Molecular Basis for Ligand Modulation of a Mammalian Voltage-Gated Ca2+ Channel.

The L-type voltage-gated Ca2+ (Cav) channels are modulated by various compounds exemplified by 1,4-dihydropyridines (DHP), benzothiazepines (BTZ), and phenylalkylamines (PAA), many of which have been used for characterizing channel properties and for treatment of hypertension and other disorders. Here, we report the cryoelectron microscopy (cryo-EM) structures of Cav1.1 in complex with archetypal antagonistic drugs, nifedipine, diltiazem, and verapamil, at resolutions of 2.9 Å, 3.0 Å, and 2.7 Å, respectively, and with a DHP agonist Bay K 8644 at 2.8 Å. Diltiazem and verapamil traverse the central cavity of the pore domain, directly blocking ion permeation. Although nifedipine and Bay K 8644 occupy the same fenestration site at the interface of repeats III and IV, the coordination details support previous functional observations that Bay K 8644 is less favored in the inactivated state. These structures elucidate the modes of action of different Cav ligands and establish a framework for structure-guided drug discovery.

Risk of postpartum readmission after hypertensive disorder of pregnancy and variation by discharge antihypertensive medication prescription.

BACKGROUND: Patients with hypertensive disorders of pregnancy have a high rate of postpartum readmission. OBJECTIVE: This study aimed to evaluate whether the type of antihypertensive medication prescribed at discharge was associated with postpartum readmission after a hypertensive disorder of pregnancy. STUDY DESIGN: This was a retrospective cohort study of 57,254 pregnancies complicated by hypertensive disorders of pregnancy between 2012 and 2018 in the electronic obstetrical database of Kaiser Permanente Northern California. Postpartum readmissions occurred within 6 weeks after discharge from delivery hospitalization. Cox regression models were used to evaluate the association between the type of antihypertensive medication prescription at discharge (none, labetalol only, nifedipine only, or 2 or more antihypertensive medications) and postpartum readmission, adjusted for type of hypertensive disorder of pregnancy, final inpatient systolic and diastolic blood pressures, age, body mass index, mode of delivery, insurance status, race and ethnicity, delivery facility, comorbidity score, smoking, preterm delivery, parity, and Neighborhood Deprivation Index. RESULTS: Among eligible patients with a hypertensive disorder of pregnancy, 1696 (3.0%) were readmitted within 6 weeks. Approximately 86% of patients were discharged without a prescription for antihypertensive medication; among those discharged with a prescription for antihypertensive medication, most were prescribed either labetalol only (54%) or nifedipine only (30%). The unadjusted readmission risk was the highest for patients discharged with a prescription for labetalol only (7.6%), lower for those discharged with a prescription for nifedipine only (3.6%) or 2 or more antihypertensive medications (3.2%), and the lowest for those discharged without a prescription for antihypertensive medication (2.5%). In the adjusted models, compared with discharge without a prescription for antihypertensive medication, discharge with a prescription for labetalol only was associated with a 63% (hazard ratio, 1.63; 95% confidence interval, 1.41-1.88) greater incidence of postpartum readmission, and discharge with a prescription for nifedipine only and discharge with a prescription for 2 or more antihypertensive medications were associated with 26% (hazard ratio, 0.74; 95% confidence interval, 0.59-0.93) and 47% (hazard ratio, 0.53; 95% confidence interval, 0.38-0.74) lower incidence of postpartum readmission, respectively. There was no strong evidence to suggest that the effect of the type of antihypertensive medication at discharge on the incidence of readmission varied by race and ethnicity (interaction P=.88). The results indicating an elevated risk associated with labetalol use were consistent in models that excluded patients with prepregnancy hypertension. CONCLUSION: Discharge with a prescription for nifedipine alone or multiple antihypertensive medications (vs no medication) was associated with a lower incidence of readmission, whereas discharge with a prescription for labetalol alone was associated with an elevated readmission incidence. A large-scale, prospective research to compare the effectiveness of commonly prescribed hypertension medications at discharge is warranted.

PBPK/PD Modeling of Nifedipine for Precision Medicine in Pregnant Women: Enhancing Clinical Decision-Making for Optimal Drug Therapy.

