An international randomized study with long-term follow-up of single versus combination chemotherapy of multibacillary leprosy

Characterization of the anticonvulsant effect of dapsone on metabolic activity assessed by [18F]FDG -PET after kainic acid-induced status epilepticus in rats

BACKGROUND

Development of effective drugs for epilepsy are needed, as nearly 30 % of epileptic patients, are resistant to current treatments. This study is aimed to characterize the anticonvulsant effect of dapsone (DDS), in the kainic acid (KA)-induced Status Epilepticus (SE) by recording the brain metabolic activity with an [¹⁸F]FDG-PET analysis.

METHODS

Wistar rats received KA (10 mg/kg, i.p., single dose) to produce sustained seizures. [¹⁸F]FDG-PET and electroencephalographic (EEG) studies were then performed. DDS or vehicle were administered 30 min before KA. [¹⁸F]FDG uptake and EEG were evaluated at baseline, 2 and 25 h after KA injection. Likewise, caspase-8, 3 hippocampal activities and Fluoro-Jade B neuronal degeneration and Hematoxylin-eosin staining were measured 25 h after KA.

RESULTS

PET data evaluated at 2 h showed hyper-uptake of [¹⁸F]FDG in the control group, which was decreased by DDS. At 25 h, hypo-uptake was observed in the control group and higher values due to DDS effect. EEG spectral power was increased 2 h after KA administration in the control group during the generalized tonic-clonic seizures, which was reversed by DDS, correlated with [¹⁸F]FDG-PET uptake changes. The values of caspases-8 activity decreased 48 and 43 % vs control group in the groups treated with DDS (12.5 y 25 mg/kg respectively), likewise; caspase-3 activity diminished by 57 and 53 %. Fewer degenerated neurons were observed due to DDS treatments.

CONCLUSIONS

This study pinpoints the anticonvulsant therapeutic potential of DDS. Given its safety and effectiveness, DDS may be a viable alternative for patients with drug-resistant epilepsy.

Hypersensitivity reactions to non beta-lactam antimicrobial agents, a statement of the WAO special committee on drug allergy

Antibiotics are used extensively in the treatment of various infections. Consequently, they can be considered among the most important agents involved in adverse reactions to drugs, including both allergic and non-allergic drug hypersensitivity [J Allergy Clin Immunol 113:832–836, 2004]. Most studies published to date deal mainly with reactions to the beta-lactam group, and information on hypersensitivity to each of the other antimicrobial agents is scarce. The present document has been produced by the Special Committee on Drug Allergy of the World Allergy Organization to present the most relevant information on the incidence, clinical manifestations, diagnosis, possible mechanisms, and management of hypersensitivity reactions to non beta-lactam antimicrobials for use by practitioners worldwide.

Safety and tolerability of dapsone for the treatment of patients with drug-resistant, partial-onset seizures: an open-label trial

Dapsone has shown anti-convulsive properties in animal models of epilepsy. In the present study, we tested the safety and tolerability of dapsone as adjunctive therapy in adult patients with drug-resistant partial-onset seizures. Twenty-two adult patients with drug-resistant partial-onset seizures were included. After a 3-month baseline period, patients received dapsone 100 mg per day, for a 3-month evaluation period. Plasma concentrations of anti-epileptic drugs (AEDs) did not significantly change during the study. No alteration of mean clinical laboratory values was observed. The reported adverse events were: mild methemoglobinemia (50%), headache (31.8%), paleness (27.3%) and somnolence (4.5%).Sixteen of 22 patients reduced their seizure frequency in more than 50% as a result of dapsone treatment. Three subjects remained seizure-free during the entire dapsone treatment period. This open-label study of adjunctive dapsone therapy at 100 mg/day suggests that dapsone is safe, and well-tolerated in adults with drug-resistant partial-onset seizures.

Peripheral Neuropathy Due to Leprosy

Leprosy, also known as Hansen's disease, remains a significant cause of disability worldwide. After the introduction of treatment regimens using a combination of dapsone, rifampin, and clofazimine, the prevalence of the disease declined from 5.4 million registered cases in 1985 to less than a million in 1999. However, the incidence of new cases has remained stable due at least in part to a population of asymptomatic carriers. Immune-mediated nerve damage can occur during treatment or after treatment is completed and mandates continued careful follow-up of patients. Patient education and rehabilitation are crucial aspects of disease management and prevention of disability. In the US, patient care and medications are available through regional clinics sponsored by the Department of Health and Human Services. Patients should contact the National Hansen's Disease Program at 1770 Physician's Park Drive, Baton Rouge, Louisiana 70816; 1-800-642-2477.

Preliminary evaluation of the toxicity and efficacy of novel 2,4-diamino-5-benzylpyrimidine-sulphone derivatives using rat and human tissues in vitro

Four novel combined dapsone and trimethoprim analogues, K-120, K-150, K-138 and DRS-506, have been compared with dapsone in their methaemoglobin forming abilities as well as their anti-inflammatory properties using rat and human tissues in vitro. All four compounds formed consistently less methaemoglobin compared with dapsone in both the rat and human microsomes. Using human microsomes from five livers, K-120 was significantly less toxic than the other analogues in three of the five livers (P < 0.01). DRS-506 and K-138 both inhibited the human neutrophil respiratory burst to a significantly greater degree compared with dapsone at 0.5 mM (P < 0.01), while K-120 and K-150 showed no significant effect at 0.5 mM. At 1 mM, DRS-506, K-120 and K-138 were more potent than dapsone (P < 0.01), although K-150 appeared to increase the neutrophil activation. All four analogues caused a significant reduction in neutrophil adhesion to human umbilical vein cells at 0.1 mM. In view of its efficacy and low toxicity, K-120 shows considerable promise for future clinical evaluation.