Prevention of Renal Complications Induced by Non- Steroidal Anti-Inflammatory Drugs

The Role of Organic Small Molecules in Pain Management

In this review, a timeline starting at the willow bark and ending in the latest discoveries of analgesic and anti-inflammatory drugs will be discussed. Furthermore, the chemical features of the different small organic molecules that have been used in pain management will be studied. Then, the mechanism of different types of pain will be assessed, including neuropathic pain, inflammatory pain, and the relationship found between oxidative stress and pain. This will include obtaining insights into the cyclooxygenase action mechanism of nonsteroidal anti-inflammatory drugs (NSAID) such as ibuprofen and etoricoxib and the structural difference between the two cyclooxygenase isoforms leading to a selective inhibition, the action mechanism of pregabalin and its use in chronic neuropathic pain, new theories and studies on the analgesic action mechanism of paracetamol and how changes in its structure can lead to better characteristics of this drug, and cannabinoid action mechanism in managing pain through a cannabinoid receptor mechanism. Finally, an overview of the different approaches science is taking to develop more efficient molecules for pain treatment will be presented.

Improved l-Type amino acid transporter 1 (LAT1)-mediated delivery of anti-inflammatory drugs into astrocytes and microglia with reduced prostaglandin production

Non-steroidal anti-inflammatory drugs (NSAIDs) can have protective effects in the brain by inhibition of cyclooxygenases (COX). However, the delivery into the brain across the blood-brain barrier (BBB) and particularly into the brain parenchymal cells is hindered. Therefore, in the present study, we developed four l-type amino acid transporter 1 (LAT1)-utilizing prodrugs of flurbiprofen, ibuprofen, naproxen, and ketoprofen, since LAT1 is expressed on both, the BBB endothelial cells as well as parenchymal cells. The cellular uptake and utilization of LAT1 by novel prodrugs were studied in mouse cortical primary astrocytes and immortalized microglia (BV2), and the release of the parent NSAID in several tissue and cell homogenates. Finally, the effects of the studied prodrugs on prostaglandin E₂ (PGE₂) production and cell viability were explored. The gained results showed that all four prodrugs were carried into their target cells via LAT1. They also released their parent NSAIDs via carboxylesterases (CES) and most likely also other un-identified enzymes, which need to be carefully considered when administrating these compounds orally or intravenously. Most importantly, all the studied prodrugs reduced the PGE₂ production in astrocytes and microglia after lipopolysaccharide (LPS)-induced inflammation by 29-94% and without affecting the cell viability with the studied concentration (20 µM).

Therapeutic Manipulation of Macrophages Using Nanotechnological Approaches for the Treatment of Osteoarthritis

Osteoarthritis (OA) is the most common joint pathology causing severe pain and disability. Macrophages play a central role in the pathogenesis of OA. In the joint microenvironment, macrophages with an M1-like pro-inflammatory phenotype induce chronic inflammation and joint destruction, and they have been correlated with the development and progression of the disease, while the M2-like anti-inflammatory macrophages support the recovery of the disease, promoting tissue repair and the resolution of inflammation. Nowadays, the treatment of OA in the clinic relies on systemic and/or intra-articular administration of anti-inflammatory and pain relief drugs, as well as surgical interventions for the severe cases (i.e., meniscectomy). The disadvantages of the pharmacological therapy are related to the chronic nature of the disease, requiring prolonged treatments, and to the particular location of the pathology in joint tissues, which are separated anatomical compartments with difficult access for the drugs. To overcome these challenges, nanotechnological approaches have been investigated to improve the delivery of drugs toward macrophages into the diseased joint. This strategy may offer advantages by reducing off-target toxicities and improving long-term therapeutic efficacy. In this review, we describe the nanomaterial-based approaches designed so far to directly or indirectly manipulate macrophages for the treatment of osteoarthritis.

Practice Advisory on the Appropriate Use of NSAIDs in Primary Care

Cyclo-oxygenase (COX)-2 selective and nonselective nonsteroidal anti-inflammatory drugs (NSAIDs) are important in managing acute and chronic pain secondary to inflammation. As a greater understanding of the risks of gastrointestinal (GI), cardiovascular (CV) and renal events with NSAIDs use has emerged, guidelines have evolved to reflect differences in risks among NSAIDs. Updated guidelines have yet to reflect new evidence from recent trials which showed similar CV event rates with celecoxib compared to naproxen and ibuprofen, and significantly better GI tolerability for celecoxib. This practice advisory paper aims to present consensus statements and associated guidance regarding appropriate NSAID use based on a review of current evidence by a multidisciplinary group of expert clinicians. This paper is especially intended to guide primary care practitioners within Asia in the appropriate use of NSAIDs in primary care. Following a literature review, group members used a modified Delphi consensus process to determine agreement with selected recommendations. Agreement with a statement by 75% of total voting members was defined a priori as consensus. For low GI risk patients, any nonselective NSAID plus proton pump inhibitor (PPI) or celecoxib alone is acceptable treatment when CV risk is low; for high CV risk patients, low-dose celecoxib or naproxen plus PPI is appropriate. For high GI risk patients, celecoxib plus PPI is acceptable for low CV risk patients; low-dose celecoxib plus PPI is appropriate for high CV risk patients, with the alternative to avoid NSAIDs and consider opioids instead. Appropriate NSAID prescription assumes that the patient has normal renal function at commencement, with ongoing monitoring recommended. In conclusion, appropriate NSAID use requires consideration of all risks.