OBJECTIVE: This study aims to develop physiologically based pharmacokinetic and pharmacodynamic (PBPK/PD) predictive models for nifedipine in pregnant women, enhancing precision medicine and reducing adverse reactions for both mothers and infants. METHODS: A PBPK/PD model was constructed using PK-Sim, MoBi, and MATLAB software, integrating literature and pregnancy-specific physiological information. The process involved: (1) establishing and validating a PBPK model for serum clearance after intravenous administration in non-pregnant individuals, (2) establishing and validating a PBPK model for serum clearance after oral administration in non-pregnant individuals, (3) constructing and validating a PBPK model for enzyme clearance after oral administration in non-pregnant individuals, and (4) adjusting the PBPK model structure and enzyme parameters according to pregnant women and validating it in oral administration. (5) PK/PD model was explored through MATLAB, and the PBPK and PK/PD models were integrated to form the PBPK/PD model. RESULTS: The Nifedipine PBPK model's predictive accuracy was confirmed by non-pregnant and pregnant validation studies. The developed PBPK/PD model accurately predicted maximum antihypertensive effects for clinical doses of 5, 10, and 20 mg. The model suggested peak effect at 0.86 h post-administration, achieving blood pressure reductions of 5.4 mmHg, 14.3 mmHg, and 21.3 mmHg, respectively. This model provides guidance for tailored dosing in pregnancy-induced hypertension based on targeted blood pressure reduction. CONCLUSION: Based on available literature data, the PBPK/PD model of Nifedipine in pregnancy demonstrated good predictive performance. It will help optimize individualized dosing of Nifedipine, improve treatment outcomes, and minimize the risk of adverse reactions in mothers and infants.

Comparison of the efficacy of nifedipine with ritodrine, nitroglycerine and magnesium sulfate for the management of preterm labor: a systematic review and meta-analysis.

BACKGROUND: Some studies have compared the efficacy of nifedipine with that of other tocolytic drugs in the treatment of preterm labor, but the reported results are conflicting. OBJECTIVE: To compare the efficacy of nifedipine with that of ritodrine, nitroglycerine and magnesium sulfate for the management of preterm labor. METHODS: In this systematic review and meta-analysis, PubMed/MEDLINE, Scopus, Clarivate Analytics Web of Science, and Google Scholar were searched until April 3,2024 using predefined keywords. Randomized controlled trials (RCTs) and clinical trials that compared the efficacy of nifedipine with that of ritodrine, nitroglycerine and magnesium sulfate for the management of preterm labor were included. Two authors independently reviewed the articles, assessed their quality and extracted the data. The quality of the included RCTs based on the Cochrane Risk of Bias Tool 1 for clinical trial studies. The risk difference (RD) with the associated 95% confidence interval (CI) was calculated. A forest plot diagram was used to show the comparative point estimates of nifedipine and other tocolytic drugs on the prevention of preterm labor and their associated 95% confidence intervals based on the duration of pregnancy prolongation. Study heterogeneity was evaluated by the I2 index, and publication bias was evaluated by Egger's test. RESULTS: Forty studies enrolling 4336 women were included. According to our meta-analysis, there was a significant difference in the prolongation of preterm labor within the first 48 h between the nifedipine group and the nitroglycerine group (RD, -0.04; 95% CI, -0.08 to -0.00; I2: 32.3%). Additionally, there were significant differences between nifedipine and ritodrine (RD, 0.11; 95% CI, 0.02 to 0.21; I2, 51.2%) for more than one week RD, 0.10; 95% CI, 0.03 to 0.19; I2, 33.2%) and for 34 weeks and more. The difference between nifedipine and magnesium sulfate was not significant in any of the four time points. CONCLUSIONS: Considering the superiority of nifedipine over ritodrine and nitroglycerine and its similar efficacy to magnesium sulfate for tocolysis, it seems that the side effects of these options determine the first drug line.

Efficient administration of a combination of nifedipine and sildenafil citrate versus only nifedipine on clinical outcomes in women with threatened preterm labor: a systematic review and meta-analysis.

