Evaluation of three-year neurodevelopmental outcomes in infants prenatally exposed to substance use

INTRODUCTION

Prenatal exposure to substance use is associated with long-term deficits in the neurodevelopment of children. The objective was to investigate the association between cognitive, motor, and language neurodevelopment at three years of age in infants prenatally exposed to substance use.

MATERIAL AND METHODS

A prospective matched case-control study was conducted. Biomarkers of fetal exposure were measured in meconium samples. The Bayley Scales of Infant and Toddler Development (BSID-III) were used to calculate neurodevelopment scores.

RESULTS

32 non-exposed and 32 exposed infants were evaluated, of which 16 were exposed to cannabis, 8 to ethanol, 2 to cocaine and 6 to more than one substance. Normal BSID-III scores ≥85 in all domains, were detected in 23 exposed infants to any substance and 29 infants non-exposed. Neurodevelopmental delay was detected in the language domain, specifically in male infants exposed to cannabis. Two infants exposed to cannabis had a severe developmental delay (score<70). Infants exposed to any substance obtained significantly lower total scores than control infants in all domains. Infants exposed to cannabis obtained significantly lower composite scores in the cognitive and motor domains. Infants exposed to more than one substance had lower scores in motor skills. By gender, only males exposed obtained significantly lower composite scores than non-exposed males in the cognitive domain.

CONCLUSIONS

The most common and severe neurodevelopmental delay at 36 months was detected in the domain of language in male infants prenatally exposed to cannabis. Neurodevelopmental disorders detected can enable an early intervention and plan therapeutic strategies.

Clinical features and risk factors associated with prenatal exposure to drugs of abuse

INTRODUCTION

Early identification of neonates exposed to drugs of abuse during pregnancy allows a more precise clinical management.

OBJECTIVES

To describe the clinical characteristics and to identify risk factors associated with the early detection of neonates exposed to drugs of abuse in a Neonatal Intermediate and Intensive Care Unit.

METHODS

Prospective observational study of neonates with and without clinical suspicion of prenatal exposure to drugs of abuse. Meconium was analyzed using standard chromatographic techniques. Univariate and multivariate statistical analyzes were performed.

RESULTS

372 neonates were included. Exposure to drugs of abuse was detected in 49 (13.2%) cases: in 41 (83.7%) one drug and in 8 (16.3%) more than one. Somatometry at birth revealed: a) lower length percentile in those exposed to some drug, more than one and cannabis; b) lower weight percentile in those exposed to cannabis and of these compared to those exposed to alcohol. In neonates older than 34 pregnancy weeks (PW): a) lower length percentile in those exposed to any substance; b) lower percentile of length and weight in exposed to more than one. The most clinically relevant independent risk factors useful to detect cases of prenatal exposure to drugs of abuse were (Odds ratio (95% CI)): reason for admission other than prematurity (5.52 (2.55-1.93)), length percentile less than 33 (1.95 (1.05-3.60) and 2.14 (1.04-3.40) in older than 34 PW) and social dystocia/uncontrolled pregnancy in older than 34 PW (4.47 (1.03-19.29)).

CONCLUSIONS

There are somatometric alterations and risk factors that can help in the early detection of neonates exposed to drugs of abuse. The somatometric alterations identified can be useful to extend the differential diagnosis of these alterations and to study their causes.

Diminished Consciousness in a Woman Following an Unsuspected Scopolamine Overdose

Scopolamine is used clinically, but it is also used as a recreational drug and as an incapacitating drug, in sexual crimes and robberies. In this paper, the authors report the case of a woman with a diminished consciousness following an unsuspected overdose with scopolamine and review published articles on scopolamine poisoning that included concentrations in biological samples. Scopolamine was identified in the patient's serum and urine samples collected 1 h post-admission to intensive care unit at concentrations of 8.4 ng/mL and 62,560 ng/mL (169,539 ng/mg creatinine), respectively. In non-fatal cases, the median [interquartile range] of serum scopolamine levels was 1.9 [2.1] ng/mL. The serum concentration found in our case would explain the abrupt clinical presentation suffered by the patient. Scopolamine in urine could be detected up to 48 h after admission. This report illustrates that broad toxicology screening, including scopolamine, should be considered when patients with diminished consciousness are attended after ruling out infection or cerebrovascular disease. This can play an important role in identifying this potentially life-threatening etiology.

