Combination Of Rifampicin Research Articles

In vitro additive effects of dalbavancin and rifampicin against biofilm of Staphylococcus aureus

Dalbavancin is a novel glycopeptide antibiotic approved for the treatment of acute bacterial skin and skin structure infections (ABSSSIs). It is characterized by a potent activity against numerous Gram-positive pathogens, a long elimination half-life and a favorable safety profile. Most recently, its application for the treatment of periprosthetic joint infections (PJIs) was introduced. The aim of this study was to proof our hypothesis, that dalbavancin shows superior efficacy against staphylococcal biofilms on polyethylene (PE) disk devices compared with vancomycin and additive behavior in combination with rifampicin. Staphylococcus aureus biofilms were formed on PE disk devices for 96 h and subsequently treated with dalbavancin, vancomycin, rifampicin and dalbavancin-rifampicin combination at different concentrations. Quantification of antibacterial activity was determined by counting colony forming units (CFU/ml) after sonification of the PE, serial dilution of the bacterial suspension and plating on agar-plates. Biofilms were additionally life/dead-stained and visualized using fluorescence microscopy. Dalbavancin presented superior anti-biofilm activity compared to vancomycin. Additive effects of the combination dalbavancin and rifampicin were registered. Dalbavancin combined with rifampicin presents promising anti-biofilm activity characteristics in vitro. Further in vivo studies are necessary to establish recommendations for the general use of dalbavancin in the treatment of PJIs.

Impact of rifampicin on the pharmacokinetics of clarithromycin and 14-hydroxy clarithromycin in patients with multidrug combination therapy for pulmonary Mycobacterium avium complex infection

IntroductionClarithromycin (CAM), ethambutol (EB), and rifampicin (RFP) combination therapy is used to treat pulmonary Mycobacterium avium complex (MAC) infection; however, serum CAM concentration decreases due to RFP-mediated induction of CYP3A activity. Therefore, we investigated the pharmacokinetics of CAM, 14-hydroxy clarithromycin (14-OH CAM), EB, and RFP in patients receiving this three-drug combination therapy. MethodsCAM monotherapy was started, EB was added 2 weeks later, and RFP was added 2 weeks after that. Serum CAM, 14-OH CAM, EB, and RFP concentrations were measured before and at 2, 4, 6, and 12 or 24 h after administration on days 14, 28, and 42, and pharmacokinetic parameters were calculated. ResultsMedian area under the curve (AUC) of CAM decreased by 92.1% from 0 to 12 h after concomitant administration of RFP compared with CAM monotherapy [1.7 (interquartile range [IQR], 1.4–1.8) μg·h/mL vs. 21.5 (IQR, 17.7–32.3) μg·h/mL, respectively]. In contrast, median AUC of 14-OH CAM was not significantly different between concomitant administration of RFP [9.1 (IQR, 7.9–10.9) μg·h/mL] and CAM monotherapy [8.2 (IQR, 6.3–9.3) μg·h/mL]. AUCs of CAM and 14-OH CAM did not change in CAM+EB combination therapy. ConclusionsWhen RFP is combined with CAM in the treatment of pulmonary MAC infection, the blood concentration of CAM significantly decreased and that of the active metabolite 14-OH CAM increased, but not significantly. Our results suggest that combination therapy with CAM and RFP needs to be reconsidered and may require dose modification in the treatment of pulmonary MAC infection.

Optimizing Dosing and Fixed-Dose Combinations of Rifampicin, Isoniazid, and Pyrazinamide in Pediatric Patients With Tuberculosis: A Prospective Population Pharmacokinetic Study.