BACKGROUND: Preterm labor (PTL) is a common and serious pregnancy disorder that can cause long-term neurological issues in the infant. There are conflicting studies concerning whether sildenafil citrate (SC) reduces preterm labor complications. Therefore, the meta-analysis aimed to examine the clinical outcomes in women with threatened PTL who received nifedipine plus SC therapy versus only nifedipine. METHODS: For the original articles, six databases were searched using relevant keywords without restriction on time or language until January 13, 2024. The Cochrane risk-of-bias tool for randomized trials (RoB) and the Risk of Bias Assessment Tool for Nonrandomized Studies (RoBANS) were both used to assess the risk of bias in randomized and non-randomized studies, and GRADE determined the quality of our evidence. Meta-analysis of all data was carried out using Review Manager (RevMan) version 5.1. RESULTS: Seven studies with mixed quality were included in the meta-analysis. The study found that combining nifedipine and SC resulted in more prolongation of pregnancy (MD = 6.99, 95% CI: 5.32, 8.65, p < 0.00001), a lower rate of delivery in the 1st to 3rd days after hospitalization (RR = 0.62, 95% CI: 0.50, 0.76, p < 0.00001), a higher birth weight (252.48 g vs. nifedipine alone, p = 0.02), and the risk ratio of admission to the neonatal intensive care unit (NICU) was significantly lower (RR = 0.62, 95% CI: 0.50, 0.76, p < 0.00001) compared to nifidepine alone. The evidence was high for prolongation of pregnancy, delivery rate 24-72 h after admission, and NICU admission, but low for newborn birth weight. CONCLUSIONS: Given the effectiveness of SC plus nifedipine in increased prolongation of pregnancy and birth weight, lower delivery in the 1st to 3rd days after hospitalization, and NICU admission, Gynecologists and obstetricians are suggested to consider this strategy for PTL management, although additional article rigor is required to improve the quality of the evidence.

Effect of nifedipine administration before embryo transfer on reproductive outcome in ICSI cycles, a double-blind control trial study.

PURPOSE: Nifedipine is a calcium channel blocker with smooth muscle relaxing properties. This study set out to investigate the efficacy of nifedipine administered orally before embryo transfer (ET) on the improvement of the intracytoplasmic sperm injection (ICSI) outcome. This randomized, double-blind, comparator-controlled, was carried out between 2019 and 2020 in the infertility center of Babol, Iran. 200 women candidates for ICSI and recipients of frozen-thawed ET aged 18-40 years were randomly assigned in the ratio 1:1 to an intervention group that received nifedipine 20 mg tablets orally 30 min before ET (n = 100) or to a group of placebo (n = 100). A randomization center in Babol University of Medical Science used computer-generated numbers to allocate treatments. The allocation treatment was blind to the participants, the sonographer of endometer monitoring, the staff of the ICSI laboratory, and the outcome assessor. The primary analysis was based on the intention-to-treat principle done on 200 participants, (n = 100), comparing chemical pregnancy rates in the two comparing groups at 14 days' follow-up after ET. Implantation rate and clinical pregnancy were considered secondary outcomes. RESULT: 200 participants were analyzed. There is no significant difference in the number of oocytes and the quality of embryos in the nifedipine and placebo groups. Despite a numerical increase in the rate of chemical pregnancy, there were no statistical differences in the study group versus the comparison group (24% vs 14%, P = 0.1, rate ratio 0.88, 95% CI 0.77 to 1.01), respectively. Also, no significant increase in clinical pregnancy was found compared with the placebo (17% vs 8%, P = 0.26, rate ratio 0.90, 0.81 to 1.00). CONCLUSION: Nifedipine administered orally 30 min before embryo transfer did not improve the chemical pregnancy rate, and clinical pregnancy rate in infertile women undergoing ICSI. This trial has been registered on the Iranian Clinical Trials Registration Site (IRCT) with the number IRCT20180417039338N3.

A new three-dimensional (3D) molecularly imprinted polymer fluoroprobe based on green-red dual-emission signals of carbon quantum dots and self-polymerization of dopamine (CDs@PDA-MIPs) for sensitive detection of nifedipine.