Role of Neonatal Biomarkers of Exposure to Psychoactive Substances to Identify Maternal Socio-Demographic Determinants

Simple Summary

The rapid identification of newborns exposure to psychoactive drugs allows an appropriate clinical care. This study tried to identify maternal profiles that help to identify newborns exposed to psychoactive drugs during pregnancy. Mothers were interviewed using a questionnaire. The biomarkers of fetal exposure were measured in meconium samples. Statistical analysis was performed to identify the maternal characteristics that were most likely to be associated with drug use during pregnancy. Of a total of 372 mothers, 49 (13.2%) tested positive for psychoactive drugs use: 24 (49.0%) for cannabis, 11 (22.5%) for ethyl glucuronide, six (12.2%) for cocaine, and eight (16.3%) for more than one psychoactive substance. The maternal characteristics that most likely identify substance use during pregnancy are: maternal age < 24 years, lack of pregnancy care, single-mother families, and active tobacco smoking. The profiles of prenatal maternal exposure identified in a clinical setting can be used to request specific detection tests for identifying newborns exposed to these drugs.

Abstract

Background: The accurate assessment of fetal exposure to psychoactive substances provides the basis for appropriate clinical care of neonates. The objective of this study was to identify maternal socio-demographic profiles and risk factors for prenatal exposure to drugs of abuse by measuring biomarkers in neonatal matrices. Methods: A prospective, observational cohort study was completed. Biomarkers of fetal exposure were measured in meconium samples. The mothers were interviewed using a questionnaire. Univariate and multivariate logistic regression analyses were performed. Results: A total of 372 mothers were included, 49 (13.2%) testing positive for psychoactive substances use: 24 (49.0%) for cannabis, 11 (22.5%) for ethyl glucuronide, six (12.2%) for cocaine, and in eight (16.3%) more than one psychoactive substance. Mothers who consumed any psychoactive substance (29.7 ± 6.6 years) or cannabis (27.0 ± 5.7 years) were younger than non-users (32.8 ± 6.2 years, p < 0.05). Cocaine (50.0% vs. 96.9%, p < 0.05) and polydrug users (37.5% vs. 96.9%, p < 0.05) showed a lower levels of pregnancy care. Previous abortions were associated with the use of two or more psychoactive substances (87.5% vs. 37.8%, p < 0.05). Single-mother families (14.3% vs. 2.5%, p < 0.05) and mothers with primary level education (75.5% vs. 55.1%, p < 0.05) presented a higher consumption of psychoactive substances. Independent risk factors that are associated with prenatal exposure include: maternal age < 24 years (odds ratio: 2.56; 95% CI: 1.12–5.87), lack of pregnancy care (odds ratio: 7.27; 95%CI: 2.51–21.02), single-mother families (odds ratio: 4.98; 95%CI: 1.37–8.13), and active tobacco smoking (odds ratio: 8.13; 95%CI: 4.03–16.43). Conclusions: These results will allow us to develop several risk-based drug screening approaches to improve the early detection of exposed neonates.

[Clinical features and risk factors associated with prenatal exposure to drugs of abuse]

INTRODUCTION

Early identification of neonates exposed to drugs of abuse during pregnancy allows a more precise clinical management.

OBJECTIVES

To describe the clinical characteristics and to identify risk factors associated with the early detection of neonates exposed to drugs of abuse in a Neonatal Intermediate and Intensive Care Unit.

METHODS

Prospective observational study of neonates with and without clinical suspicion of prenatal exposure to drugs of abuse. Meconium was analyzed using standard chromatographic techniques. Univariate and multivariate statistical analyzes were performed.

RESULTS

372 neonates were included. Exposure to drugs of abuse was detected in 49 (13.2%) cases: in 41 (83.7%) one drug and in 8 (16.3%) more than one. Somatometry at birth revealed: a) lower length percentile in those exposed to some drug, more than one and cannabis; b) lower weight percentile in those exposed to cannabis and of these compared to those exposed to alcohol. In neonates older than 34 pregnancy weeks (PW): a) lower length percentile in those exposed to any substance; b) lower percentile of length and weight in exposed to more than one. The most clinically relevant independent risk factors useful to detect cases of prenatal exposure to drugs of abuse were (Odds ratio (95% CI)): reason for admission other than prematurity (5.52 (2.55-1.93)), length percentile less than 33 (1.95 (1.05-3.60) and 2.14 (1.04-3.40) in older than 34 PW) and social dystocia/uncontrolled pregnancy in older than 34 PW (4.47 (1.03-19.29)).

