Miscellaneous treatments: thalidomide, potassium iodide, levamisole, clofazimine, colchicine, and D-penicillamine

Sweet Syndrome and Neutrophilic Dermatosis of the Dorsal Hands

Sweet syndrome is a rare cutaneous condition with a broad clinical differential diagnosis. It can be classified into 3 subtypes: classic, malignancy-associated, and drug-induced. There are numerous associated disorders and provoking medications. Uncommonly, it can present as a multiorgan disease and cause significant morbidity. Systemic corticosteroids are the gold standard of treatment and yield rapid improvements in both lesions and symptoms. Nonsteroidal therapies may be effective alternatives, although high-quality comparative data are lacking. Some treatments for Sweet syndrome have paradoxically been implicated in the induction of disease.

Antibiotics with Antiviral and Anti-Inflammatory Potential Against Covid-19: A Review

In Covid-19 cases, elderly patients in long-term care facilities, children younger than five years with moderate symptoms, and patients admitted to ICU or with comorbidities are at a high risk of coinfection, as suggested by the evidence. Thus, in these patients, antibiotic therapy based on empirical evidence is necessary. Finding appropriate antimicrobial agents, especially with antiviral and anti-inflammatory properties, is a promising approach to target the virus and its complications, hyper-inflammation, and microorganisms resulting in co-infection. Moreover, indiscriminate use of antibiotics can be accompanied by Clostridioides difficile colitis, the emergence of resistant microorganisms, and adverse drug reactions, particularly kidney damage and QT prolongation. Therefore, rational administration of efficient antibiotics is an important issue. The main objective of the present review is to provide a summary of antibiotics with possible antiviral activity against SARS-CoV-2 and anti-immunomodulatory effects to guide scientists for further research. Besides, the findings can help health professionals in the rational prescription of antibiotics in Covid-19 patients with a high risk of co-infection.

Potassium iodide in refractory, recurrent pediatric Sweet syndrome: Guidance in dosing and monitoring

We describe a 5-month-old boy with clinical and histopathologic presentation of Sweet syndrome. He responded to systemic corticosteroids, with multiple flares on tapering; potassium iodide was added, which provided complete resolution of Sweet syndrome. Potassium iodide has been used in only a few cases, and no standard dosage has been established in children. We discuss calculation of a pediatric dosage for potassium iodide in Sweet syndrome.

In vitro interaction of some drug combinations to inhibit rapidly growing mycobacteria isolates from cats and dogs and these isolates' susceptibility to cefovecin and clofazimine

OBJECTIVES

To investigate whether selected drug combinations used to treat rapidly growing mycobacteria (RGM) have drug-drug interactions that affect efficacy and to investigate each isolate's susceptibility to cefovecin and clofazimine, individually.

DESIGN

In vitro susceptibility testing of bacterial isolates.

METHODS

Initially, five feline isolates and one canine isolate from both Mycobacterium fortuitum and M. smegmatis clusters (n = 12) underwent microbroth susceptibility testing to individual drugs to establish minimum inhibitory concentrations (MIC) of cefovecin, ciprofloxacin, clarithromycin, clofazimine, doxycycline, enrofloxacin, trimethoprim and sulfanilamide (the latter two as a combination). Checkerboard assays were then performed for susceptible M. smegmatis isolates for the following combinations: clarithromycin (one isolate only) versus enrofloxacin, clarithromycin vs doxycycline, clarithromycin vs trimethoprim/sulfanilamide; enrofloxacin vs doxycycline (six isolates); enrofloxacin vs trimethoprim/sulfanilamide (six isolates). Susceptible M. fortuitum isolates were tested against enrofloxacin versus doxycycline (four isolates only).

RESULTS

All six M. fortuitum isolates were susceptible to enrofloxacin, but only four of six were susceptible to doxycycline. All six M. smegmatis isolates were susceptible to doxycycline, enrofloxacin and trimethoprim/sulfanilamide. A single isolate from the 12, a M. smegmatis isolate, was susceptible to clarithromycin. The fractional inhibitory concentration of each drug ranged from 0.64 to 1.84, indicating that neither synergism nor antagonism was evident. All 12 isolates were resistant to cefovecin. The clofazimine MIC50 to inhibit isolate growth was approximately 3.3 μg/mL for both strains.

