Effect of Nicorandil, Diltiazem, or Isosorbide Mononitrate for Oral Antispastic Therapy After Coronary Artery Bypass Grafting Using Radial Artery Grafts-A Pilot Randomized Controlled Trial (ASRAB-Pilot): Rationale and Study Protocol

INTRODUCTION

The current evidence for chronic oral antispastic medication use after coronary artery bypass grafting using radial artery grafts (RA-CABG) is controversial. Calcium channel blockers, such as diltiazem, are the most commonly used antispastic medications after RA-CABG; other options include nitrates and nicorandil, but to date no sufficiently powered randomized controlled trials have been conducted to compare their efficacy.

METHODS

This is a single-center, open-label, parallel three-arm, pilot randomized controlled trial. Patients without contraindications to any study medications and who successfully underwent RA-CABG surgery will be consecutively screened. Eligible patients will be randomized in a ratio of 1:1:1 (a total of 150 patients, 50 per arm) to receive nicorandil 5 mg orally thrice daily, diltiazem 180 mg orally once daily, or isosorbide mononitrate 50 mg orally once daily for 24 weeks. The primary outcomes are RA graft failure at week 1 and week 24. The secondary outcomes include major adverse cardiovascular event (MACE, a composite of all-cause death, myocardial infarction, stroke, and unplanned revascularization) and angina recurrence. The safety outcomes include hypotension occurrence, withdrawal of renin angiotensin aldosterone system inhibitors, serious adverse events, and other concerned adverse events within 24 weeks.

CONCLUSION

This pilot trial will compare the preliminary effects of nicorandil, diltiazem, and isosorbide mononitrate on angiographic and clinical outcomes in patients who have undergone RA-CABG. Recruitment began in June 2020, and the estimated primary completion date is early 2023. Results of this study will provide much needed information for design of large confirmatory trials on the effectiveness of oral antispastic medications after RA-CABG.

Isosorbide Mononitrate Versus Dinoprostone for Cervical Ripening During Labor Induction: a Systematic Review and Meta-analysis of Randomized Controlled Trials

The objective of this study was to conduct a systematic review and meta-analysis of all randomized controlled trials (RCTs) that evaluated isosorbide mononitrate (ISMN) versus dinoprostone, a prostaglandin E2 (PGE2) analogue, in promoting cervical ripening during labor induction. We searched five major databases from inception till 02 May 2021. We assessed the risk of bias of included studies. We meta-analyzed various endpoints (n=12) and pooled the endpoints as mean difference (MD) or risk ratio (RR) with 95% confidence interval (CI). Overall, 4 RCTs met the inclusion criteria, comprising 818 patients; equally 409 patients were allocated to ISMN and PGE2 groups. Overall, the RCTs had a low risk of bias. The mean change in Bishop score at 24 h was significantly lower in disfavor of the ISMN group. The mean time from drug administration to delivery was significantly longer in disfavor of the ISMN group. The rate of oxytocin need was significantly higher in disfavor of the ISMN group. The rate of vaginal delivery at 24 h was significantly lower in disfavor of the ISMN group. The rates of headache and palpitations were significantly higher in disfavor of the ISMN group. The rate of abnormal fetal heart rate was significantly lower in favor of the ISMN group. There was no significant difference between both groups with regard to rates of cesarean delivery, postpartum hemorrhage, uterine hyperstimulation, and NICU admission. Compared with PGE2, ISMN appeared less effective for cervical ripening prior to labor induction and correlated with higher drug-related maternal toxicities.

Misoprostol plus isosorbide mononitrate versus misoprostol alone for cervical ripening during labor induction: A systematic review and meta-analysis of randomized controlled trials

AIM

To conduct a systematic review and meta-analysis of all randomized controlled trials (RCTs) that examined the maternal and neonatal outcomes of misoprostol+isosorbide mononitrate (ISMN) versus misoprostol alone (control) in promoting cervical ripening during labor induction.

METHODS

We searched five databases from inception until 05-May-2021. We assessed risk of bias of RCTs, meta-analyzed 23 endpoints, and pooled them as mean difference or risk ratio with 95% confidence interval.