In 2010, the World Health Organization (WHO) revised dosing guidelines for treatment of childhood tuberculosis. Our aim was to investigate first-line antituberculosis drug exposures under these guidelines, explore dose optimization using the current dispersible fixed-dose combination (FDC) tablet of rifampicin/isoniazid/pyrazinamide; 75/50/150mg, and suggest a new FDC with revised weight bands. Children with drug-susceptible tuberculosis in Malawi and South Africa underwent pharmacokinetic sampling while receiving first-line tuberculosis drugs as single formulations according the 2010 WHO recommended doses. Nonlinear mixed-effects modeling and simulation was used to design the optimal FDC and weight-band dosing strategy for achieving the pharmacokinetic targets based on literature-derived adult AUC0-24h for rifampicin (38.7-72.9), isoniazid (11.6-26.3), and pyrazinamide (233-429 mg ∙ h/L). In total, 180 children (42% female; 13.9% living with human immunodeficiency virus [HIV]; median [range] age 1.9 [0.22-12] years; weight 10.7 [3.20-28.8] kg) were administered 1, 2, 3, or 4 FDC tablets (rifampicin/isoniazid/pyrazinamide 75/50/150mg) daily for 4-8, 8-12, 12-16, and 16-25kg weight bands, respectively. Rifampicin exposure (for weight and age) was up to 50% lower than in adults. Increasing the tablet number resulted in adequate rifampicin but relatively high isoniazid and pyrazinamide exposures. Administering 1, 2, 3, or 4 optimized FDC tablets (rifampicin/isoniazid/pyrazinamide 120/35/130mg) to children < 6, 6-13, 13-20. and 20-25kg, and 0.5 tablet in < 3-month-olds with immature metabolism, improved exposures to all 3 drugs. Current pediatric FDC doses resulted in low rifampicin exposures. Optimal dosing of all drugs cannot be achieved with the current FDCs. We propose a new FDC formulation and revised weight bands.

Overview: Development of Drugs Against Mycobacterium ulcerans.

For many years, wide margin surgical excision of Buruli ulcer lesions has been the main approach for the treatment of Mycobacterium ulcerans disease. The WHO now recommends an eight-week course of oral antibiotics with a combination of rifampicin and clarithromycin in Africa. However, disease management is complicated by social stigma, lack of awareness, and limited access to healthcare facilities, resulting in underreporting and frequently late initiation of medical treatment. Inadequate initial treatment can drive permanent disabilities and also limited compliance to the eight-week therapy is a limitation. Therefore, search for a faster and more simple treatment modality is ongoing, focusing primarily on the testing of new tuberculosis drug candidates for the treatment of M. ulcerans disease.

064 Short-term intravenous clindamycin accelerates the benefit of oral clindamycin-rifampicin treatment in hidradenitis suppurativa (HS)

A 10-to-12-week course of combined clindamycin/rifampicin or tetracyclines are the first-line medical treatment for moderate-to-severe HS. A recent multicenter European study revealed significant efficacy of oral clindamycin/rifampicin and tetracyclines without differences between them, independently of baseline HS severity. Our study explored the efficacy of a treatment induction with a 5-day loading dose of i.v. clindamycin (3x600 mg/d) prior to the oral clindamycin/ rifampicin combination, in 95 consecutive, previous treatment-naive adult HS patients.

In vitro Synergism of Six Antituberculosis Agents Against Drug-Resistant Mycobacterium tuberculosis Isolated from Retreatment Tuberculosis Patients

BackgroundRetreatment tuberculosis (TB) has become a major source of drug-resistant TB. In contrast to the combination of isoniazid (INH) and rifampicin (RIF), that of pasiniazid (Pa) and rifabutin (RFB) or rifapentine (RFP) appears to have better activity in vitro against drug-resistant Mycobacterium tuberculosis (MTB), especially when combined with moxifloxacin (MXF). However, there has been limited study of potential synergism among Pa, RFB, RFP, and MXF, or simultaneous comparison with the standard INH and RIF combination.MethodsIn vitro synergism of four two-drug combinations (INH and RIF, Pa and RFB, Pa and RFP, MXF and Pa) and two three-drug combinations (MXF and Pa combined with RFB or RFP) was evaluated against 90 drug-resistant MTB strains isolated from retreatment TB patients by the checkerboard method. The fractional inhibitory concentration index (FICI) was calculated for each combination.ResultsThe synergistic activity of the combination of Pa with RFB or RFP was higher than that of INH and RIF or MXF and Pa, and the synergistic activity of Pa in combination with RFP was even higher than that of RFB, although RFP yielded an MIC90 of 64 mg/liter, higher than that of RFB of 8 mg/liter against 90 drug-resistant MTB strains. Meanwhile, for three-drug combinations, the synergistic effects of MXF and Pa combined with RFB or RFP were similar. Further stratification analysis showed that, for XDR-MTB strains, the synergistic effect of the Pa and RFP combination was also better than those of other two-drug combinations.ConclusionThe combination of Pa with RFP shows better in vitro synergism than Pa with RFB and standard INH with RIF combinations, which can provide a reference for new regimens for retreatment TB patients.