CONCLUSIONS

There are somatometric alterations and risk factors that can help in the early detection of neonates exposed to drugs of abuse. The somatometric alterations identified can be useful to extend the differential diagnosis of these alterations and to study their causes.

Post-mortem toxicology in the diagnosis of sudden death in young and middle-aged victims

OBJECTIVE

We aimed to investigate the impact of the toxicological results found in cases of sudden death (SD) and to correlate the clinical, autopsy and genetic findings with the toxicology results.

MATERIALS AND METHODS

Consecutive SD in people aged between 16 and 50 years with medico-legal autopsies and toxicology studies were included over a 3-year period. The comparison between the toxicological data and demographic characteristics, clinical circumstances, autopsy, and genetic results were taken into account.

RESULTS

101 cases were finally included. They were predominately males (84%) and the mean age was 39.8 years. 52 (51.5%) cases had positive toxicological findings and in 25 cases (24.8%), toxic compounds were considered the first cause of death. Ethanol was the most frequently identified agent (69%), following by licit drugs (56%) and drugs of abuse (39%). Cases with positive toxicology were younger than those with negative results (37.9±9.1 vs. 41.9±7.8; p=0.02). Patients with more than 3 comorbidities showed an association with positive toxicological results (n=14 vs. n=3; p=0.017). The genetic study was performed in 70 (69.3%) SD cases. We identified pathogenic or likely pathogenic variants in 17.1% cases and uncertain significance variants in 42.8% cases. 58% of these variants were probably related to the cause of death.

CONCLUSIONS

A large fraction of SD victims had positive toxicological findings and a quarter of deaths were directly caused by toxic substances. The identification of the factors that trigger SD provides a good approach to contribute in avoiding future episodes.

Detectability of Dissociative Psychoactive Substances in Urine by Five Commercial Phencyclidine Immunoassays

Methoxetamine (MXE) and the arylcyclohexylamines 3-methoxy-PCP (3-MeO-PCP) and 4-methoxy-PCP (4-MeO-PCP) are substituted analogs of the dissociative psychoactive substances ketamine and phencyclidine (PCP), respectively. They have emerged on the new psychoactive substances (NPS) market as legal alternatives to these classically banned dissociatives. Little data has been published regarding the cross-reactivity of these NPS in PCP immunoassays (IAs). The aim of this work was to explore the possibilities of detecting 3-MeO-PCP, 4-MeO-PCP, MXE and ketamine in commercial IAs for PCP. The cross-reactivity study was performed in five different PCP IAs using urine-free, spiked samples and urine samples obtained from two 3-MeO-PCP overdose cases. 3-MeO-PCP and 4-MeO-PCP showed cross-reactivity (ranging from 1–143%) in all PCP IAs evaluated. MXE only showed very weak cross-reactivity (ranged from 0.04 to 0.25%) and ketamine was not detected in any PCP IA evaluated. Urine samples from the two overdose cases were positive for PCP in all IAs evaluated. The commercial PCP IAs evaluated exhibited utility as rapid, preliminary screening techniques for 3-MeO-PCP and 4-MeO-PCP, but not for ketamine. The low reactivity of MXE limits its detectability in the PCP IAs evaluated.

Building Bridges between Clinical and Forensic Toxicology Laboratories

BACKGROUND

Clinical and forensic toxicology can be defined as two disciplines involving the detection, identification and measurement of xenobiotics in biological and non-biological samples to assist in the diagnosis, treatment, prognosis and prevention of poisonings and to disclose causes and contributory causes of fatal intoxications, respectively.

OBJECTIVE

This article explores the close connections between clinical and forensic toxicology in overlapping areas of interest.

METHODS

An update has been carried out of the following seven areas of interest in analytical toxicology: doping control, Sudden Cardiac Death (SCD), brain death, Sudden Infant Death Syndrome (SIDS) and Munchausen Syndrome by Proxy (MSBP), prenatal exposure to drugs and Fetal Alcohol Syndrome (FAS), Drug-Facilitated Crimes (DFC) and intoxications by new psychoactive substances (NPS).

RESULTS

While issues such as SCD, SIDS or doping control are investigated mainly in forensic laboratories, others such as prenatal exposure to drugs or FAS are mainly treated in clinical laboratories. On the other hand, areas such MSBP, DFC or the intoxications by NPS are of interest in both laboratories. Some of these topics are initially treated in hospital emergency departments, involving clinical laboratories and sometimes lately derived to forensic laboratories. Conversely, cases with initial medicallegal implications and fatalities are directly handled by forensic toxicology, but may trigger further studies in the clinical setting.