Protective effect of cilastatin against diclofenac-induced nephrotoxicity through interaction with diclofenac acyl glucuronide via organic anion transporters

BACKGROUND AND PURPOSE

Diclofenac is a widely used nonsteroidal anti-inflammatory drug. However, adverse effects in the kidney limit its clinical application. The present study was aimed to evaluate the potential effect of cilastatin on diclofenac-induced acute kidney injury and to clarify the potential roles of renal organic anion transporters (OATs) in the drug-drug interaction between cilastatin and diclofenac.

EXPERIMENTAL APPROACH

The effect of cilastatin was evaluated in diclofenac-induced acute kidney injury in mice. Human OAT1/3-transfected HEK293 cells and renal primary proximal tubule cells (RPTCs) were used to investigate OAT1/3-mediated transport and the cytotoxicity of diclofenac.

KEY RESULTS

Cilastatin treatment decreased the pathological changes, renal dysfunction and elevated renal levels of oxidation products, cytokine production and apoptosis induced by diclofenac in mice. Moreover, cilastatin increased the plasma concentration and decreased the renal distribution of diclofenac and its glucuronide metabolite, diclofenac acyl glucuronide (DLF-AG). Similarly, cilastatin inhibited cytotoxicity and mitochondrial damage in RPTCs but did not change the intracellular accumulation of diclofenac. DLF-AG but not diclofenac exhibited OAT-dependent cytotoxicity and was identified as an OAT1/3 substrate. Cilastatin inhibited the intracellular accumulation and decreased the cytotoxicity of DLF-AG in RPTCs.

CONCLUSION AND IMPLICATIONS

Cilastatin alleviated diclofenac-induced acute kidney injury in mice by restoring the redox balance, suppressing inflammation, and reducing apoptosis. Cilastatin inhibited OATs and decreased the renal distribution of diclofenac and DLF-AG, which further ameliorated the diclofenac-induced nephrotoxicity in mice. Cilastatin can be potentially used in the clinic as a therapeutic agent to alleviate the adverse renal reaction to diclofenac.

Radiofrequency endometrial ablation for treating heavy menstrual bleeding in women with chronic renal failure

OBJECTIVE

The study objective was to retrospectively evaluate the efficacy and safety of radiofrequency endometrial ablation in treating heavy menstrual bleeding (HMB) in women with chronic renal failure (CRF).

METHOD

Fifty-eight patients with CRF undergoing radiofrequency endometrial ablation in our hospital between January 2013 and July 2017 and for whom complete follow-up data were available were included. Outcome measures included amenorrhea, treatment failure and operative complications.

RESULTS

The mean patient age was 41.4 ± 7.7 years, the mean preoperative hemoglobin level was 69.6 ± 19.3 g/dL, the mean preoperative serum creatinine level was 879.1 ± 415.4 µmol/L, and the mean urea level was 18.2 ± 7.1 mmol/L. The mean treatment time for radiofrequency endometrial ablation was 61.7 ± 18.8 s. The median volume of estimated blood loss during the procedure was 10 mL (a range of 2-50 mL). On average, the study subjects were monitored for 24.4 months (a range of 6-60 months). The average amenorrhea rate was 89.7%. Only 2 (3.4%) patients required additional gynecologic surgery after endometrial ablation. Intra- and postoperative complications were not observed.

CONCLUSION

Radiofrequency endometrial ablation was demonstrated to be safe and effective for the treatment of HMB in women with CRF.