No increased incidence of Clostridium difficile infection among patients with hidradenitis suppurativa treated with systemic clindamycin

No increased incidence of Clostridium difficile infection among patients with hidradenitis suppurativa treated with systemic clindamycin

Potential Role of CXCL10 in Monitoring Response to Treatment in Leprosy Patients.

The treatment of multibacillary cases of leprosy with multidrug therapy (MDT) comprises 12 doses of a combination of rifampicin, dapsone and clofazimine. Previous studies have described the immunological phenotypic pattern in skin lesions in multibacillary patients. Here, we evaluated the effect of MDT on skin cell phenotype and on the Mycobacterium leprae-specific immune response. An analysis of skin cell phenotype demonstrated a significant decrease in MRS1 (SR-A), CXCL10 (IP-10) and IFNG (IFN-γ) gene and protein expression after MDT release. Patients were randomized according to whether they experienced a reduction in bacillary load after MDT. A reduction in CXCL10 (IP-10) in sera was associated with the absence of a reduction in the bacillary load at release. Although IFN-γ production in response to M. leprae was not affected by MDT, CXCL10 (IP-10) levels in response to M. leprae increased in cells from patients who experienced a reduction in bacillary load after treatment. Together, our results suggest that CXCL10 (IP-10) may be a good marker for monitoring treatment efficacy in multibacillary patients.

3D Printed Housing Devices for Segregated Compartmental Delivery of Oral Fixed-Dose Anti-Tubercular Drugs Adopting Print and Fill Strategy.

World Health Organization (WHO) recommends the use of first-line anti-tuberculosis drugs, that is, rifampicin (RIF) and isoniazid (INH) fixed-dose combination (FDC) therapies in tuberculosis (TB) disease. The absorption of RIF from an FDC incorporates INH, and it is significantly compromised due to its reaction with INH, resulting in a severe loss of RIF under gastric stomach pH condition. Such reduction in the dose of both drugs from FDC formulations has been alleged to be one of the chief obstacles in effective TB treatment. This emphasizes a need to develop suitable cutting-edge advanced bioengineered delivery devices that can attenuate this severe problem to mitigate this chief obstacle. Therefore, we designed, prototyped, and characterized bioengineered 3D printed housing devices in the form of printed tablets adopting print and fill strategy for segregated compartmental delivery of RIF into the intestine (to avoid stomach gastric pH induced chemical degradation as alone and FDC) and INH into the stomach (no degradation observed as alone and FDC in stomach gastric pH conditions) for the desired treatment outcome against TB. Prepared 3D printed housings showed almost zero friability, enough hardness along weight variations <±3.0%. Different thermal and morphological analyses confirmed the insignificant changes in the nature of the polymer as before and after printing. The in vitro release for INH from polyvinyl alcohol mediated 3D printed housings showed almost 100% release within 2.5 h in acidic medium, whereas poly-lactic acid (PLA) mediated 3D printed housings continued to release RIF above 70% in the presence of physiological enzymes in alkaline medium for 432 h. The in vivo bioavailability assessment correlated with in vitro dissolution behavior for INH and RIF, whereas RIF did not release from 3D printed PLA housings in vivo.

A Strong Synergy Between the Thiopeptide Bacteriocin Micrococcin P1 and Rifampicin Against MRSA in a Murine Skin Infection Model.