CONCLUSION

Many areas of common interest between clinical and forensic laboratories are building bridges between them. The increasing relationships are improving the growth, the reliability and the robustness of both kinds of laboratories.

Quantification of Methamphetamine «Shabu» in Biological Matrices to Detect Prenatal Exposure: A Case Report and a Literature Review

BACKGROUND

Methamphetamine misuse represents an increasing global public health problem. Its consumption during pregnancy becomes a relevant issue, since it has clinical consequences for the child's health and the pregnant woman. Despite this, there are only few data in the literature that include analytical results in the matrices used to detect prenatal exposure.

OBJECTIVES

1) Present a case report of prenatal methamphetamine exposure with toxicological analytical confirmation in biological matrices; and 2) Perform a compilation of prenatal methamphetamine exposure studies and case reports which include toxicological analytical results.

METHODS

Prenatal methamphetamine exposure was confirmed using a traditional "screen with reflex" approach. Methamphetamine and amphetamine were quantified in urine, meconium and hair samples of the neonate and mother by gas chromatography-mass spectrometry. Also, a detailed revision of the existent literature that provides information on the analytical toxicology results has been included.

RESULTS

In the neonatal biological matrices test results of methamphetamine/amphetamine were: urine 2,966.43/1,638.71 ng/mL, meconium 1,450/&lt;0.1 ng/g and hair 36.54/9.66 ng/mg. In the maternal biological matrices, test results were: urine 13,393.89/3,074.95 ng/mL and hair 11.29/3.37 ng/mg (0-3 cm), 4.68/2.58 (3-6 cm), 6.43/3.13 ng/mg (6-9 cm) and 4.72/2.49 ng/mg (9-12 cm). These results confirm a recent and continued regular substance use throughout pregnancy including delivery.

CONCLUSION

The data provided will be useful for clinical purposes to improve the diagnostic and follow- up of acute and chronic intoxications. Additionally, results will be used to support interpretations in the field of forensic and legal medicine.

2,4-Diamino-N10-methylpteroic acid (DAMPA) crystalluria in a patient with osteosarcoma treated with carboxypeptidase-G2 rescue after high-dose methotrexate-induced nephrotoxicity

BACKGROUND

High-dose methotrexate (HDMTX) therapy is a key component of many chemotherapy protocols. However, some patients develop HDMTX-induced nephrotoxicity. Carboxypeptidase-G2 (CPDG2) hydrolyses MTX into 2,4-diamino-N10-methylpteroic acid (DAMPA) and glutamic acid, and is used as a rescue agent in patients with nephrotoxicity and delayed elimination. Despite the frequency of HDMTX-induced renal injury, crystalluria is uncommon. Furthermore, crystals are rarely identified by conventional chemical methods.

OBJECTIVE

To determine the composition of crystalluria in a patient with osteosarcoma who was treated with CPDG2.

METHODS

Crystalluria was evaluated by optical microscopy, and chemical identification was performed by Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and Orbitrap™ high-resolution mass spectrometry (HRMS).

RESULTS

The HRMS spectra of the patient's urine sediment showed a main peak at m/z 326.13, corresponding to the molecular mass of DAMPA [(C₁₅H₁₅O₂N₇) + H⁺]. The FT-IR spectral patterns of the sediment and DAMPA were not identical. SEM was unable to identify the crystal.

CONCLUSION

DAMPA crystalluria was identified by Orbitrap™ HRMS in a patient treated with CPDG2 after HDMTX nephrotoxicity. This case reinforces the need to implement adequate measures to prevent nephrotoxicity. In cases of HDMTX-induced nephrotoxicity, urine sediment analysis should be requested.

Cross-Reactivity of Pantoprazole with Three Commercial Cannabinoids Immunoassays in Urine

Pantoprazole is a frequently prescribed proton pump inhibitor (PPI) commonly utilized in the management of gastrointestinal symptoms. Few substances have proved to cause a false-positive cannabinoid urine screen. However, a case of false-positive urine cannabinoid screen in a patient who received a pantoprazole dose has been recently published. The purpose of this study was to determine the potential cross-reactivity of pantoprazole in the cannabinoid immunoassays: Alere Triage® TOX Drug Screen, KIMS® Cannabinoids II and DRI® Cannabinoids Assay. Drug-free urine to which pantoprazole was added up to 12,000 μg/mL produced negative results in the DRI® Cannabinoids and KIMS® Cannabinoids II. Alere Triage® TOX Drug Screen assay gave positive results at pantoprazole concentrations higher than 1,000 μg/mL. Urine samples from 8 pediatric patients were collected at the beginning of their pantoprazole treatment. Alere Triage® TOX Drug Screen assay produced positive test results in all patient samples and KIMS® Cannabinoids II immunoassay produced positive test results in one patient sample. None patient sample gave a false-positive result when analyzed by the DRI® Cannabinoids Assay. Our findings demonstrate that some cannabinoids immunoassays are susceptible to cross-reaction errors resulting from the presence in urine of pantoprazole and the resulting metabolism of the parent drug. Clinicians should be aware of the possibility of false-positive results for cannabinoids after a pantoprazole treatment.

