Anxiety, a significant risk factor for coronary artery disease: what is the best index.

BACKGROUND: Coronary artery disease (CAD) is known as the leading cause of disability and death globally. Anxiety disorders are also recognized as common types of mental disorders that substantially impact global health. Iran ranks among the countries with a high incidence of CAD and anxiety disorders. Therefore, the present study aims to determine the potential association and epidemiological aspects of anxiety and CAD within the population of Mashhad, the second most popoulos city in Iran. METHODS: The present study is based on extracted data from the Mashhad stroke and heart atherosclerotic disorder (MASHAD) study which is a 10-year prospective cohort study intended to assess the effects of various CAD risk factors among Mashhad city residents. Anxiety scores were assessed at the baseline using Beck Anxiety Inventory and individuals were classified based on the BAI 4-factor structure model which included autonomic, cognitive, panic, and neuromotor components. Accordingly, the association between baseline anxiety scores and the BAI four-factor model with the risk of CAD events was analyzed using SPSS software version 21. RESULTS: Based on the results, 60.4% of the sample were female, and 5.6% were classified as having severe forms of anxiety. Moreover, severe anxiety was more prevalent in females. Results showed a 1.7% risk of CAD (p-value < 0.001) over 10 years with one unit increase in anxiety score. Based on the 4-factor model structure, we found that only panic disorder could significantly increase the risk of CAD by 1.1% over the 10-year follow-up (p-value < 0.001). CONCLUSION: Anxiety symptoms, particularly panic disorder, are independently and significantly associated with an increased overall risk of developing CAD over a 10-year period. Therefore, further studies are warranted to investigate the mechanisms through which anxiety may cause CAD, as well as possible interventions to mitigate these processes.

Evaluating the Protective Effects of Thymoquinone on Methamphetamine-induced Toxicity in an In Vitro Model Based on Differentiated PC12 Cells.

Methamphetamine (Meth) is a highly addictive stimulant. Its potential neurotoxic effects are mediated through various mechanisms, including oxidative stress and the initiation of the apoptotic process. Thymoquinone (TQ), obtained from Nigella sativa seed oil, has extensive antioxidant and anti-apoptotic properties. This study aimed to investigate the potential protective effects of TQ against Meth-induced toxicity by using an in vitro model based on nerve growth factor-differentiated PC12 cells. Cell differentiation was assessed by detecting the presence of a neuronal marker with flow cytometry. The effects of Meth exposure were evaluated in the in vitro neuronal cell-based model via the determination of cell viability (in an MTT assay) and apoptosis (by annexin/propidium iodide staining). The generation of reactive oxygen species (ROS), as well as the levels of glutathione (GSH) and dopamine, were also determined. The model was used to determine the protective effects of 0.5, 1 and 2 µM TQ against Meth-induced toxicity (at 1 mM). The results showed that TQ reduced Meth-induced neurotoxicity, possibly through the inhibition of ROS generation and apoptosis, and by helping to maintain GSH and dopamine levels. Thus, the impact of TQ treatment on Meth-induced neurotoxicity could warrant further investigation.

An overview on nanoplatforms for statins delivery: Perspectives for safe and effective therapy.

Statins are the most widely used pharmacological agents for reducing blood cholesterol levels and treating atherosclerotic cardiovascular diseases. Most of the statins' derivatives have been limited by water solubility, bioavailability, and oral absorption, which has led to adverse effects on several organs, especially at high doses. As an approach to reducing statin intolerance, achieving a stable formulation with improved efficacy and bioavailability at low doses has been suggested. Nanotechnology-based formulations may provide a therapeutic benefit over traditional formulations in terms of potency and biosafety. Nanocarriers can provide tailored delivery platforms for statins, thereby enhancing the localized biological effects and lowering the risk of undesired side effects while boosting statin's therapeutic index. Furthermore, tailored nanoparticles can deliver the active cargo to the desired site, which culminates in reducing off-targeting and toxicity. Nanomedicine could also provide opportunities for therapeutic methods by personalized medicine. This review delves into the existing data on the potential improvement of statin therapy using nano-formulations.