Antibiotic-resistant bacterial pathogens have become a serious threat worldwide. One of these pathogens is methicillin-resistant Staphylococcus aureus (MRSA), a major cause of skin and soft tissue infections. In this study we identified a strain of Staphylococcus equorum producing a substance with high antimicrobial activity against many Gram-positive bacteria, including MRSA. By mass spectrometry and whole genome sequencing the antimicrobial substance was identified as the thiopeptide bacteriocin micrococcin P1 (MP1). Based on its properties we developed a one-step purification protocol resulting in high yield (15 mg/L) and high purity (98%) of MP1. For shorter incubation times (5-7 h) MP1 was very potent against MRSA but the inhibitory effect was overshadowed by resistance development during longer incubation time (24h or more). To overcome this problem a synergy study was performed with a number of commercially available antibiotics. Among the antibiotics tested, the combination of MP1 and rifampicin gave the best synergistic effect, with MIC values 25 and 60 times lower than for the individual drugs, respectively. To assess the therapeutic potential of the MP1-rifampicin combination, we used a murine skin infection model based on the use of the multidrug-resistant luciferase-tagged MRSA strain Xen31. As expected, neither of the single antimicrobials (MP1 or rifampicin) could eradicate Xen31 from the wounds. By contrary, the MP1-rifampicin combination was efficient not only to eradicate but also to prevent the recurrence of Xen31 infection. Furthermore, compared to fucidin cream, which is commonly used in skin infection treatments, MP1-rifampicin combination was superior in terms of preventing resistance development. Our results show that combining MP1, and probably other thiopeptides, with antibiotics can be a promising strategy to treat SSTIs caused by MRSA and likely many other Gram-positive bacteria.

Giant Subcutaneous Granuloma Annulare

Subcutaneous granuloma annulare is an uncommon, benign self-limiting cutaneous disease, almost exclusively seen in young children. We report a case of 31-year-old male patient, presented with asymptomatic firm plaques over the left lateral malleoli and dorsum of the feet. Histopathological examination was done to confirm the diagnosis and the lesions responded well to monthly doses of the combination of rifampicin, ofloxacin, minocycline (ROM) therapy and intralesional steroid therapy. This case is reported for its unusual presentation of very large plaque in an adult male and its resolution after combined ROM and intralesional steroid therapy.

Adverse Drug Reactions Monitoring in Patients on Antitubercular Treatment in Tertiary Care Hospital, Mandya

Background: Tuberculosis is one of the major public health concerns in India. Treatment of tuberculosis need multidrug combinations, which is associated with increased incidence of adverse drug reactions (ADRs). Hence there is a need of active monitoring for adverse effects in patients who are on antitubercular treatment (ATT). Objectives: To study the pattern of ADRs caused by antitubercular drugs and to assess causality, severity and predisposing factors. Methodology: A prospective observational study was conducted for 6 months in tertiary care hospital of Mandya. A total of 74 patients of tuberculosis who experienced ADRs were included in the study after obtaining informed consent. Their demographic, treatment and ADR data were collected and analysed. Causality was assessed using WHO scale and Naranjo’s algorithm, whereas severity was assessed by Modified Hartwig and Siegel scale. Results: Among 74 patients, 55(74.32%) were males and 19 (25.67%) were females. A total of 86 ADRs were recorded amongst 74 patients, as 11 patients experienced two ADRs. During intensive and continuation phase of treatment, 65 (87.63%) and 9 (12.16%)patients experienced ADRs respectively. Gastrointestinal side effects and hepatotoxicity were the most frequently observed ADRs with 23 (26.7%) each, followed by pruritus and rashes in 18 (20.93%) patients.63.51% of ADRs had an association with fixed dose combination (FDC) of isoniazid, rifampicin, pyrazinamide and ethambutol. As per WHO scale and Naranjo’s algorithm majority of ADRs were probable with 44 (59.45%) and 58 (78.37%) respectively. Most of the ADRs belonged to mild (67.56%) category as per Modified Hartwig and Siegel scale. Conclusion: ADRs induced by ATT are common. Hence counselling of patients regarding their life style along with early detection and management will minimize the occurrence of ADRs and improvethe adherence to treatment.

Effect of Alcornea cordifolia Aqueous and Methanolic Leaf Extracts against Antituberculosis Drugs Induced Liver Damage in Rats