Pharmacology and Literature Review Based on Related Death and Non-Fatal Case Reports of the Benzofurans and Benzodifurans Designer Drugs

BACKGROUND

Benzofurans and benzodifurans are two groups of psychoactive substances that had originally been synthesized for research purpose. Benzofurans' structure is quite similar to the known recreational drug 3,4-methylenedioxymethamphetamine together with its active metabolite 3,4-methylenedioxyamphetamine. Benzodifurans are closely related to phenethylamines, but have more hallucinogens effects and much longer duration of action. This study aims to review the accessible evidence-based literature on benzofurans and benzodifurans pharmacology and toxicology.

METHODS

A literature search on benzofurans and benzodifurans has been conducted using PubMed. We reviewed articles up to February 2017 and also included data from various governmental websites and discussion groups.

RESULTS

This review describes the emergent literature that illustrates the chemical composition of these drugs, patterns of use, pharmacology, toxicology, desired and clinical effects, and treatments of patients. It also provides a compilation of case reports.

CONCLUSION

The knowledge regarding usage prevalence, pharmacokinetic and pharmacodynamic profiles, acute toxic effects, the effects desired on patients and drug related mortality attributed to these drugs is still limited. Nowadays, there are no specific guidelines available to treat benzofurans or dibenzofurans intoxications. For that reason, clinical effects should be the base of treatment. Backing exposures analytically confirmed in clinical and forensic cases and reported clinical effects need to be combined with these compounds while monitoring its prevalence.

Acute intoxication caused by synthetic cannabinoids 5F-ADB and MMB-2201: A case series

Synthetic cannabinoids are relatively new substances of abuse. Recently, abuse of synthetic cannabinoids has been increasingly reported in the lay press and medical literature. When new compounds are introduced, their use is initially not restricted by prohibition therefore their consumption cannot be verified by standard drug tests. The use of these compounds among adolescents and young adults is constantly growing, making it important for emergency services to be familiar with the signs and symptoms of intoxication present. Overdose and chronic use of these substances can cause adverse effects including altered mental status, tachycardia, and loss of consciousness. Here, we report five cases of acute intoxication by synthetic cannabinoids 5F-ADB and MMB-2201 with analytical confirmation.

Phytotherapy in a rat model of hyperoxaluria: the antioxidant effects of quercetin involve serum paraoxonase 1 activation

Serum paraoxonase 1 (PON1) has been reported to be an important contributor to the antioxidant and anti-inflammatory activities of HDL, avoiding LDL oxidation. The activity of this enzyme is reduced in patients with renal insufficiency, caused by elevated oxidative stress and disturbances of apolipoprotein metabolism. Therapeutic utilization of antioxidants to control renal oxidative stress may be an effective therapy in renal protection. The aim was to investigate the protective effects of several antioxidant compounds against the oxidative stress associated to renal failure induced by ethylene glycol (EG), focusing on the possible role of serum PON1 activity. Fifty-four male Wistar rats were randomly assigned to six groups (n = 9): an untreated control (C) group, an EG-treated group, a catechin (CAT)-treated group, an epicatechin (EPI)-treated group, a quercetin (QUE)-treated group and a folk herbal extract (FHE)-treated group. After 16 d of treatment, calcium oxalate lithiasis was induced in the rats using EG. After eight days (treatment + EG), the animals were sacrificed. EG treatment impaired kidney composition, increased oxidative damage, and decreased serum paraoxonase and arylesterase activities. CAT, QUE and the FHE Fagolitos improved oxidative status by enhancing antioxidant defenses - superoxide dismutase and PON1 activities - and reducing oxidative damage, thus reinforcing the idea of a possible role of PON1 in the protective effects of QUE against the deleterious consequences of oxidative stress in kidney.