Mucocutaneous alterations and complications in amphetamine abusers: a narrative review.

Amphetamines are the second most commonly used illicit drug worldwide. Amphetamine use can result in significant cutaneous morbidity. This review highlights the dermatological manifestations of amphetamine abuse.

Crosslinked hydrogel loaded with chitosan-supported iron oxide and silver nanoparticles as burn wound dressing.

Burns can result in infection, disability, psychosocial and economic issues. Advanced wound dressings like hydrogel absorb exudate and maintain moisture. Considering the antimicrobial properties of silver nanoparticles and iron oxide nanoparticles, the efficiency of cross-linked hydrogel loaded with chitosan-supported iron oxide and silver nanoparticles for burn wounds repair was investigated in animal model. Cellulose hydrogel dressing made from carboxymethylcellulose and hydroxyethylcellulose crosslinked with different concentrations of citric acid (10, 15, 20, and 30%) was produced. The physicochemical characteristics of the synthetized hydrogels including Fourier-Transform Infrared spectroscopy, Thermal behavior, Swelling properties, and Scanning Electron Microscope (SEM) were evaluated. The silver nanoparticles and iron nanoparticles were produced and the characteristics, cytotoxicity, antimicrobial activities and their synergistic effect were investigated. After adding nanoparticles to hydrogels, the effects of the prepared wound dressings were investigated in a 14-day animal model of burn wound. The results showed that the mixture comprising 12.5 ppm AgNps, and IONPs at a concentration ≤100 ppm was non-cytotoxic. Moreover, the formulations with 20% CA had a swelling ratio of almost 250, 340, and 500 g/g at pHs of 5, 6.2, and 7.4 after one hour, which are lower than those of formulations with 5 and 10% CA. The total mass loss (59.31%) and the exothermic degradation happened in the range of 273-335 °C and its Tm was observed at 318.52 °C for hydrogels with 20% CA. Thus, the dressing comprising 20% CA which was loaded with 12.5 ppm silver nanoparticles (AgNPs) and 100 ppm iron oxide nanoparticles (IONPs) indicated better physicochemical, microbial and non-cytotoxic characteristics, and accelerated the process of wound healing after 14 days. It was concluded that the crosslinked hydrogel loaded with 12.5 ppm AgNPs and 100 ppm IONPs possesses great wound healing activity and could be regarded as an effective topical burn wound healing treatment.

Verbascoside inhibits paraquate-induced pulmonary toxicity via modulating oxidative stress, inflammation, apoptosis and DNA damage in A549 cell.

Paraquat (PQ), one of the most frequently used herbicides, can cause serious health problems in an exposed individual. In the present study, we investigated the protective effect of verbascoside (VB), a phenylpropanoid glycoside from lemon verbena, against PQ-induced A549 cell injury with a particular focus on the possible molecular pathways involved. A549 cells were exposed to PQ (300 µM) and different concentrations of VB (12.5, 25, and 50 µM). Cell viability, ROS content, the level of antioxidant enzymes (SOD, CAT and GPx) and inflammatory markers (IL-6 and TNF-α), as well as 8-OHdG, were detected using MTT assay and an ELISA kit. Western blotting and qRT-PCR were performed to measure the levels of caspase3 and NF-κB mRNA and protein expression. Exposure of cells to PQ caused viability loss and ROS increase. PQ also increased the levels of IL-6, TNF-α and 8-OHdG and decreased the antioxidant enzymes content. PQ treatment resulted in cell death by increasing the gene and protein expression level of caspase 3 and NF-κB. Treatment with VB notably increased cell survival, antioxidant enzymes activity, which concomitantly attenuated ROS, NF-κB and inflammatory mediator production. VB also inhibited apoptosis expression markers. These results indicated that VB could protect A549 cells against PQ induced cell injury by attenuation of ROS and inflammatory marker production and modulation of antioxidant enzymes. VB efficiently suppressed increased NF-κB and caspase-3 activity and formation of 8-OHdG and ultimately improved cell viability. Therefore, VB may be useful in the development of a new therapy for PQ-induced pulmonary toxicity.