The hepatoprotective properties of Alchornea cordifolia, a medicinal plant was studied in hepatotoxicity induced animal model with a high dose of paracetamol or carbon tetrachloride. Knowing that antituberculosis drugs also represent a risk factor for hepatotoxicity, could A. cordifolia play a key role to limit their hepatotoxicity? The objective of this study was to assess the histological changes of antituberculosis drugs in rat livers and their evolution after administration of an aqueous and a methanolic leaf extracts of A. cordifolia and therefore estimate their polyphenol and flavonoid contents. Rats were divided into three (3) groups: group 1 was treated with isoniazid; group 2 received the combination of isoniazid and rifampicin and group 3 was given the combination of isoniazid, rifampicin and pyraziamide. For each group of rats, the hepatotoxicant was either administered alone or two hours before administration of an aqueous (200, 400, or 800 mg/kg) or a methanolic (200, 400, or 800 mg/kg) leaf extracts of A. cordifolia each day for 10 days. Animals were sacrificed on day 11 and their livers removed for histolopathological analysis. In addition, total polyphenol and flavonoid contents were estimated in both extracts. Antituberculosis drug combinations caused peliosis lesions, steatosis and hepatocyte necrosis. The liver histology of rats that received extracts after administration of antituberculosis drug combinations showed the ability of extracts to annihilate or alleviate hepatocellular damage caused by such drugs. The methanolic extract, richer in total polyphenols (0.55 ± 0.02 mg EGA) than the aqueous extract (0.35 ± 0.01 mg EGA) demonstrated a greater hepatoprotective effect. Thus, according to liver histological analysis, the aqueous and methanolic leaf extracts of A. cordifolia could attenuate the hepatotoxicity induced by antituberculosis drugs in rats.

The Characteristics, Prevalence, and Risk Factors of Drug-Induced Liver Injury Among Brucellosis Inpatients in Xinjiang, China.

Background: We investigated the prevalence, demographic and clinical features, and risk factors associated with drug-induced liver injury (DILI) during the treatment of brucellosis inpatients in a retrospective study. Methods: We collected the clinical data of 782 brucellosis inpatients admitted at the Shawan County People’s Hospital, Xinjiang, from 2015–2019. All cases were re-evaluated using the international consensus of DILI criteria and RUCAM rating scale. 71 patients were confirmed as DILI cases and compared with 523 other patients with normal liver function. Results: It was indicated that DILI occurred with a prevalence of about 9.08% among brucellosis inpatients receiving drug therapy. Hepatocellular injury was the most common type of DILI (61.97%, 95% confidence interval [CI] 50.34–72.37), followed by mixed (23.94%, 95% CI 15.52–35.04) and cholestatic types (14.08%, 95% CI 7.83–24.02). In addition, 13.64% of the hepatocellular DILI cases fulfilled Hy’s law criteria and only two cases (2.82%) progressed to severe DILI. Most patients adopted the combination of rifampicin, antipyretic analgesics, anti-infective agents, and traditional Chinese medicine for the treatment of brucellosis, with all the 71 patients taking rifampicin as the drug of choice. Multivariable logistic regression analyses indicated that obesity, regular alcohol intake, and decreased serum albumin were the independent risk factors of DILI in patients with brucellosis after adjusting for gender, age, and ethnicity. Conclusion: DILI occurred in a minority of inpatients diagnosed with brucellosis receiving rifampicin-based therapeutic regimen. In addition, obesity, alcohol abuse, and decreased serum albumin were valuable predictors of the risk of DILI in patients with brucellosis.

Influence of the clindamycin administration route on the magnitude of clindamycin–rifampicin interaction: a prospective pharmacokinetic study

ObjectivesAn important clindamycin–rifampicin pharmacokinetic (PK) interaction has been reported, but the potential influence of the clindamycin administration route on that interaction is unknown. This prospective, observational, comparative PK study was undertaken to characterize and analyse the impact of the route, comparing the rifampicin enzyme-inductor effects on clindamycin clearance (CLclin) for oral versus intravenous (IV) administration. MethodsPatients with bone-and-joint infections (BJIs) were treated with clindamycin monotherapy (n = 20) or clindamycin–rifampicin combination therapy (n = 19). Patients received continuous IV clindamycin infusion for 2–6 weeks, followed by an oral regimen. Liquid chromatography–mass spectrometry was used to measure plasma clindamycin concentrations at the end of IV and after 2 weeks of oral treatment. The ratios of the mean CLclin for the combination and monotherapy groups were calculated for IV (Riv) and oral (Rpo) routes, with the final ratio, Rf = Rpo/Riv, representing the fold change of the rifampicin-inducing effect from the IV to the oral route. ResultsComparing monotherapy with combination-therapy groups, the former's median steady-state concentration was two-fold higher after IV administration (8.49 versus 3.82 mg/L, p < 0.001) and its median AUC0–8h was 12 times higher after oral intake (37.7 versus 3.1 mg.h/L, p < 0.001). Riv, Rpo and Rf were 2.68, 18.8 and 7.0 respectively. ConclusionThe magnitude of this interaction was markedly increased by oral intake, questioning the use of oral treatment for difficult-to-treat infections like BJIs. Nevertheless, the clindamycin–rifampicin combination seems possible provided that clindamycin is administered by continuous IV infusion.