RESULTS

Overall, five RCTs met the inclusion criteria, comprising 850 patients (426 and 424 patients were allocated to misoprostol+ISMN and misoprostol group, respectively). Overall, the RCTs had a low risk of bias. Pertaining to maternal delivery-related outcomes, there was no significant difference between both groups regarding the mean interval from drug administration to delivery, rate of vaginal delivery, rate of cesarean section delivery, and rate of need for oxytocin augmentation. Pertaining to maternal drug-related side effects, the rate of maternal headache was significantly higher in disfavor of the misoprostol+ISMN compared with misoprostol alone. However, the rates of maternal nausea, hypotension, flushing, palpitation, dizziness, postpartum hemorrhage, and uterine tachysystole did not differ between both groups. Pertaining to neonatal outcomes, there was no significant difference between both groups regarding rates of NICU admission, meconium-stained amniotic fluid, and Apgar score <7 at five minutes.

CONCLUSION

Compared with misoprostol alone, co-administration of misoprostol+ISMN did not correlate with superior maternal delivery-related outcomes. The rate of maternal headache was significantly higher in disfavor of the misoprostol+ISMN group. There was no significant difference between both groups regarding neonatal endpoints.

[A study on the targeted nanoparticles of isosorbide mononitrate on reducing the levels of inflammatory factors in rabbit models of rhinosinusitis]

Objective: To investigate the effect of isosorbide mononitrate (ISMN) targeted nanoparticles on inflammatory factors of sinusitis by establishing a rabbit model of rhinosinusitis. Methods: Thirty healthy rabbits, male and female, weighing 2.5-3.5 kg, were randomly divided into 6 groups with 5 rabbits in each group. Group A was the control group. The model of rabbit sinusitis was established in group B to F, and CT was used to confirm the model was successful. After placing tubes into the maxillary sinus in the group C to F, saline, 45 mg/ml ISMN, 45 mg/ml ISMN nanoparticles and 45 mg/ml ISMN targeted nanoparticles were used to wash the maxillary sinus, respectively. Blood samples were collected from the ear vein of rabbits on day 7, 14, 21, 28, 35 and 42 after modeling respectively. Changes in the expression levels of inflammatory factors in rabbits during the modeling process and after drug washing were detected by ELISA. After the drug intervention, the maxillary sinus mucosa was taken for real-time quantitative PCR to detect the changes in the mRNA level of inflammatory factors. SPSS 22.0 software was used to process the data. Results: Rabbit model of sinusitis was successfully established. ELISA showed that after the action of ISMN targeted nanoparticles of 1 week (42th day after modeling), the levels of (interleukin, IL) 4, IL-8, IL-17A and interferon γ (IFN-γ) in the blood were lower compared with that of 35th day after modeling, the difference was statistically significant (5.57±1.20 vs 19.73±0.68, 66.41±11.87 vs 154.68±13.13, 17.96±1.87 vs 28.23±0.80, 53.56±5.66 vs 111.93±7.29, all P<0.05). Compared with the ISMN nanoparticles and ISMN, the ISMN targeted nanoparticles reduced the levels of IL-4, IL-8, IL-17A and IFN-γ more obviously, the differences were statistically significant (13.26±1.43 vs 8.81±1.33 vs 7.14±2.16, 89.47±17.80 vs 41.07±7.77 vs 15.84±3.72, 10.28±2.07 vs 3.06±1.62 vs 1.82±0.90, 62.16±6.18 vs 35.12±4.62 vs 27.89±10.18, all P<0.05). Real-Time PCR showed that after the flushing of ISMN targeted nanoparticles, the levels of IL-4, IL-8, IL-17A and IFN-γ mRNA were lowest compared with that of the model group, ISMN nanoparticles and ISMN group. Conclusion: ISMN targeted nanoparticles can reduce the level of inflammatory factors in rabbit sinusitis model.

Nitric Oxide in the Prevention of Pre-eclampsia (NOPE): A Double-Blind Randomized Placebo-Controlled Trial Assessing the Efficacy of Isosorbide Mononitrate in the Prevention of Pre-eclampsia in High-Risk Women

INTRODUCTION

Pre-eclampsia contributes to maternal and fetal morbidity and mortality all over the world. Endothelial dysfunction is postulated to be the crux of the pathogenesis. Recent meta-analysis of aspirin trials showed aspirin to be effective when started early in pregnancy (at ≤ 16-week gestation). We aimed to study the effect of low-dose prophylactic isosorbide mononitrate (ISMN) 20 mg/day on the incidence of hypertensive diseases in high-risk women receiving standard aspirin prophylaxis.