Cannabinoids and Pain: New Insights From Old Molecules

Cannabis has been used for medicinal purposes for thousands of years. The prohibition of cannabis in the middle of the 20th century has arrested cannabis research. In recent years there is a growing debate about the use of cannabis for medical purposes. The term ‘medical cannabis’ refers to physician-recommended use of the cannabis plant and its components, called cannabinoids, to treat disease or improve symptoms. Chronic pain is the most commonly cited reason for using medical cannabis. Cannabinoids act via cannabinoid receptors, but they also affect the activities of many other receptors, ion channels and enzymes. Preclinical studies in animals using both pharmacological and genetic approaches have increased our understanding of the mechanisms of cannabinoid-induced analgesia and provided therapeutical strategies for treating pain in humans. The mechanisms of the analgesic effect of cannabinoids include inhibition of the release of neurotransmitters and neuropeptides from presynaptic nerve endings, modulation of postsynaptic neuron excitability, activation of descending inhibitory pain pathways, and reduction of neural inflammation. Recent meta-analyses of clinical trials that have examined the use of medical cannabis in chronic pain present a moderate amount of evidence that cannabis/cannabinoids exhibit analgesic activity, especially in neuropathic pain. The main limitations of these studies are short treatment duration, small numbers of patients, heterogeneous patient populations, examination of different cannabinoids, different doses, the use of different efficacy endpoints, as well as modest observable effects. Adverse effects in the short-term medical use of cannabis are generally mild to moderate, well tolerated and transient. However, there are scant data regarding the long-term safety of medical cannabis use. Larger well-designed studies of longer duration are mandatory to determine the long-term efficacy and long-term safety of cannabis/cannabinoids and to provide definitive answers to physicians and patients regarding the risk and benefits of its use in the treatment of pain. In conclusion, the evidence from current research supports the use of medical cannabis in the treatment of chronic pain in adults. Careful follow-up and monitoring of patients using cannabis/cannabinoids are mandatory.

Biomonitoring the cardiorenal effects of Luehea divaricata Mart.: An ethnoguided approach

ETHNOPHARMACOLOGICAL RELEVANCE

Luehea divaricata Mart. (Malvaceae) is an important medicinal species that is widely used as a diuretic in the Brazilian Pantanal region. An ethanolic supernatant that was obtained from an infusion of leaves of this species (ESLD) was recently shown to exert hypotensive and diuretic activity. Nevertheless, the secondary metabolites that are responsible for this activity and the molecular mechanisms of pharmacological action remain unknown.

AIM

We performed a detailed study to identify possible active metabolites that are present in different ESLD fractions and investigated their effects on renal and peripheral arteriolar tone. We further evaluated their interrelations with sustained diuretic and hypotensive actions.

MATERIALS AND METHODS

The ESLD was first obtained from L. divaricata leaves, and liquid-liquid fractionation was performed. The fractions were analyzed by liquid chromatography-mass spectrometry. An ethyl acetate fraction (AceFr), n-butanolic fraction (ButFr), and aqueous fraction (AqueFr) were then orally administered in male Wistar rats in a single dose or daily for 7 days. The doses were previously defined based on the yield that was obtained from each fraction. Hydrochlorothiazide was used as a positive control. Blood pressure, heart rate, urinary volume, pH, density, and urinary sodium, potassium, chloride, and calcium levels were measured. Serum levels of nitrite, thiobarbituric acid reactive species, nitrotyrosine, aldosterone, vasopressin, and plasma angiotensin converting enzyme activity were also measured. Finally, the direct effects of the ButFr on renal and mesenteric arteriolar tone and the role of nitric oxide and prostaglandins in the renal and hemodynamic effects were investigated.

RESULTS

Of the fractions that were tested, only the ButFr exerted significant diuretic and saluretic effects. The AceFr and ButFr also had acute hypotensive effects, but only the ButFr maintained its response after 7 days of treatment. Prolonged treatment with the ButFr increased serum nitrite levels and significantly reduced oxidative and nitrosative markers of stress. Additionally, the ButFr caused a vasodilatory response in the renal and mesenteric arteriolar beds through the release of nitric oxide and prostaglandins. Finally, the diuretic and hypotensive effects of the ButFr were completely blocked by pretreatment with Nω-nitro-L-arginine methyl ester and indomethacin, thus demonstrating the direct involvement of nitric oxide and prostaglandins in these effects.

CONCLUSION

The ButFr that was obtained from Luehea divaricata exerted sustained diuretic and hypotensive effects. These effects were apparently attributable to the release of nitric oxide and prostaglandins, which reduce renal and peripheral arteriolar tone and lead to an increase in the glomerular filtration rate and a reduction of global peripheral resistance. These findings suggest that the ButFr may be a potential complementary therapy for several conditions in which diuretic and hypotensive effects are required.