Effects of Boswellia species on viral infections with particular attention to SARS-CoV-2.

The emergence of pathogenic viruses is a worldwide frequent cause of diseases and, therefore, the design of treatments for viral infections stands as a significant research topic. Despite many efforts, the production of vaccines is faced with many obstacles and the high rate of viral resistance caused a severe reduction in the efficacy of antiviral drugs. However, the attempt of developing novel natural drugs, as well as the exertion of medicinal plants, may be an applicable solution for the treatment of viral diseases. Boswellia species exhibited a wide range of pharmacological activities in various conditions such as bronchial asthma, rheumatism, and Crohn's illness. Additionally, pharmacological studies reported the observance of practical antiviral activities from different parts of this substance, especially the oleo-gum-resin. Therefore, this work provided an overview on the antiviral properties of Boswellia species and their potential therapeutic effects in the field of COVID-19 pandemic.

Protective Effect of Portulaca oleracea on Streptozotocin-Induced Type I Diabetes-Associated Reproductive System Dysfunction and Inflammation.

BACKGROUND: Type-one diabetes (T1D), a chronic autoimmune disease with marked inflammatory responses, is associated with infertility complications and implications. Based on the anti-diabetic, antioxidant, and anti-hyperlipidemic potential of Portulaca oleracea (PO), this study aimed to evaluate the protective effect of this plant extract on streptozotocin-induced type-I-diabetes-associated reproductive system dysfunction and inflammation. METHODS: Male rats were randomly divided into four experimental groups: control, diabetic, and treatment/s (PO extract at 100 or 300 mg/kg/daily). Then food and water consumption, body, testis and epididymis weights, histopathological evaluation, seminiferous tubules diameter, sperm count and motility, glucose levels, sex hormones, and inflammatory and oxidative stress markers were evaluated. RESULTS: Our results showed that streptozotocin-induced diabetes significantly increased food and water consumption; increased glucose, MDA, TGF-ß1, and TNF-α levels; and decreased the seminiferous tubules diameter, sperm count and motility, levels of LH, testosterone, total thiol, VEGF, and SOD activity. Interestingly, PO extract (phytochemically characterized by using liquid chromatography-mass spectrometry to detect bioactive molecules) significantly ameliorated these parameters and histopathological indexes' damage in rats. CONCLUSION: Even if more preclinical assessments are needed to better characterize the mechanism/s of action, the results of this study will pave the way for the rational use of PO on diabetic-associated clinical complications and implications.

Advances in treatment of acute sulfur mustard poisoning - a critical review.

Sulfur mustard (SM) is a blistering chemical warfare agent that was used during the World War I and in the Iraq-Iran conflict. The aim of this paper is to discuss and critically review the published results of experiments on the treatment of SM poisoning based on our clinical and research experience. The victims must remove from the contaminated zone immediately. The best solution for decontamination is large amounts of water, using neutral soap and 0.5% sodium hypochlorite. Severely intoxicated patients should be treated according to advanced life support protocols and intensive care therapy for respiratory disorders and the chemical burn. Sodium thiosulfate infusion (100-500 mg/kg/min) should be started up to 60 min after SM exposure. However, N-acetyle cysteine (NAC) is recommended, none of them acts as specific or effective antidote. The important protective and conservative treatment of SM-induced pulmonary injuries include humidified oxygen, bronchodilators, NAC as muculytic, rehydration, mechanical ventilation, appropriate antibiotics and respiratory physiotherapy as clinically indicated. Treatment of acute SM ocular lesions start with topical antibiotics; preferably sulfacetamide eye drop, continue with lubricants, and artificial tears. Treatment for cutaneous injuries include: moist dressing; preferably with silver sulfadiazine cream, analgesic, anti-pruritic, physically debridement, debridase, Laser debridement, followed by skin autologous split-thickness therapy as clinically indicated. The new suggested medications and therapeutic approaches include: anti-inflammatory agents, Niacinamide, Silibinin, Calmodulin antagonists, Clobetasol, full-thickness skin grafting for skin injuries; Doxycycline; Bevacizumab, and Colchicine for ocular injuries. Recommended compounds based on animal studies include Niacinamide, Aprotinin, des-aspartate-angiotensin-I, Gamma-glutamyltransferase, vitamin E, and vitamin D. In vitro studies revealed that Dimethylthiourea, L-nitroarginine, Methyl-ester, Sodium pyruvate, Butylated hydroxyanisole, ethacrynic acid, and macrolide antibiotics are effective. However, none of them, except macrolide antibiotics have been proved clinically. Avoidance of inappropriate polypharmacy is advisable.