CONCLUSION

Drugs commonly used for treatment of RGM, when tested as combinations, do not appear to antagonise one another in vitro. Cefovecin is not efficacious for treatment of RGM infections.

Tetramisole and Levamisole Suppress Neuronal Activity Independently from Their Inhibitory Action on Tissue Non-specific Alkaline Phosphatase in Mouse Cortex

Tissue non-specific alkaline phosphatase (TNAP) may be involved in the synthesis of GABA and adenosine, which are the main inhibitory neurotransmitters in cortex. We explored this putative TNAP function through electrophysiological recording (local field potential ) in slices of mouse somatosensory cortex maintained in vitro. We used tetramisole, a well documented TNAP inhibitor, to block TNAP activity. We expected that inhibiting TNAP with tetramisole would lead to an increase of neuronal response amplitude, owing to a diminished availability of GABA and/or adenosine. Instead, we found that tetramisole reduced neuronal response amplitude in a dose-dependent manner. Tetramisole also decreased axonal conduction velocity. Levamisole had identical effects. Several control experiments demonstrated that these actions of tetramisole were independent from this compound acting on TNAP. In particular, tetramisole effects were not stereo-specific and they were not mimicked by another inhibitor of TNAP, MLS-0038949. The decrease of axonal conduction velocity and preliminary intracellular data suggest that tetramisole blocks voltage-dependent sodium channels. Our results imply that levamisole or tetramisole should not be used with the sole purpose of inhibiting TNAP in living excitable cells as it will also block all processes that are activity-dependent. Our data and a review of the literature indicate that tetramisole may have at least four different targets in the nervous system. We discuss these results with respect to the neurological side effects that were observed when levamisole and tetramisole were used for medical purposes, and that may recur nowadays due to the recent use of levamisole and tetramisole as cocaine adulterants.

Oleoma: rare complication of mesotherapy for cellulite

BACKGROUND

Mesotherapy or intradermotherapy is used as a cosmetic procedure for many purposes, among them for cellulite.

METHODS

We report a case of oleoma on the thighs and buttocks that appeared two years after the injection of an unknown substance for improvement of cellulite.

RESULTS

Lesions and associated pruritus resolved with colchicine, leaving depressed scars.

CONCLUSIONS

Serious and peer-reviewed investigations must be performed to certify the efficacy and safety of this procedure.

Clofazimine analogs with efficacy against experimental tuberculosis and reduced potential for accumulation

The global tuberculosis crisis urgently demands new, efficacious, orally available drugs with the potential to shorten and simplify the long and complex treatments for drug-sensitive and drug-resistant disease. Clofazimine, a riminophenazine used for many years to treat leprosy, demonstrates efficacy in animal models of tuberculosis via a novel mode of action. However, clofazimine's physicochemical and pharmacokinetic properties contribute to side effects that limit its use; in particular, an extremely long half-life and propensity for tissue accumulation together with clofazimine's dye properties leads to unwelcome skin discoloration. We recently conducted a systematic structure-activity study of more than 500 riminophenazine analogs for anti-Mycobacterium tuberculosis activity. We describe here the characteristics of 12 prioritized compounds in more detail. The new riminophenazine analogs demonstrated enhanced in vitro activity compared to clofazimine against replicating M. tuberculosis H37Rv, as well as panels of drug-sensitive and drug-resistant clinical isolates. The new compounds demonstrate at least equivalent activity compared to clofazimine against intracellular M. tuberculosis and, in addition, most of them were active against nonreplicating M. tuberculosis. Eleven of these more water-soluble riminophenazine analogs possess shorter half-lives than clofazimine when dosed orally to mice, suggesting that they may accumulate less. Most importantly, the nine compounds that progressed to efficacy testing demonstrated inhibition of bacterial growth in the lungs that is superior to the activity of an equivalent dose of clofazimine when administered orally for 20 days in a murine model of acute tuberculosis. The efficacy of these compounds, along with their decreased potential for accumulation and therefore perhaps also for tissue discoloration, warrants further study.