Antenatal exposure to nonsteroidal anti-inflammatory drugs and risk of neonatal hypertension

Nonsteroidal anti-inflammatory drugs (NSAIDs) are used as tocolytics, which are medications that suppress uterine contractions for preterm birth prevention. Their effect on cerebral/systemic vascular beds poses the question of whether antenatal NSAID exposure is associated with neonatal hypertension. We performed a retrospective case-control study in a tertiary neonatal intensive care unit, including 40 hypertension cases (hospitalized neonates ≥ 35 weeks with systolic BP > 100 mm Hg on three consecutive days) compared to 134 controls matched by gestational age at delivery, plurality, and delivery date. Cases and controls were compared by antenatal NSAID exposure, other common tocolytics, and maternal/neonatal characteristics and complications. Multivariable logistic regression was used to estimate the odds of hypertension among those with prenatal exposure to NSAIDs versus those without exposure. Newborns with hypertension had a lower gestational age at delivery and increased incidence of neonatal complications, including respiratory distress syndrome, bronchopulmonary dysplasia, surfactant administration, longer duration of ventilation, and history of umbilical artery catheterization. Days of indomethacin exposure were positively associated with greater odds of neonatal hypertension (OR 1.17 [1.00 to 1.38], P = 0.055), even after adjustment for other factors associated with neonatal hypertension. Newborns with hypertension were less likely to have been exposed to calcium channel blockers as a tocolytic. The results of our study suggest an association between prenatal exposure to nonsteroidal anti-inflammatory drugs and neonatal hypertension. Furthermore, our data suggest that prenatal calcium channel blocker exposure may protect against the development of neonatal hypertension. Future multicenter studies are needed to understand the risks of tocolytics and subsequent consequences in preterm infants.

The Competitive Senior Athlete

Clinicians should discuss common health issues of the older population and how medical problems affect their sports performance. Patients with chronic conditions, such as hypertension and diabetes mellitus, benefit from participation in sports. However, special care should be taken to keep the patient healthy and minimize effects of these conditions and their treatments in athletic performance. Another important consideration in the older athlete is fluid ingestion and the increased risk of dehydration. There is evidence that physical exercise reduces pain in osteoarthritis and enhances physical function of affected joints. Older athletes often use multiple medications and dietary supplements; Clinicians should educate patients about possible effects of medications in sports performance.

Therapeutic potential of mesenchymal stem cell based therapy for osteoarthritis

Osteoarthritis (OA) is a chronic degenerative disease affecting articular cartilage in joints, and it is a leading cause of disability in the United States. Current pharmacological treatment strategies are ineffective to prevent the OA progression; however, cellular therapies have the potential to regenerate the lost cartilage, combat cartilage degeneration, provide pain relief, and improve patient mobility. One of the most promising sources of cellular regenerative medicine is from mesenchymal stem cells (MSCs). MSCs can be isolated from adipose tissue, bone marrow, synovial tissue, and other sources. The aim of this review is to compile recent advancement in cellular based therapy more specifically in relation to MSCs in the treatment of osteoarthritis.

Assessing the negative impact of phenyl alkanoic acid derivative, a frequently prescribed drug for the suppression of pain and inflammation, on the differentiation and proliferation of chondrocytes

Background

Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently prescribed to relieve pain and inflammation. These NSAIDs have also analgesic effects and can be administered via oral, injectable, and topical routes. During inflammation, a number of synovial mediators and cytokines are released which decrease the pH level of the synovial fluid. Administration of acidic NSAIDs further decreases the pH levels and hence contributes to the destruction of the cartilage. To our knowledge, no cellular-based study regarding the chondrotoxicity of phenyl alkanoic acid derivatives on NSAIDs was conducted before. Thus, the aim of this pioneering study was to examine the effect of frequently prescribed NSAIDs, a phenyl alkanoic acid derivative, flurbiprofen, on the proliferation and differentiation of human primer chondrocyte cultures in vitro.

Methods

Primer chondrocyte cultures were prepared from osteochondral tissue obtained during surgery for gonarthrosis. Samples not exposed to the pharmacological agent were used as the control group. The samples were treated with 1, 10, 100, 250, 500, or 1000 μM of the agent for 24, 48, and 72 h. The cell viability, toxicity, and proliferation were assessed with MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) analysis and prechondrocytic precursor stage-specific embryonic antigen-1 (SSEA-1) expression using a commercial ELISA kit spectrophotometrically. The surface morphology of the samples in each group was compared using an inverted light microscope and an environmental scanning electron microscope (ESEM). An analysis of variance was used to compare between-group differences. Tukey’s honest significant difference (HSD) method (95 % confidence interval) was used to evaluate the differences and significance in averages. The alpha significance value was considered <0.01.

Results

Statistically significant cytotoxicity was observed in the treatment groups. NSAID had a significant negative effect on the proliferation and differentiation of chondrocytes as compared to the control group (p < 0.01).

Conclusion

Before administering phenyl alkanoic acid derivatives in the clinical setting, their role in suppressing the proliferation and differentiation of chondrocytes should be taken into account. Thus, caution should be given when prescribing these drugs.