techniques used to show chromosomal damage caused by clastogenic affects. The present study was designed to evaluate: (1) the effects of DM on bone marrow MN frequency and chromosomal aberrations, (2) the effect of oral treatment by gavage of LTE on MN frequency and chromosomal aberrations produced by DM.

RESULTS

Frequencies of MN and chromosomal aberrations have been significantly increased in diabetic mice compared with the normal mice (p < 0.05). LTE at a dose 25, 50 and 100 mg/kg b.wt. for 15 days groups treatment in diabetic mice were significantly decreased MN frequency and chromosomal aberrations in a dose dependent manner.

CONCLUSIONS

Our results suggest that LTE is a suitable agent for preventing DM-induced DNA damage. To the best of our knowledge, this is the first report on LTE having a potential diabetes-associated DNA damage-protecting activity in vivo.

Malachite green induces genotoxic effect and biochemical disturbances in mice

BACKGROUND AND OBJECTIVES

Malachite green (MG) is a triarylaminmethane dye used in the fish industry as an anti-fungal agent. Concern over MG is due to the potential for consumer exposure, suggestive evidence of tumor promotion in rodent liver, and suspicion of carcinogenicity based on structure-activity relationships. In order to evaluate the risks associated with exposure to MG, we examined the mutagenicity and biochemical effect of MG.

MATERIALS AND METHODS

For genotoxic effect we use the doses 27, 91, 272 and 543 mg/kg b.wt. for different period of time (7, 14, 21 and 28 days) to evaluate chromosomal aberrations in mouse somatic and germ cells as well as sister chromatid exchanges in bone marrow cells. For DNA fragmentation assay from mouse liver the same doses of MG were used for 28 days. For measuring biochemical parameters such as glycolysis and gluconeogenesis enzyme pathways, antioxidant indices, hepatic marker enzymes, total protein, glucose, glycogen levels and liver function enzyme activities were evaluated. Mice were treated orally up to 28 days with the two high doses of MG 272 and 543 mg/kg b.wt.

RESULTS AND CONCLUSIONS

Our results show that MG induce elevation in the percentage of SCE's and chromosomal aberrations (p < 0.01) after treatment with the high doses for long period of time. MG also induces DNA damage in mice liver in a dose dependent manner. Beside, MG treatment either in low or high doses causes biochemical disturbances in the major glucolytic-gluconeogenic pathways, hepatic marker enzymes, depleted glutathione and increased free radical as determined by increasing lipid peroxide. Histopathological observations revealed that MG induced sinusoidal, congestion, focal necrosis and degenerating in hepatic cells, hypertrophy and vacuolization followed by necrosis and cirrhosis.

Design and synthesis of some oxadiazolyl, thiadiazolyl, thiazolidinyl, and thiazolyl derivatives of 1H-pyrazole as anti-inflammatory antimicrobial agents

Four series of 1H-pyrazole derivatives have been synthesized. The first series was prepared by cyclization of the intermediate 3-(5-bromo-2-thienyl)-1-phenyl-1H-pyrazole-4-carbaldehyde aroyl-hydrazone 4a-c with acetic anhydride to afford the corresponding oxadiazoline derivatives 5a-c. The other series were prepared by the cyclization of the intermediate 3-(5-bromo-2-thienyl)-1-phenyl-4-substituted thiocarbamoylhydrazonomethyl-1H-pyrazole 6a-c with acetic anhydride, ethyl bromoacetate or phenacyl bromide giving rise to 3-(5-bromo-2-thienyl)-1-phenyl-4-[3-acetyl-5-(N-substituted acetamido)-2,3-dihydro-1,3,4-thiadiazol-2-yl]-1H-pyrazoles 7a-c, 3-(5-bromo-2-thienyl)-1-phenyl-4-(3-substituted- 4-oxothiazolidin-2-ylidenehydrazonomethyl)-1H-pyrazoles 8a-c, or 3-(5-bromo-2-thienyl)-1-phenyl-4-(3-substituted-4- phenyl-2,3-dihydrothiazol-2-ylidenehydrazonomethyl)-1H-pyraz oles 9a-c respectively. Some of these compounds showed anti-inflammatory, antibacterial or antifungal activities comparable to that of Proquazone, Ampicillin, or Clotrimazole respectively.