Reduction of clofazimine by mycobacterial type 2 NADH:quinone oxidoreductase: a pathway for the generation of bactericidal levels of reactive oxygen species

The mechanism of action of clofazimine (CFZ), an antimycobacterial drug with a long history, is not well understood. The present study describes a redox cycling pathway that involves the enzymatic reduction of CFZ by NDH-2, the primary respiratory chain NADH:quinone oxidoreductase of mycobacteria and nonenzymatic oxidation of reduced CFZ by O(2) yielding CFZ and reactive oxygen species (ROS). This pathway was demonstrated using isolated membranes and purified recombinant NDH-2. The reduction and oxidation of CFZ was measured spectrally, and the production of ROS was measured using a coupled assay system with Amplex Red. Supporting the ROS-based killing mechanism, bacteria grown in the presence of antioxidants are more resistant to CFZ. CFZ-mediated increase in NADH oxidation and ROS production were not observed in membranes from three different Gram-negative bacteria but was observed in Staphylococcus aureus and Saccharomyces cerevisiae, which is consistent with the known antimicrobial specificity of CFZ. A more soluble analog of CFZ, KS6, was synthesized and was shown to have the same activities as CFZ. These studies describe a pathway for a continuous and high rate of reactive oxygen species production in Mycobacterium smegmatis treated with CFZ and a CFZ analog as well as evidence that cell death produced by these agents are related to the production of these radical species.

Taming the neutrophil: calcium clearance and influx mechanisms as novel targets for pharmacological control

Neutrophils are relatively insensitive to the anti-inflammatory actions of conventional chemotherapeutic agents, including corticosteroids, emphasizing the requirement for novel pharmacological strategies to control the potentially harmful proinflammatory activities of these cells. In the case of commonly-occurring inflammatory diseases of the airways, the neutrophil is the primary mediator of inflammation in conditions such as chronic obstructive pulmonary disease, cystic fibrosis, acute respiratory distress syndrome, bronchiectasis and non-eosinophilic bronchial asthma. Recent insights into the mechanisms utilized by neutrophils to restore Ca(2+) homeostasis following activation with Ca(2+)-mobilizing, proinflammatory stimuli have facilitated the identification of novel targets for anti-inflammatory chemotherapy in these cells. The most amenable of these from a chemotherapeutic perspective, is the cyclic AMP-dependent protein kinase-modulated endomembrane Ca(2+)-ATPase which promotes clearance of the cation from the cytosol of activated neutrophils. Second generation type 4 phosphodiesterase inhibitors and adenosine receptor agonists operative at the level of subtype A2A adenosine receptors, which are currently undergoing clinical and preclinical assessment respectively, hold promise as pharmacologic modulators during the restoration of Ca(2+) homeostasis. If this promise is realized, it may result in novel chemotherapeutic strategies for the control of hyperacute and chronic inflammatory conditions in which neutrophils are primary offenders. Alternative, potential future targets include the Na(+), Ca(2+)-exchanger and store-operated Ca(2+) channels, which cooperate in the refilling of intracellular Ca(2+) stores.

Levamisole in dermatology : a review

Levamisole, an anthelmintic agent with a wide range of immunomodulatory actions, has been used successfully as monotherapy and an adjunct to treatment in a variety of diseases. Since 1990, combination therapy of levamisole and fluorouracil has played an important role in the treatment of resected Dukes stage C adenocarcinoma of the colon. Because of its immunomodulating effects levamisole has been used in a wide range of diseases with and without success. In dermatologic disease levamisole has been successfully used in the treatment of parasitic, viral and bacterial infections including leprosy, collagen vascular diseases, inflammatory skin diseases and children with impaired immune a variety of reasons. It has also been used in combination with other drugs for treating a number of dermatologic disorders, e.g. in combination with cimetidine for treating recalcitrant warts, with prednisolone for treating lichen planus, erythema multiforme and aphthous ulcers of the mouth. Adverse affects of levamisole are mild and infrequent and include rash, nausea, abdominal cramps, taste alteration, alopecia, arthralgia, and a flu-like syndrome. It can rarely cause agranulocytosis. More studies need to be undertaken to study the full potential of levamisole in dermatologic diseases.