Delayed Complications and Long-Term Management of Sulfur Mustard Poisoning: A Narrative Review of Recent Advances by Iranian Researchers Part ІІ: Clinical Management and Therapy.

The present study aimed to review and discuss the recommended and recently suggested protocols by Iranian researchers for a long-term treatment of delayed complications of sulfur mustard (DCSM) in veterans. As indicated clinically, patients who suffer from delayed ocular complications of sulfur mustard (DOCS) benefit from treatments for dry eyes, therapeutic contact lenses, amniotic membrane transplantation; blepharorrhaphy, tarsorrhaphy, limbal stem cell transplantation; corneal transplantation, topical steroids, and immunosuppressive. In spite of penetrating keratoplasty, lamellar keratoplasty and keratolimbal allograft had a good long-term survival. Delayed respiratory complications (DRCS) are the most common effects and life-threatening in Iranian veterans. The recommended treatment protocols include regular clinical evaluations, respiratory physiotherapy and rehabilitation, N-acetyl cysteine; warm humidified air, long-acting b2-agonists, and inhaled corticosteroids. Azithromycin has also been effective in improving clinical conditions, pulmonary function tests, inflammatory indexes, and life quality of the veterans. Interferon gamma (IFN-γ) and helium: oxygen combination were also used in severe DRCS with good results. Some of the delayed cutaneous complications (DCCS) such as itching affects the quality of life of victims. Regular but not frequent showering and bathing, applying sunscreen compounds, topical corticosteroids, and systemic antihistamines reduce the problems of DCCS patients. Several compounds such as capsaicin cream, pimecrolimus, IFN-γ, phenol-menthol; Aloe vera/olive oil cream, cetirizine, doxepine, and hydroxyzine were evaluated in DCCS patients with some benefits. The physicians in charge of veterans emphasize the importance of a healthy lifestyle, appropriate financial/social/cultural supports, and a degree of reassurance and supportive care on the clinical improvement of patients.

Evaluation of teratogenic effects of crocin and safranal, active ingredients of saffron, in mice.

Saffron (Crocus sativus) is a widely used food additive for its color and taste. Crocin and safranal are two main components of this plant. Numerous studies are underway to introduce saffron and its active ingredients as pharmacological agents. Safety assessments of these compounds are important parts of this endeavor. In this study, the effects of crocin and safranal administrations during embryogenesis have been investigated in mice. A total of 75 BALB/c pregnant mice were divided into six experimental and control groups. Four experimental groups received intraperitoneal injection of crocin (200 mg/kg or 600 mg/kg) daily or safranal (0.075 ml/kg or 0.225 ml/kg) on gestational days (GDs) 6 to 15. Control groups received normal saline or paraffin as solvents of crocin and safranal. Dams were dissected on GD18 and embryos were collected. Routine maternal and fetal parameters were recorded. Macroscopic observation of external malformations was also performed. Fetuses were then selected for double skeletal staining with alizarin red and alcian blue. All experimental groups caused significant decrease in length and weight of fetuses when compared with the control groups and revealed malformations such as minor skeletal malformations, mandible and calvaria malformations, and growth retardation. Minor skeletal malformations were the most commonly observed abnormality, which were statistically significant when compared with the control groups (p < 0.05). The severities of malformations were comparable in the crocin- and safranal-treated groups. This study suggests that crocin or safranal can induce embryonic malformations when administered in pregnant mice. Due to the wide use of saffron, further elaborate studies to understand the malformation mechanisms of these ingredients are recommended.