Nifedipine (NIF), as one of the dihydropyridine calcium channel blockers, is widely used in the treatment of hypertension. However, misuse or ingestion of NIF can result in serious health issues such as myocardial infarction, arrhythmia, stroke, and even death. It is essential to design a reliable and sensitive detection method to monitor NIF. In this work, an innovative molecularly imprinted polymer dual-emission fluorescent sensor (CDs@PDA-MIPs) strategy was successfully designed for sensitive detection of NIF. The fluorescent intensity of the probe decreased with increasing NIF concentration, showing a satisfactory linear relationship within the range 1.0 × 10-6 M ~ 5.0 × 10-3 M. The LOD of NIF was 9.38 × 10-7 M (S/N = 3) in fluorescence detection. The application of the CDs@PDA-MIPs in actual samples such as urine and Qiangli Dingxuan tablets has been verified, with recovery ranging from 97.8 to 102.8% for NIF. Therefore, the fluorescent probe demonstrates great potential as a sensing system for detecting NIF.

Wilderness Medical Society Clinical Practice Guidelines for the Prevention, Diagnosis, and Treatment of Acute Altitude Illness: 2024 Update.

To provide guidance to clinicians about best practices, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for prevention, diagnosis, and treatment of acute mountain sickness, high altitude cerebral edema, and high altitude pulmonary edema. Recommendations are graded based on the quality of supporting evidence and the balance between the benefits and risks/burdens according to criteria put forth by the American College of Chest Physicians. The guidelines also provide suggested approaches for managing each form of acute altitude illness that incorporate these recommendations as well as recommendations on how to approach high altitude travel following COVID-19 infection. This is an updated version of the original WMS Consensus Guidelines for the Prevention and Treatment of Acute Altitude Illness published in Wilderness & Environmental Medicine in 2010 and the subsequently updated WMS Practice Guidelines for the Prevention and Treatment of Acute Altitude Illness published in 2014 and 2019.

Cocrystal Prediction of Nifedipine Based on the Graph Neural Network and Molecular Electrostatic Potential Surface.

Nifedipine (NIF) is a dihydropyridine calcium channel blocker primarily used to treat conditions such as hypertension and angina. However, its low solubility and low bioavailability limit its effectiveness in clinical practice. Here, we developed a cocrystal prediction model based on Graph Neural Networks (CocrystalGNN) for the screening of cocrystals with NIF. And scoring 50 coformers using CocrystalGNN. To validate the reliability of the model, we used another prediction method, Molecular Electrostatic Potential Surface (MEPS), to verify the prediction results. Subsequently, we performed a second validation using experiments. The results indicate that our model achieved high performance. Ultimately, cocrystals of NIF were successfully obtained and all cocrystals exhibited better solubility and dissolution characteristics compared to the parent drug. This study lays a solid foundation for combining virtual prediction with experimental screening to discover novel water-insoluble drug cocrystals.

Blockade of L-Type Ca2+ Channel Activity Alleviates Oligodendrocyte Pathology following Brain Injury in Male Rats.

A growing body of studies suggests that Ca2+ signaling controls a variety of biological processes in brain elements. Activation of L-type voltage-operated Ca2+ channels (VOCCs) plays a role in the development of oligodendrocyte (OL) lineage loss, and indicates that the blocking of these channels may be an effective way to inhibit OL lineage cell loss. For this study, 10.5-day-old male Sprague-Dawley rats were used to generate cerebellar tissue slices. The slice tissues were cultured and randomly allocated to one of four groups (six each) and treated as follows: Group I, (sham control); Group II, 0.1% dimethyl sulfoxide (DMSO) only (vehicle control); Group III, injury (INJ); Group IV, (INJ and treatment with NIF). The injury was simulated by exposing the slice tissues to 20 min of oxygen-glucose deprivation (OGD). At 3 days post-treatment, the survival, apoptosis, and proliferation of the OL lineages were measured and compared. Results: In the INJ group, there was a decrease in mature myelin basic protein+ OLs (MBP+ OLs) and their precursors, NG2+ OPCs (Nerve-glia antigen 2+ oligodendrocyte precursor cell), compared with controls. A significant elevation was observed in the NG2+ OPCs and apoptotic MBP+ OLs as confirmed by a TUNEL assay. However, the cell proliferation rate was decreased in NG2+ OPCs. NIF increased OL survival as measured by apoptosis rate in both OL lineages and preserved the rate of proliferation in the NG2+ OPCs. Conclusions: Activation of L-type VOCCs may contribute to OL pathology in association with reduced mitosis of OPCs following brain injury as a strategy to treat demyelinating diseases.