METHODS

Design: Randomized double-blind placebo-controlled parallel-arm superiority trial. Setting: Antenatal clinic of a tertiary teaching hospital, South India. Participants and methods: One hundred women fulfilling NICE guideline criteria for aspirin prophylaxis recruited at 12-16 weeks were randomized to receive either 20 mg/day of ISMN or placebo, in addition to 75 mg/day of oral aspirin from recruitment till delivery. Main outcome measure: Rate of hypertensive disorder of pregnancy (HDP). Sample Size: One hundred women (50 in each arm) to detect a decrease of HDP from 20% in the placebo group to 5% in the ISMN group with a power of 80% and at 0.05.

RESULTS

One hundred women (50 in each arm) participated and completed the trial. Intention to treat analysis of these 100 women showed that the groups were comparable in terms of age, BMI, parity, and vascular indices (such as mean arterial pressure, uterine artery pulsatility index, flow-mediated vasodilatation index, brachial-ankle pulse wave velocity, Ankle-Brachial Index, brachial arterial stiffness index, and ankle arterial stiffness index). The rate of hypertensive disorders (gestational hypertension, pre-eclampsia, or superimposed pre-eclampsia) was not significantly different between the groups (14/50, 28% in ISMN vs. 12/50, 24% in placebo group; p = 0.7). The mean gestational age at diagnosis of hypertensive disease (35.4 vs. 36 weeks, ISMN vs. placebo groups, p = 0.7) or the rate of severe disease (8/50, 16% in ISMN vs. 7/50, 14% in the placebo group; p = 0.9) did not differ significantly between the two groups. Stillbirths (1 vs. 2), NICU admission rates (18 vs. 10%), and neonatal mortality (2 vs. 2) were also similar between the groups.

CONCLUSION

The results of the randomized controlled trial of nitric oxide in the prevention of pre-eclampsia (NOPE) showed that in high-risk women receiving standard aspirin prophylaxis from less than 16 weeks, there is no significant reduction in the incidence of hypertensive disorders of pregnancy in the ISMN group, to the desired extent. There was no significant effect on the severity of disease, gestational age at diagnosis of disease or maternal-perinatal morbidity due to low-dose isosorbide mononitrate.

Tolerability, safety and intermediary pharmacological effects of cilostazol and isosorbide mononitrate, alone and combined, in patients with lacunar ischaemic stroke: The LACunar Intervention-1 (LACI-1) trial, a randomised clinical trial

BACKGROUND

Lacunar stroke, a frequent clinical manifestation of small vessel disease (SVD), differs pathologically from other ischaemic stroke subtypes and has no specific long-term secondary prevention. Licenced drugs, isosorbide mononitrate (ISMN) and cilostazol, have relevant actions to prevent SVD progression.

METHODS

We recruited independent patients with clinically confirmed lacunar ischaemic stroke without cognitive impairment to a prospective randomised clinical trial, LACunar Intervention-1 (LACI-1). We randomised patients using a central web-based system, 1:1:1:1 with minimisation, to masked ISMN 25 mg bd, cilostazol 100 mg bd, both ISMN and cilostazol started immediately, or both with start delayed. We escalated doses to target over two weeks, sustained for eight weeks. Primary outcome was the proportion achieving target dose. Secondary outcomes included symptoms, safety (haemorrhage, recurrent vascular events), cognition, haematology, vascular function, and neuroimaging. LACI-1 was powered (80%, alpha 0.05) to detect 35% (90% versus 55%) difference between the proportion reaching target dose on one versus both drugs at 55 patients. Registration ISRCTN12580546.