Pathogenesis of Pregabalin-Induced Limb Defects in Mouse Embryos.

PURPOSE: It is known that antiepileptic drugs might adversely affect neuronal function and thus influence brain development. However, we have reported that limb deformities are one of the most prominent disturbances caused by pregabalin (PGB) in the developing embryo. The aim of this work is to gain a better understanding of possible molecular mechanisms behind the musculoskeletal injuries and limb deformities associated with PGB. METHODS: Pregnant mice divided into four groups. Each mouse received an intraperitoneal injection (IP) of 0, 20 (group I), 40 (group II) or 80 (group III) mg/kg/day of PGB during the organogenesis period. On gestational day 18, embryos were separated and their limbs were dissected. Levels of apoptotic proteins were analyzed by Western blotting. To establish whether apoptosis is present in the limbs, the specimens were examined by TUNEL. Pathological findings were also reported as a score ranging from 1 to 3 based on the level of differentiation. RESULTS: Western blot analysis demonstrated that PGB in all PGB-treated groups significantly upregulated the levels of cleaved caspase-3, 8 and 9. Also, the results showed that PGB exposure increased the percentage of TUNEL positive cells in different limb tissues especially the mesenchymal tissue. The histopathological findings revealed that PGB administration to pregnant mice inhibited limb tissue differentiation, albeit to varying degrees. CONCLUSIONS: The result of our study revealed that apoptosis and inhibition of limb tissue differentiation play an important role in the pathogenesis of PGB-induced limb malformations. Both intrinsic and extrinsic caspase-dependent pathways of cell death are important in mediating the abnormal limb development triggered by insult with the PGB. Evaluating the effect of PGB on molecules involved in the cross-talk between intrinsic and extrinsic apoptotic pathways and cell adhesion, migration, proliferation, and differentiation during embryonic development can further help to identify and clarify the involved mechanisms.

Treatment of high dose of intravenous midazolam abuse: a case report.

This study reports a rare case of high-dose midazolam abuse and Munchausen Syndrome. A 48-year-old female physician was referred by a psychiatrist to the Toxicology Department of Imam Reza Hospital for abstaining from 300 mg/day of parenteral midazolam. She had mimicked the symptoms of Crohn's disease; therefore, she had undergone 15 colonoscopies and 40 times MRI or CT scan, all of which were normal. Six months earlier, she had switched oral methadone to 30 mg/day of intravenous midazolam. She also had several skin lesions on injection sites that she considered pyoderma gangrenosum. When the total daily dose of intravenous midazolam was switched to oral bioequivalence of clonazepam, she could not tolerate withdrawal (Clinical Institute Withdrawal Assessment Scale-Benzodiazepines = 68). Therefore, she received midazolam again as a continuous intravenous infusion. Within 7 days, the whole dose was replaced by the bioequivalence oral dose of clonazepam. She was also treated with carbamazepine and cognitive behavior therapy. Afterward, she was transferred to the psychiatric ward for further psychiatric treatment. Dependency on a high dose of midazolam could be treated by tapering off the long-acting benzodiazepine.

Role of orphan G-protein coupled receptors in tissue ischemia: A comprehensive review.