Spotted fever rickettsia-induced microvascular endothelial barrier dysfunction is delayed by the calcium channel blocker benidipine.

The tick-borne bacterium Rickettsia parkeri is an obligate intracellular pathogen that belongs to spotted fever group rickettsia (SFGR). The SFG pathogens are characterized by their ability to infect and rapidly proliferate inside host vascular endothelial cells that eventually result in impairment of vascular endothelium barrier functions. Benidipine, a wide range dihydropyridine calcium channel blocker, is used to prevent and treat cardiovascular diseases. In this study, we tested whether benidipine has protective effects against rickettsia-induced microvascular endothelial cell barrier dysfunction in vitro. We utilized an in vitro vascular model consisting of transformed human brain microvascular endothelial cells (tHBMECs) and continuously monitored transendothelial electric resistance (TEER) across the cell monolayer. We found that during the late stages of infection when we observed TEER decrease and when there was a gradual increase of the cytoplasmic [Ca2+], benidipine prevented these rickettsia-induced effects. In contrast, nifedipine, another cardiovascular dihydropyridine channel blocker specific for L-type Ca2+ channels, did not prevent R. parkeri-induced drop of TEER. Additionally, neither drug was bactericidal. These data suggest that growth of R. parkeri inside endothelial cells is associated with impairment of endothelial cell monolayer integrity due to Ca2+ flooding through specific, benidipine-sensitive T- or N/Q-type Ca2+ channels but not through nifedipine-sensitive L-type Ca2+ channels. Further study will be required to discern the exact nature of the Ca2+ channels and Ca2+ transporting system(s) involved, any contributions of the pathogen toward this process, as well as the suitability of benidipine and new dihydropyridine derivatives as complimentary therapeutic drugs against Rickettsia-induced vascular failure.

Association between clinical use of nifedipine and the risk of osteoporosis: a nationwide retrospective cohort study.

Nifedipine is one of the common calcium channel blockers (CCBs) for hypertension that induce peroxisome-proliferator-activated receptor γ coactivator 1-α, which is envisioned as a potential therapeutic target in bone disease. The findings of this retrospective cohort study suggest that patients who receive nifedipine may have a potential protective effect on osteoporosis in comparison to other CCBs. INTRODUCTION: Nifedipine was one L-type dihydropyridine calcium channel blocker (CCB) that can improve bone loss. However, epidemiological studies on the association between the use of nifedipine and osteoporosis risk are limited. Thus, this study aimed to evaluate the association between the clinical use of nifedipine and the risk of osteoporosis. METHODS: This retrospective cohort was conducted using the National Health Insurance Research Database of Taiwan from 2000 to 2013. The study includes 1225 patients receiving nifedipine (the exposed cohort) and 4900 patients receiving other CCBs (the comparison cohort). The primary outcome was the diagnosis of osteoporosis. The hazard ratios (HRs) and 95% confidence intervals (CIs) were used to assess the association between the use of nifedipine and the risk of osteoporosis. RESULTS: Patients receiving nifedipine treatment had a reduced risk of osteoporosis as compared with those undergoing other CCB treatments (adjusted HR, 0.44; 95% CI, 0.37-0.53). Moreover, this inverse association is evident in both sexes and various age groups. CONCLUSIONS: This population-based cohort study demonstrated that nifedipine may have potential protective effect on osteoporosis compared with other CCBs. The clinical implications of the present study need further investigation.

Implications of Drug-Polymer Interactions on Time-Temperature-Transformation: A Tool to Assess the Crystallization Propensity in Amorphous Solid Dispersions.

The critical cooling rate (CRcrit) to prevent drug crystallization during the preparation of nifedipine amorphous solid dispersions (ASDs) was determined through the time-temperature-transformation (TTT) diagram. ASDs were prepared with polyvinylpyrrolidone, hydroxypropylmethyl cellulose acetate succinate, and poly(acrylic acid). ASDs were subjected to isothermal crystallization over a wide temperature range, and the time and temperature dependence of nifedipine crystallization onset time (tC) was determined by differential scanning calorimetry (DSC) and synchrotron X-ray diffractometry. TTT diagrams were generated for ASDs, which provided the CRcrit for the dispersions prepared with each polymer. The observed differences in CRcrit could be explained in terms of differences in the strength of interactions. Stronger drug-polymer interactions led to longer tC and decreased CRcrit. The effect of polymer concentrations (4-20% w/w) was also influenced by the strength of the interaction. The CRcrit of amorphous NIF was ∼17.5 °C/min. Addition of 20% w/w polymer resulted in a CRcrit of ∼0.05, 0.2, and 11 °C/min for the dispersions prepared with PVP, HPMCAS, and PAA, respectively.