Antibiotic Cross-linked Micelles with Reduced Toxicity for Multidrug-Resistant Bacterial Sepsis Treatment.

One potential approach to address the rising threat of antibiotic resistance is through novel formulations of established drugs. We designed antibiotic cross-linked micelles (ABC-micelles) by cross-linking the Pluronic F127 block copolymers with an antibiotic itself, via a novel one-pot synthesis in aqueous solution. ABC-micelles enhanced antibiotic encapsulation while also reducing systemic toxicity in mice. Using colistin, a hydrophilic, potent ″last-resort" antibiotic, ABC-micelle encapsulation yield was 80%, with good storage stability. ABC-micelles exhibited an improved safety profile, with a maximum tolerated dose of over 100 mg/kg colistin in mice, at least 16 times higher than the free drug. Colistin-induced nephrotoxicity and neurotoxicity were reduced in ABC-micelles by 10-50-fold. Despite reduced toxicity, ABC-micelles preserved bactericidal activity, and the clinically relevant combination of colistin and rifampicin (co-loaded in the micelles) showed a synergistic antimicrobial effect against antibiotic-resistant strains of Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. In a mouse model of sepsis, colistin ABC-micelles showed equivalent efficacy as free colistin but with a substantially higher therapeutic index. Microscopic single-cell imaging of bacteria revealed that ABC-micelles could kill bacteria in a more rapid manner with distinct cell membrane disruption, possibly reflecting a different antimicrobial mechanism from free colistin. This work shows the potential of drug cross-linked micelles as a new class of biomaterials formed from existing antibiotics and represents a new and generalized approach for formulating amine-containing drugs.

Molecular characteristics and in vitro effects of antimicrobial combinations on planktonic and biofilm forms of Elizabethkingia anophelis.

To investigate the in vitro activity of antibiotics against clinical Elizabethkingia anophelis isolates and to find a suitable antibiotic combination with synergistic effects to combat antibiotic-resistant E. anophelis and its associated biofilm. E. anophelis isolates were identified by 16S rRNA sequencing; 30 strains with different pulsotypes were identified and the MIC, antibiotic resistance mechanism, antibiotic combination activity and killing effects of antimicrobial agents on biofilms of these strains were determined. All E. anophelis isolates were susceptible to minocycline and cefoperazone/sulbactam (1:1). More than 90% of clinical isolates were susceptible to cefoperazone/sulbactam (1:0.5), piperacillin/tazobactam and rifampicin. Some novel mutations, such as gyrA G81D, parE D585N and parC P134T, that have never been reported before, were identified. The synergistic effect was most prominent for the combination of minocycline and rifampicin, with 93.3% of their FIC index values ≤0.5, and no antagonism was observed using the chequerboard method. This synergistic effect between minocycline and rifampicin was also observed using time-killing methods for clinical E. anophelis isolates at both normal inoculum and high inoculum. Twenty-nine isolates tested positive for biofilm formation. Minocycline remained active against biofilm-embedded and biofilm-released planktonic E. anophelis cells; however, the enhanced effect of minocycline by adding rifampicin was only observed at 24 h (not at 72 and 120 h). Although E. anophelis was resistant to many antibiotics and could exhibit biofilm formation, minocycline showed potent in vitro activity against this pathogen and its associated biofilm.

Fourteen-day PET/CT imaging to monitor drug combination activity in treated individuals with tuberculosis.