Ischemic events lead to many diseases and deaths worldwide. Ischemia/reperfusion (I/R) occurs due to reduced blood circulation in tissues followed by blood reflow. Reoxygenation of ischemic tissues is characterized by oxidative stress, inflammation, energy distress, and endoplasmic reticulum stress. There are still no adequate clinical protocols or pharmacological approaches to address the consequences of I/R damage. G protein-coupled receptors (GPCRs) are important therapeutic targets. They compose a large family of seven transmembrane-spanning proteins that are involved in many biological functions. Orphan GPCRs are a large subgroup of these receptors expressed in different organs. In the present review, we summarized the literature regarding the role of orphan GPCRs in I/R in different organs. We focused on the effect of these receptors on modulating cellular and molecular processes underlying ischemia including apoptosis, inflammation, and autophagy. The study showed that GPR3, GPR4, GPR17, GPR30, GPR31, GPR35, GPR37, GPR39, GPR55, GPR65, GPR68, GPR75, GPR81, and GPR91 are involved in ischemic events, mainly in the brain and heart. These receptors offer new possibilities for treating I/R injuries in the body.

Evaluation of Melatonin and its Nanostructures Effects on Skin Disorders Focused on Wound Healing.

Skin is the largest organ of the human body functioning as a great primitive defensive barrier against different harmful environmental factors. However, it is damaged through varying injuries such as different wounds, burns, and skin cancers that cause disruption in internal organs and essential mechanisms of the body through inflammation, oxidation, coagulation problems, infection, etc. Melatonin is the major hormone of the pineal gland that is also effective in skin disorders due to strong antioxidant and anti-inflammatory features with additional desirable antiapoptotic, anti-cancer, and antibiotic properties. However, melatonin characteristics require improvements due to its limited water solubility, halflife and stability. The application of nanocarrier systems can improve its solubility, permeability, and efficiency, as well as inhibit its degradation and promote photostability. Our main purpose in the current review is to explore the possible role of melatonin and melatonin-containing nanocarriers in skin disorders focused on wounds. Additionally, melatonin's effect in regenerative medicine and its structures as a wound dressing in skin damage has been considered.

Therapeutic potential of Capparis spinosa in experimental model of acute acetic acid-induced colitis: Anti-inflammatory and antioxidant effects.

Introduction: This study examined the anti-inflammatory and antioxidant properties of Capparis spinosa L. (caper) in order to determine its medicinal potential in the treatment of acute colitis. Method: Sixty male rats were divided into six groups. After the experimental period, distal colonic extension was collected for determination of colonic damage, oxidative stress markers, along with antioxidant markers. The impact of altered levels of inflammatory cytokines in colon tissues on the underlying mechanisms examined. Results: The results showed that administering different doses of caper led to significant decreases in TNF-α and IL-6 levels when compared to the control colitis group (p < 0.001). Caper treatment effectively lowered elevated oxidative stress factors (MDA, NO, and MPO) compared to the control colitis group (p < 0.001). Caper treatment resulted in a significant increase in antioxidant factors (CAT, SOD, and GSH) compared with the control colitis group (p < 0.001).Significant improvements in tissue repair were observed in caper-treated groups compared to positives and control colitis (p < 0.001). Conclusion: The study highlights caper may be useful in the treatment of acute colitis due to its ameliorative effects on inflammation, oxidative stress, and tissue repair.

Recent Advances in the Treatment of Spinal Cord Injury.

Spinal cord injury (SCI) is a complex, multifaceted, progressive, and yet incurable complication that can cause irreversible damage to the individual, family, and society. In recent years strategies for the management and rehabilitation of SCI besides axonal regeneration, remyelination, and neuronal plasticity of the injured spinal cord have significantly improved. Although most of the current research and therapeutic advances have been made in animal models, so far, no specific and complete treatment has been reported for SCI in humans. The failure to treat this complication has been due to the inherent neurological complexity and the structural, cellular, molecular, and biochemical characteristics of spinal cord injury. In this review, in addition to elucidating the causes of spinal cord injury from a molecular and pathophysiological perspective, the complexity and drawbacks of neural regeneration that lead to the failure in SCI treatment are described. Also, recent advances and cutting-edge strategies in most areas of SCI treatment are presented.