Understanding the Effect of Nucleation in Amorphous Solid Dispersions through Time-Temperature Transformation.

In an earlier investigation, the critical cooling rate to prevent drug crystallization (CRcrit) during the preparation of nifedipine (NIF) amorphous solid dispersions (ASDs) was determined through a time-temperature transformation (TTT) diagram (Lalge et al. Mol. Pharmaceutics 2023, 20 (3), 1806-1817). The current study aims to use the TTT diagram to determine the critical cooling rate to prevent drug nucleation (CRcrit N) during the preparation of ASDs. ASDs were prepared with each polyvinylpyrrolidone (PVP) and hydroxypropyl methylcellulose acetate succinate (HPMCAS). The dispersions were first stored under conditions promoting nucleation and then heated to the temperature that favors crystallization. The crystallization onset time (tC) was determined by differential scanning calorimetry and synchrotron X-ray diffractometry. TTT diagrams for nucleation were generated, which provided the critical nucleation temperature (50 °C) and the critical cooling rate to avoid nucleation (CRcrit N). The strength of the drug-polymer interactions as well as the polymer concentration affected the CRcrit N, with PVP having a stronger interaction than HPMCAS. The CRcrit of amorphous NIF was ∼17.5 °C/min. The addition of a 20% w/w polymer resulted in CRcrit of ∼0.05 and 0.2 °C/min and CRcrit N of ∼4.1 and 8.1 °C/min for the dispersions prepared with PVP and HPMCAS, respectively.

Arrest of mouse preterm labor until term delivery by combination therapy with atosiban and mundulone, a natural product with tocolytic efficacy.

There is a lack of FDA-approved tocolytics for the management of preterm labor (PL). In prior drug discovery efforts, we identified mundulone and mundulone acetate (MA) as inhibitors of in vitro intracellular Ca2+-regulated myometrial contractility. In this study, we probed the tocolytic potential of these compounds using human myometrial samples and a mouse model of preterm birth. In a phenotypic assay, mundulone displayed greater efficacy, while MA showed greater potency and uterine-selectivity in the inhibition of intracellular-Ca2+ mobilization. Cell viability assays revealed that MA was significantly less cytotoxic. Organ bath and vessel myography studies showed that only mundulone exerted inhibition of myometrial contractions and that neither compounds affected vasoreactivity of ductus arteriosus. A high-throughput combination screen identified that mundulone exhibits synergism with two clinical-tocolytics (atosiban and nifedipine), and MA displayed synergistic efficacy with nifedipine. Of these combinations, mundulone+atosiban demonstrated a significant improvement in the in vitro therapeutic index compared to mundulone alone. The ex vivo and in vivo synergism of mundulone+atosiban was substantiated, yielding greater tocolytic efficacy and potency on myometrial tissue and reduced preterm birth rates in a mouse model of PL compared to each single agent. Treatment with mundulone after mifepristone administration dose-dependently delayed the timing of delivery. Importantly, mundulone+atosiban permitted long-term management of PL, allowing 71% dams to deliver viable pups at term (>day 19, 4-5 days post-mifepristone exposure) without visible maternal and fetal consequences. Collectively, these studies provide a strong foundation for the development of mundulone as a single or combination tocolytic for management of PL.

Low-dose nifedipine rescues impaired endothelial progenitor cell-mediated angiogenesis in diabetic mice.