FINDINGS

LACI-1 enrolled 57 participants between March 2016 and August 2017: 18 (32%) females, mean age 66 (SD 11, range 40-85) years, onset-randomisation 203 (range 6-920) days. Most achieved full (64%) or over half (87%) dose, with no difference between cilostazol vs ISMN, single vs dual drugs. Headache and palpitations increased initially then declined similarly with dual versus single drugs. There was no between-group difference in BP, pulse-wave velocity, haemoglobin or platelet function, but pulse rate was higher (mean difference, MD, 6.4, 95%CI 1.2-11.7, p = 0.02), platelet count higher (MD 35.7, 95%CI 2.8, 68.7, p = 0.03) and white matter hyperintensities reduced more (Chi-square p = 0.007) with cilostazol versus no cilostazol.

INTERPRETATION

Cilostazol and ISMN are well tolerated when the dose is escalated, without safety concerns, in patients with lacunar stroke. Larger trials with longer term follow-up are justified.

FUNDING

Alzheimer's Society (AS-PG-14-033).

Mechanistic studies of the antibiofilm activity and synergy with antibiotics of isosorbide mononitrate

The use of nitric oxide (NO), a naturally occurring antimicrobial agent, as an alternative strategy to combat bacterial biofilms has recently gained considerable momentum in light of the global threat of emerging antibiotic resistance. While previous NO-based anti-biofilm approaches were aimed at killing bacterial cells within biofilms, NO has also been recently identified as a key mediator of biofilm dispersal, causing the release of cells from the biofilm community. This is of great interest towards the design of more effective anti-biofilm strategies but further studies are warranted to validate this concept. Therefore, in the present study we investigated whether a NO precursor, isosorbide mononitrate (ISMN) or its analogue D-isosorbide can induce bacteria cell dispersal from Staphylococcus aureus (S. aureus) biofilms and explored the potential synergy of ISMN and the antimicrobial compounds mupirocin and ciprofloxacin in biofilm eradication. This study demonstrate that ISMN causes dispersal of S. aureus biofilm bacteria, particularly when exposed to high levels of drug. ISMN at 60mg/mL increased the number of colony forming units (CFU) (~3log₁₀ and ~5log₁₀) of planktonic bacteria after 6 and 24-h exposure respectively, compared to control biofilms. This suggests that ISMN induces the transition of sessile biofilm cells to free-swimming planktonic cells. In addition, ISMN exhibits synergistic effects against S. aureus biofilms with ciprofloxacin when tested above its minimum inhibitory concentration (MIC). Specifically, exposure to ISMN significantly enhanced the efficacy of ciprofloxacin by reducing the number of CFU (~3log₁₀ or ~2log₁₀) of biofilm-associated and planktonic bacteria respectively, compared to drug alone. Combined exposure to both ISMN and certain antimicrobial agents may therefore offer an innovative approach to control persistent biofilm and biofilm-associated infections.

Fixed-Dose Versus Off-Label Combination of Isosorbide Dinitrate Plus Hydralazine Hydrochloride: Retrospective Propensity-Matched Analysis in Black Medicare Patients with Heart Failure

INTRODUCTION

Based upon the findings of the African-American Heart Failure Trial, the US Food and Drug Administration approved the fixed-dose combination of isosorbide dinitrate (ISDN) and hydralazine hydrochloride (HYD) (FDC-ISDN/HYD) as a new drug for treatment of heart failure (HF) in self-identified African Americans. According to the FDA, FDC-ISDN/HYD has no therapeutic equivalent. However, off-label combinations of the separate generic drugs ISDN and HYD (OLC-ISDN+HYD) or isosorbide mononitrate (ISMN) and HYD (OLC-ISMN+HYD) are routinely substituted without any supporting outcome data. We conducted an exploratory retrospective propensity-matched cohort study using Medicare data to determine whether a survival difference exists between these treatments in medication-adherent patients.

METHODS

Black Medicare beneficiaries with HF were matched with Medicare Part D data to identify patients with prescriptions to FDC-ISDN/HYD or the off-label combinations. Only patients with 1-year adherence levels ≥80% were included in the analysis. Propensity-matched scoring created two sets of matched cohort pairs on a 1:1 basis, each set comparing FDC-ISDN/HYD with one of the off-label combinations. Kaplan-Meier (KM) survival curves with the log-rank test were then calculated for each pair for the year of medication adherence.