Buprenorphine induced opioid withdrawal syndrome relieved by adjunctive Magnesium: A clinical trial.

INTRODUCTION: Precipitated opioid withdrawal syndrome (OWS) is a severe and intolerable situation that may occur by a pharmaceutical agent. Reactivation of inhibited N-methyl-d-aspartate (NMDA) receptor in person with prolonged opioid use can led to severe OWS. We conducted a double-blind, randomized clinical trial to assess the effect of magnesium sulfate (MGSO4) as an NMDA receptor antagonist on OWS. MATERIALS AND METHODS: The study randomly divided forty patients with precipitated OWS due to partial agonist (buprenorphine) use referred to the emergency unit of Toxicology Department of Mashhad University of Medical Sciences, Iran; into two groups. The control group received conventional therapies, including clonidine 0.1 mg tablet each hour, intravenous infusion of 10 mg diazepam every 30 min, and IV paracetamol (Acetaminophen) 1 g, while the intervention group received 3 g of MGSO4 in 20 min and then 10 mg/kg/h up to 2 h, in addition to the conventional treatment. The clinical opiate withdrawal scale (COWS) evaluated OWS at the start of the treatment, 30 min, and 2 h later. RESULTS: Both groups had similar demographic, opiate types, and COWS severity at the start of the intervention. COWS was lower in the intervention than the control group at 30 min (11.20 ± 2.86 and 14.65 ± 2.36, respectively, P = 0.002) and at 2 h (3.2 ± 1.61 and 11.25 ± 3.27, respectively, P < 0.001) after treatment. The intervention group received lesser doses of clonidine (0.12 ± 0.51 and 0.17 ± 0.45 mg, P = 0.003) and Diazepam (13.50 ± 5.87, 24.0 ± 6.80 mg, P = 0.001) than the control group. Serum magnesium levels raised from 1.71 ± 0.13 mmol/L to 2.73 ± 0.13 mmol/L in the intervention group. CONCLUSION: Magnesium can significantly reduce the severity of OWS. Additional studies are required to confirm these results.

Effect of oral naloxone on opioid-induced constipation in methadone maintenance treatment patients, a double-blind, placebo-control, clinical trial.

BACKGROUND: Opioid-induced constipation (OIC) is the most prevalent side effect of methadone maintenance therapy (MMT). Naloxone could reduce the OIC. METHOD: Fifty-six MMT cases (< 75 mg/day methadone, > 3 months) were entered randomly into four groups of a trial. They received placebo or naloxone tablets (0.5, 2, or 4 mg/day) once a day for 2 weeks. They continued their conventional laxative. Their constipation and opiate withdrawal (OWS) were evaluated by the Bristol Stool Form Scale (stool consistency and frequency), Patient Assessment of Constipation Symptoms (PAC-SYM) questionnaire, Constipation Scoring System (CSS), and the Subjective Opiate Withdrawal Scale (SOWS) before starting treatment and at the end of the first and second weeks. RESULTS: The dose of 4 mg/day naloxone was excluded from the study due to severe OWS. The precipitants of groups had similar ages, methadone dose and duration, laxative use, and constipation scores at the start of the trial. However, 2 mg of naloxone could change the stool consistency (PV = 0.0052) and frequency (P = 0.0133), 0.5 mg/day dose only improved the stool consistency (P = 0.0016). The patients' CSS and PAC-SYM scores were reduced by naloxone after the 1st week of treatment. However, there was no significant difference in the mean score of SOWS at different assessment times and groups. Also, 3 and 4 cases of 0.5 and 2 mg/day groups, respectively, withdrew from the study due to OWS. CONCLUSION: Oral naloxone at doses of 0.5 and 2 mg/day was significantly more effective than placebo on OIC in MMT. However, the dose of 4 mg induced intolerable OWS.