It is of great clinical significance to develop potential novel strategies to prevent diabetic cardiovascular complications. Endothelial progenitor cell (EPC) dysfunction is a key contributor to diabetic vascular complications. In the present study we evaluated whether low-dose nifedipine could rescue impaired EPC-mediated angiogenesis and prevent cardiovascular complications in diabetic mice. Diabetes was induced in mice by five consecutive injections of streptozotocin (STZ, 60 mg·kg-1·d-1, i.p.). Diabetic mice were treated with low-dose nifedipine (1.5 mg·kg-1·d-1, i.g.) for six weeks. Then, circulating EPCs in the peripheral blood were quantified, and bone marrow-derived EPCs (BM-EPCs) were prepared. We showed that administration of low-dose nifedipine significantly increased circulating EPCs, improved BM-EPCs function, promoted angiogenesis, and reduced the cerebral ischemic injury in diabetic mice. Furthermore, we found that low-dose nifedipine significantly increased endothelial nitric oxide synthase (eNOS) expression and intracellular NO levels, and decreased the levels of intracellular O2.- and thrombospondin-1/2 (TSP-1/2, a potent angiogenesis inhibitor) in BM-EPCs of diabetic mice. In cultured BM-EPCs, co-treatment with nifedipine (0.1, 1 µM) dose-dependently protected against high-glucose-induced impairment of migration, and suppressed high-glucose-induced TSP-1 secretion and superoxide overproduction. In mice with middle cerebral artery occlusion, intravenous injection of diabetic BM-EPCs treated with nifedipine displayed a greater ability to promote local angiogenesis and reduce cerebral ischemic injury compared to injection of diabetic BM-EPCs treated with vehicle, and the donor-derived BM-EPCs homed to the recipient ischemic brain. In conclusion, low-dose nifedipine can enhance EPCs' angiogenic potential and protect against cerebral ischemic injury in diabetic mice. It is implied that chronic treatment with low-dose nifedipine may be a safe and economic manner to prevent ischemic diseases (including stroke) in diabetes.

Efficacy of Oral Nifedipine, Naproxen, or Placebo for Pain Relief During Diagnostic Hysteroscopy in an Office Setting: A Randomized Pilot Study.

STUDY OBJECTIVE: To compare nifedipine, naproxen, or placebo for pain relief during diagnostic hysteroscopy. DESIGN: Double-blind, randomized controlled pilot study. SETTING: University hospital. PATIENTS: Women scheduled for office diagnostic hysteroscopy (n = 60). INTERVENTIONS: Women received nifedipine (2 tablets of 10 mg), naproxen (2 tablets of 250 mg), or placebo (2 tablets of 500 mg lactose) 30 to 60 minutes prior to hysteroscopy. MEASUREMENTS AND MAIN RESULTS: Sixty patients were enrolled in the study (21 in the nifedipine group, 19 in the naproxen group, and 20 in the placebo group). The median pain scores during hysteroscope insertion, measured on a Visual Analog Scale (VAS), were 1 (interquartile range (IQR) 0-0), 2 (0-4) and 1 (0-1) in the nifedipine, naproxen and placebo group, respectively (P,14). The median VAS scores during hysteroscopy were 5 (IQR 2-7), 5 (4-8) and 5 (3-7) in the nifedipine, naproxen and placebo group, respectively (P,73). The median VAS scores immediately after hysteroscopy were 2 (IQR 0-4), 3 (0-6) and 3 (1-5) in the nifedipine, naproxen and placebo group, respectively (P,40). The median VAS scores 30 minutes after hysteroscopy were 1 (IQR 0-2), 1 (0-1) and 1 (0-2) in the nifedipine, naproxen and placebo group, respectively (P,63). Hysteroscope insertion failed in 1 case (naproxen group) because of cervica`l stenosis (P,32). Flushes, fatigue and vertigo, 30 minutes after the procedure, were significantly more prevalent in the nifedipine group compared to the naproxen (p < .001, p,03, p,03, respectively) and the placebo group (p < .001, p,01, p,01, respectively). Palpitations occurred only in the nifedipine group (p < .001). The day after the procedure, the headache was most prevalent in the nifedipine group compared to the naproxen group (p,001) and the placebo group (p,001). CONCLUSION: In our pilot study, pain relief and success rates for office diagnostic hysteroscopy were not significantly different between nifedipine, naproxen, and placebo. Nifedipine was associated with more, albeit tolerable, side-effects.

LC-MS/MS bioanalytical method for the quantitative analysis of nifedipine, bisoprolol, and captopril in human plasma: Application to pharmacokinetic studies.