The anthelmintic levamisole is an allosteric modulator of human neuronal nicotinic acetylcholine receptors

L-[-]-2,3,5,6-Tetrahydro-6-phenylimidazo[2,1b]-thiazole hydrochloride (levamisole) is an anthelmintic that targets the nicotinic acetylcholine receptors of parasitic nematodes. We report here the effects of levamisole on human neuronal alpha 3 beta 2 and alpha 3 beta 4 nicotinic receptors, heterologously expressed in Xenopus oocytes and studied with the voltage clamp method. Applied alone, levamisole was a very weak partial agonist for the two subunit combinations. When co-applied with acetylcholine, micromolar concentrations of levamisole potentiated responses, while millimolar concentrations inhibited them; these effects were complex functions of both acetylcholine and levamisole concentrations. The differences in the levamisole effects on the two receptor combinations suggest that the effects are mediated by the beta subunit. Several combinations of agonist and anthelmintic gave the dual potentiation/inhibition behavior, suggesting that the modulatory effects are general. Levamisole inhibition showed macroscopic characteristics of open channel block. Several results led us to conclude that levamisole potentiation occurs through noncompetitive binding to the receptor. We propose pseudo-site binding for noncompetitive potentiation by levamisole.

Sweet's syndrome: a review of current treatment options

Sweet's syndrome was originally described in 1964 by Dr Robert Douglas Sweet as an 'acute febrile neutrophilic dermatosis'. The syndrome is characterized by pyrexia, elevated neutrophil count, painful red papules, nodules, plaques (which may be recurrent) and an infiltrate consisting predominantly of mature neutrophils that are diffusely distributed in the upper dermis. In addition to skin and mucosal lesions, Sweet's syndrome can also present with extra-cutaneous manifestations. Sweet's syndrome can be classified based upon the clinical setting in which it occurs: classical or idiopathic Sweet's syndrome, malignancy-associated Sweet's syndrome and drug-induced Sweet's syndrome. Systemic corticosteroids have been considered the 'gold standard' for the treatment of patients with Sweet's syndrome; in addition, treatment with topical and/or intralesional corticosteroids may be effective as either monotherapy or adjuvant therapy. However, spontaneous resolution of the symptoms and lesions has occurred in several patients with Sweet's syndrome for whom disease-specific therapeutic intervention was not initiated and in some of the patients with drug-induced Sweet's syndrome after withdrawal of the dermatosis-causing medication. Oral therapy with either potassium iodide or colchicine typically results in rapid resolution of Sweet's syndrome symptoms and lesions; therefore, in patients with Sweet's syndrome who have a potential systemic infection or in whom corticosteroids are contraindicated, it is reasonable to initiate treatment with these agents as a first-line therapy. Indomethacin, clofazimine, dapsone, and cyclosporine have also been effective therapeutic agents for managing Sweet's syndrome. However, indomethacin and clofazimine appear less effective than corticosteroids, potassium iodide, and colchicine. Appropriate initial and follow-up laboratory monitoring is necessary when treating with either dapsone or cyclosporine because of the potential for severe adverse drug-associated effects. Systemic antibacterials with activity against Staphylococcus aureus frequently result in partial improvement of Sweet's syndrome lesions when they are impetiginized or secondarily infected. In some patients with dermatosis-associated bacterial infections, organism-sensitive specific systemic antibacterials have been helpful in the management of their Sweet's syndrome. Although patients with hematologic malignancy-associated Sweet's syndrome often receive cytotoxic chemotherapy agents and antimetabolic drugs for the treatment of their underlying disorder, these agents are seldom used solely for the management of the symptoms and lesions of Sweet's syndrome. The treatment of patients with Sweet's syndrome with either etretinate or interferon-alpha have been reported as single case reports; both patients had improvement of not only their Sweet's syndrome lesions, but also their associated hematologic disorder.