Urinary pH and renal lithiasis

Formation of calcium oxalate crystals, either as monohydrate or dihydrate, is apparently unrelated to urinary pH because the solubilities of these salts are practically unaltered at physiologic urinary pH values. However, a urinary pH <5.5 or >6.0 may induce uric acid or calcium phosphate crystals formation, respectively, which under appropriate conditions may induce the development of the calcium oxalate calculi. We assessed the relationship between the urinary pH and the formation of different types of calculi. A retrospective study in 1,478 patients was done. We determined the composition, macrostructure, and microstructure of the calculi and the urinary pH, 50.9% of calcium oxalate monohydrate unattached calculi were present in patients with urinary pH <5.5. We found that 34.1 and 41.5% of calcium oxalate dihydrate calculi were present in patients with urinary pH <5.5 and >6.0, respectively. Infectious calculi were found primarily in patients with urinary pH >6.0 (50.7%). Only calcium oxalate monohydrate papillary calculi were associated with urinary pH between 5.5 and 6.0 (43.1%). Urine of pH <5.5 shows an increased capacity to develop uric acid crystals, which can act as a heterogeneous nuclei of calcium oxalate crystals. In contrast, urine of pH >6.0 has an increased capacity to develop calcium phosphate crystals, which can act as a heterogeneous nuclei of calcium oxalate crystals. Oxalate monohydrate papillary calculi were associated to pH between 5.5 and 6.0 because the injured papilla acts as a heterogeneous nucleant. Consequently, measurement of urinary pH may be used to evaluate the lithogen risk of given urine.

Origin and types of calcium oxalate monohydrate papillary renal calculi

OBJECTIVES

Subepithelial hydroxyapatite calcification of renal papilla is thought to be involved in the formation of calcium oxalate monohydrate (COM) papillary calculi. To assess the mechanism of formation, we sought to correlate the fine structure of papillary renal calculi with specific pathophysiologic conditions and urinary alterations.

METHODS

The study included 831 COM papillary renal calculi with established fine inner structures. A total of 24 patients with chronic stone formation were randomly selected, and their urine was collected and analyzed. The case history and lifestyle habits of these patients were obtained.

RESULTS

The 831 papillary calculi could be classified into 1 of 4 main groups. Type I included small calculi in which COM columnar crystals begin to develop in the concave zone in close contact with papillary tissue. Type II calculi contained a hydroxyapatite core located in or near the concave zone. Type III consisted of calculi that developed on the tip of the papillae and in the concave zone, containing hydroxyapatite, calcified tissue, and calcified tubules. Type IV consisted of papillary calculi in which the core, which is situated near, but not in, the concave zone, is formed by intergrown COM crystals and organic matter. Many factors, including urinary alterations (eg, hyperoxaluria), associated diseases (eg, hypertension, diabetes), and consumption or exposure to cytotoxic substances (eg, analgesic abuse) were associated with these types of calculi.

CONCLUSIONS

Our findings have indicated that injury is the first cause of papillary COM calculus formation, with the location of the injury determining the morphology of the resulting calculus.

Phytotherapy and renal stones: the role of antioxidants. A pilot study in Wistar rats

Since ancient times, various herbal preparations have been used in renal lithiasis therapy, but conclusive scientific data on their therapeutic effects and efficacy are not available. To address this issue, the present study evaluated the antilithiasic activity of a traditional Mallorcan herbal preparation, and compared its effects with those of the antioxidant flavonoids, catechin and epicatechin. Thirty-six male Wistar rats were assigned randomly to four groups (n = 9): a control group, a catechin (CAT) treatment group, an epicatechin (EPI) treatment group, and a group treated with a folk herbal extract (FHE). After 16 days of treatment, calcium oxalate lithiasis was induced in the rats using ethylene glycol. After 8 days (treatment + ethylene glycol), 24-h rat urine was collected, the animals were sacrificed and their kidneys were removed for histological and chemical analysis. The calcium concentration in kidney tissue was significantly lower in the CAT-treated (2.4 +/- 0.3 mg/g), EPI-treated (1.8 +/- 0.3 mg/g) and FHE-treated (2.1 +/- 0.3 mg/g) groups, than in the control group (5.4 +/- 1.4 mg/g). Examination of paraffin-embedded kidney sections showed that control group rats had the greatest amount of calcification. There were no significant differences between control and treated groups with respect to urinary calcium, magnesium, oxalate and citrate concentrations. These results demonstrate the ability of herbal preparations and antioxidants to prevent the development of papillary and intratubular calcification in the kidney.