In this study, the development and validation of an accurate and highly sensitive LC-MS/MS method were performed for the estimation of nifedipine, bisoprolol and captopril in real human plasma. Liquid-liquid extraction using tert-butyl methyl ether was efficiently applied for extraction of the analytes from plasma samples. The chromatographic separation was carried out using an isocratic elution mode on the X-terra MS C18 column (4.6 × 50 mm, 3.5 µm). The mobile phase consisted of methanol-0.1% formic acid (95:5, v/v) for determination of nifedipine and bisoprolol and acetonitrile-0.1% formic acid (70:30, v/v) for determination of captopril with a flow rate of 0.5 ml/min. Acceptable results regarding the different validation characteristics of the analytes were obtained in accordance with US Food and Drug Administration recommendations for bioanalytical methods. The developed approach was linear over concentration ranges of 0.5-130.0, 50.0-4,500.0 and 0.3-30.0 ng/ml for nifedipine, captopril and bisoprolol, respectively. The method revealed a sufficient lower limit of quantification in the range of 0.3-50.0 ng/ml, as well as high recovery percentages, indicating high bioanalytical applicability. The proposed method was efficiently applied to a pharmacokinetic evaluation of a fixed-dose combination of the analytes in healthy male volunteers.

Does preoperative administration of hypotensive agents affect the quality of the surgical field during endoscopic sinus surgery? A triple-blind randomized controlled trial.

PURPOSE: Endoscopic sinus surgery (ESS) is a surgical procedure widely used in the treatment of various sinonasal conditions. Excessive bleeding during ESS leads to potentially major complications. The primary aim of this trial was to explore any different effects of bisoprolol and nifedipine on the intraoperative surgical field. In addition, the correlations regarding surgical field state, total blood loss (TBL), mean arterial pressure (MAP), and heart rate (HR) were also examined. METHODS: A prospective, triple-blinded, randomized, placebo-controlled trial was conducted, including 72 patients between 18 and 65 years of age who underwent ESS. As an indicator of the worst state of the intraoperative surgical field, the Boezaart scale score was used, as evaluated by two surgeons. Appropriate statistical analysis was conducted to explore score comparisons across groups and correlations between vital signs, bleeding, and the operative field state. RESULTS: No statistically significant difference was found among different intervention groups regarding the worst state of the surgical field (p = 0.367 > 0.05). The Boezaart scale score was positively correlated with TBL (rxy = 0.619, p = 0.000 < 0.001) and MAP (rxy = 0.259, p = 0.028 < 0.05). Furthermore, MAP was positively correlated with HR (rs = 0.254, p = 0.32 < 0.05). CONCLUSION: Our study demonstrates that preoperative administration of bisoprolol and nifedipine does not affect the worst state of the operative field. However, vital signs seem to either directly or indirectly affect bleeding and operative field state, and agents affecting them are worth exploring further.

Acute Cardiovascular and Cardiorespiratory Effects of JWH-018 in Awake and Freely Moving Mice: Mechanism of Action and Possible Antidotal Interventions?

JWH-018 is the most known compound among synthetic cannabinoids (SCs) used for their psychoactive effects. SCs-based products are responsible for several intoxications in humans. Cardiac toxicity is among the main side effects observed in emergency departments: SCs intake induces harmful effects such as hypertension, tachycardia, chest pain, arrhythmias, myocardial infarction, breathing impairment, and dyspnea. This study aims to investigate how cardio-respiratory and vascular JWH-018 (6 mg/kg) responses can be modulated by antidotes already in clinical use. The tested antidotes are amiodarone (5 mg/kg), atropine (5 mg/kg), nifedipine (1 mg/kg), and propranolol (2 mg/kg). The detection of heart rate, breath rate, arterial oxygen saturation (SpO2), and pulse distention are provided by a non-invasive apparatus (Mouse Ox Plus) in awake and freely moving CD-1 male mice. Tachyarrhythmia events are also evaluated. Results show that while all tested antidotes reduce tachycardia and tachyarrhythmic events and improve breathing functions, only atropine completely reverts the heart rate and pulse distension. These data may suggest that cardiorespiratory mechanisms of JWH-018-induced tachyarrhythmia involve sympathetic, cholinergic, and ion channel modulation. Current findings also provide valuable impetus to identify potential antidotal intervention to support physicians in the treatment of intoxicated patients in emergency clinical settings.