RESULTS

The analysis population was relatively older (77 years) and mainly female (66.7%), with a high burden of comorbid disease. The KM estimates of 1-year survival were 87.9% (95% CI 85.6-89.9%) and 83.0% (95% CI 80.3-85.3%) (log rank p = 0.0024), respectively, for the matched cohorts FDC-ISDN/HYD and OLC-ISDN+HYD (n = 886 in each group) and 88.2% (95% CI 85.9-90.2%) and 84.8% (95% CI 82.2-87.0%) (log rank p = 0.0320), respectively, for the matched cohorts FDC-ISDN/HYD and OLC-ISMN+HYD (n = 868 in each group).

CONCLUSION

The 1-year survival advantage for FDC-ISDN/HYD compared with off-label combinations in adherent black Medicare beneficiaries with HF suggests a genuine difference between these medications and warrants prospective investigation.

Evaluation of Isosorbide Mononitrate for Preinduction of Cervical Ripening: A Randomized Placebo-Controlled Trial

OBJECTIVE

To evaluate the safety and efficacy of Isosorbide mononitrate (IMN) as a cervical ripening agent prior to induction of labour in term pregnant women.

MATERIALS AND METHODS

A randomized placebo-controlled study was conducted on 100 term singleton pregnancies planned for induction of labour. The participants were randomly assigned to two groups. One group received 40 mg IMN and the other group received 40mg of placebo kept vaginally. The main outcome of this study was to evaluate the efficacy of IMN in cervical ripening based on the change in modified Bishop score and the effect on time duration between the drug insertion and delivery. Safety of isosorbide mononitrate was assessed by measuring variables related to maternal and neonatal outcomes.

RESULTS

Baseline demographic characteristics were similar in both groups. The mean change in modified Bishop score after 2 doses of 40mg IMN was insignificant when compared to placebo. Though IMN shortened the time duration between the drug insertion to delivery when compared to placebo, it was statistically insignificant. The need for oxytocin and 2(nd) ripening agent was less in IMN group when compared to placebo group but statistically this also proved to be insignificant. It was noted that there was an increase in caesarean deliveries in IMN than in placebo group. IMN did not cause any significant change in maternal hemodynamics and adverse side effects. Though NICU admission and stay was less in IMN than in placebo group, it was statistically insignificant.

CONCLUSION

Though IMN did not cause any maternal and neonatal adverse effects, it was found to be inefficient in comparison to placebo as a cervical ripening agent.

Isosorbide Mononitrate a Nitric Oxide Donor: A Study of Its Efficacy and Safety as an Agent for Cervical Ripening

OBJECTIVE

To study the efficacy and safety profile of isosorbide mononitrate (IMN) as an agent for cervical ripening.

METHODOLOGY

This study was conducted in the Department of Obstetrics and Gynecology, M Y Hospital & M G M Medical College Indore from September 2011 to February 2013. Pregnant women attending the antenatal clinics were screened for possible participation in the study after explaining the nature of the study. This study was conducted on 150 patients. An initial dose of 40 mg IMN was applied in the posterior vaginal fornix, and the same dose was repeated after 6 h. Cervical ripening was assessed by the change in Bishop Score 12 h after the initial application.

RESULTS

In a study of 150 cases, mean maternal age was 22.2 ± 2.6 years (range 19-35 years) and mean gestational age was 40.5 ± 1.07 (range 40-42 weeks). 52 women were primigravidas, while 98 were multigravidas. The mean Bishop Score-before drug administration was 1.94 ± 1.3 (range 0-5), and mean fetal heart rate was 137 ± 6.2 bpm. The mean of Bishop scores before IMN administration was 1.94 ± 1.3, while mean of Bishop score after drug administration was 6.7 ± 2.2; mean difference was equal to 4.76. P value was equal to 0.0001. By conventional criteria, this difference is considered to be statistically significant. The mode of delivery 96 (64 %) delivered vaginally, while 54 (36 %) were delivered by Cesarean section. Mean Apgar score at 1 min was 8.2 ± 0.9 SD (range 7-10), while mean Apgar score at 5 min was 9.4 ± 0.6 (range 8-10). The only side effect noted was headache, and 30 cases (20 %) complained of headache.

CONCLUSION

IMN seems to be effective, safe, inexpensive, and well-tolerated agent for cervical ripening. It is cost effective and safe with minimal side effects.