Early bactericidal activity studies monitor daily sputum bacterial counts in individuals with tuberculosis (TB) for 14 days during experimental drug treatment. The rate of change in sputum bacterial load over time provides an informative, but imperfect, estimate of drug activity and is considered a critical step in development of new TB drugs. In this clinical study, 160 participants with TB received isoniazid, pyrazinamide, or rifampicin, components of first-line chemotherapy, and moxifloxacin individually and in combination. In addition to standard bacterial enumeration in sputum, participants underwent 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography and computerized tomography ([18F]FDG-PET/CT) at the beginning and end of the 14-day drug treatment. Quantitating radiological responses to drug treatment provided comparative single and combination drug activity measures across lung lesion types that correlated more closely with established clinical outcomes when combined with sputum enumeration compared to sputum enumeration alone. Rifampicin and rifampicin-containing drug combinations were most effective in reducing both lung lesion volume measured by CT imaging and lesion-associated inflammation measured by PET imaging. Moxifloxacin was not superior to rifampicin in any measure by PET/CT imaging, consistent with its performance in recent phase 3 clinical trials. PET/CT imaging revealed synergy between isoniazid and pyrazinamide and demonstrated that the activity of pyrazinamide was limited to lung lesion, showing the highest FDG uptake during the first 2 weeks of drug treatment. [18F]FDG-PET/CT imaging may be useful for measuring the activity of single drugs and drug combinations during evaluation of potential new TB drug regimens before phase 3 trials.

The efficacy and tolerability of tetracyclines and clindamycin plus rifampicin for the treatment of hidradenitis suppurativa: Results of a prospective European cohort study

Tetracyclines and clindamycin plus rifampicin combination therapy are both considered first-line therapy in current hidradenitis suppurativa guidelines. However, evidence for their efficacy is drawn from small studies, often without validated outcomes. To assess the 12-week efficacy of oral tetracyclines and a combination of clindamycin and rifampicin. A prospective, international cohort study performed between October 2018 and August 2019. In total, 63.6% of the included 283 patients received oral tetracyclines, and 36.4% were treated with clindamycin and rifampicin. Both groups showed a significant decrease in International Hidradenitis Suppurativa Severity Score System from baseline (both P<.001). The Hidradenitis Suppurativa Clinical Response (HiSCR) was achieved in 40.1% and 48.2% of patients, respectively (P=.26). Patient characteristics or disease severity were not associated with the attainment of HiSCR or the minimal clinically important differences for the Dermatology Life Quality Index and pain. Cohort study. Respectively, 23.9% and 19.4% of patients had to be excluded from the HiSCR analysis for the tetracycline and combination therapy group because of a low abscess and nodule count at baseline. This study shows significant efficacy of both tetracycline treatment and clindamycin and rifampicin combination therapy after 12weeks in patients with hidradenitis suppurativa. No significant differences in efficacy were observed between the 2 treatments, regardless of disease severity.

Open wounds and rifampicin therapy are associated with rifampicin resistance among staphylococcal vascular graft/endograft infections.

BackgroundOptimal timing for rifampicin combination therapy in patients with staphylococcal vascular graft/endograft infection (S-VGEI) is unknown. Experts recommend adding rifampicin after lowering bacterial load by surgery and wound closure.ObjectivesTo assess predictors of rifampicin resistance among staphylococci isolated from patients in the Vascular Graft Infection Cohort Study.MethodsWe included prospective patients with S-VGEI diagnosis from 1 January 2002 to 30 June 2020. We retrospectively assessed determinants of rifampicin resistance using exact logistic regression and described survival with Kaplan–Meier curves.ResultsWe analysed 513 Staphylococcus spp. among 143 predominantly male (82%) patients with a median age of 68 years (IQR 60–75). Thereof, 82 (57%) received a rifampicin combination therapy and 61 (43%) received an antimicrobial therapy without rifampicin. Among 82 patients with rifampicin, 26/26 patients with any rifampicin resistance had open wounds with a strong association of rifampicin resistance with rifampicin treatment while having open wounds (OR 37, 95% CI 6.1 to ∞). Among 75 patients with a rifampicin combination therapy and rifampicin-susceptible staphylococci at S-VGEI diagnosis, 12/12 patients with a secondary rifampicin-resistant isolate had an open wound (OR 14, 95% CI 2.1 to ∞).ConclusionsRifampicin should be started after wound closure due to increased risk of rifampicin resistance observed while having open wounds or second-look surgeries among patients with S-VGEI.