Phenacetin abuse: a review

Analysis of umbilical cord tissue as an indicator of in utero exposure to toxic adulterating substances

In utero drug exposure is a significant public health threat to the well-being and normal development of the neonate. Recently, testing of umbilical cord tissue (UCT) has been employed to measure illicit drug exposure, as drugs used by the mother during the third trimester may be retained in the UCT. Focus has also been given to potential adverse health effects among drug users, resulting from exposure to pharmacologically active adulterants and cutting agents in the street drug supply. The in utero effects of these substances have not been well studied in humans, nor has their presence been demonstrated as a means for assessing adverse health effects in the neonate. Here, we describe the application of a novel test method to analyze UCT for the presence of more than 20 common adulterating/cutting substances via LC/Q-TOF. In total, 300 de-identified UCT samples were analyzed-all had previously tested positive for cocaine or opiates. Generally, the positivity rates of individual compounds were similar between the Cocaine and Opiates Subgroups, apart from levamisole, xylazine, dipyrone (metabolites), and promethazine. Many of the adulterants used in the street drug supply do have legitimate medicinal/therapeutic uses, including several of the compounds most frequently detected in this study. Caffeine and lidocaine were the most frequently identified compounds both individually (>70% each) and in combination with each other. Alternatively, levamisole, an adulterant with no legitimate therapeutic use, was present in 12% of cases. Importantly, this data demonstrates that the detection of traditional drugs of abuse may serve as indicators of potential in utero exposure to toxic adulterating substances during gestation. While there is cause for concern with respect to any unintentional drug exposure, illicit drug use during pregnancy, including uncontrolled dosing, poly-adulterant consumption, and the interactions of these drug mixtures, produces a significant public health threat to the neonate which warrants further study.

N-(4-Ethoxy-2,5-dinitrophenyl)acetamide

In the title compound, C10H11N3O6, the torsion angles about the bonds to the benzene ring are less than 4°, except for the nitro groups, which are twisted out of the ring plane by 25.27 (3) and 43.63 (2)°. The N—H group forms a bifurcated hydrogen bond, with an intramolecular component to a nitro group O atom and an intermolecular component to the other nitro group, thereby forming chains propagating in the [010] direction. Several weak C—H...O interactions are also present.

Status of non-steroidal anti-inflammatory drugs use and its association with chronic kidney disease: a cross-sectional survey in China

AIM

Non-steroidal anti-inflammatory drugs (NSAIDs) have been reported to be associated with adverse effects including kidney injury, while relevant studies from developing countries are limited. We aimed to explore the status of NSAIDs use in China, as well as cross-sectional association between NSAIDs intake and presence of chronic kidney disease (CKD).

METHODS

A national representative sample of 47,204 adults in China was used. Prevalence of regular NSAIDs use was reported. Age- and sex- matched controls of NSAIDs users were then selected. The association between NSAIDs use and kidney injury were analyzed using logistic regression.

RESULTS

Altogether 1129 participants reported regular use of NSAIDs, with the adjusted prevalence of 3.6% (95% CI, 3.2%-3.9%). And 76.9% of them (n = 868) had taken phenacetin-containing analgesics, with an adjusted prevalence of 3.2% (95% CI, 2.9%-3.5%). After adjusting for potential confounders, long-term NSAIDs intake (≥ 48 months) was associated with eGFR < 60 mL/min per 1.73 m2, with an OR of 2.36 (95% CI, 1.28-4.37).

CONCLUSION

Regular use of NSAIDs, especially phenacetin-containing drugs, is prevalent in China. And long-term NSAIDs intake (≥ 48 months) was independently associated with reduced renal function.

Genotoxicity of phenacetin in the kidney and liver of Sprague-Dawley gpt delta transgenic rats in 26-week and 52-week repeated-dose studies

Transgenic rat mutation assays can be used to assess genotoxic properties of chemicals in target organs for carcinogenicity. Mutations in transgenes are genetically neutral and accumulate during a treatment period; thus, assays are suitable for assessing the genotoxic risk of chemicals using a repeated-dose treatment paradigm. However, only a limited number of such studies have been conducted. To examine the utility of transgenic rat assays in repeated-dose studies, we fed male and female Sprague-Dawley gpt delta rats with a 0.5% phenacetin-containing diet for 26 and 52 weeks. A long-term feeding of phenacetin is known to induce renal cancer in rats. Phenacetin administration for 52 weeks in males significantly increased gpt (point mutations) mutant frequency (MF) in the kidney, the target organ of carcinogenesis. In the liver, the nontarget organ of carcinogenesis, gpt MFs were significantly elevated in phenacetin treatment groups of both genders during 26- and 52-week treatments. Furthermore, sensitive to P2 interference (Spi(-)deletions) MF increased in the liver of both genders following 52-week treatment. MFs were higher after treatment for 52 weeks than after treatment for 26 weeks. Frequencies of phenacetin-induced mutations were higher in the liver than in the kidney, suggesting that the intensity of genotoxicity does not necessarily correlate with the induction of tumor formation. Results from gpt delta rat assays of repeated-dose treatments are extremely useful to elucidate the relationship between gene mutations and carcinogenesis in the target organ induced by cancer-causing agents.

Sorption behavior of 20 wastewater originated micropollutants in groundwater--column experiments with pharmaceutical residues and industrial agents

Since sorption is an essential process with regard to attenuation of organic pollutants during subsurface flow, information on the sorption properties of each pollutant are essential for assessing their environmental fate and transport behavior. In the present study, the sorption behavior of 20 wastewater originated organic micropollutants was assessed by means of sediment column experiments, since experimentally determined data for these compounds are not or sparsely represented in the literature. Compounds investigated include various psychoactive drugs, phenazone-type pharmaceuticals and β-blockers, as well as phenacetine, N-methylphenacetine, tolyltriazole and para-toluenesulfonamide. While for most of the compounds no or only a low sorption affinity was observed, an elevated tendency to sorb onto aquifer sand was obtained for the β-blockers atenolol, propranolol and metoprolol. A comparison between experimental data and data estimated based on the octanol/water partition coefficient following the QSAR approach demonstrated the limitations of the latter to predict the adsorption behavior in natural systems for the studied compounds.

Caffeine as a promoter of analgesic-associated nephropathy--where is the evidence?

Individual groups of nephrologists - in their responsibility for their patients - initiated a most controversial discussion whether or not caffeine - coformulated to analgesics - might initiate or sustain analgesic overdosing. The original sources (data) of such suspicion have got lost during the debate of the last two decades. Therefore, it seemed to be appropriate to investigate the original data background and the reasons why nephrologists started to suspect caffeine as a stimulant of analgesic overdosing by employing a systematic and exhaustive review of primary nephrological publications. Their selection followed a precise selection plan, including all epidemiological studies on analgesic-associated nephropathy, the original papers of all groups having been involved in those studies, further originals from the mainly involved countries (academically, politically), and any literature thereof cited as a proof. The following results emerged from the investigation: (i) The epidemiological studies warranted no conclusion about a role of caffeine in prompting excessive analgesic use. (ii) The identified groups of nephrologists provided not substantial data to advocate the said suspicion, except for the observation of a preferential choice of phenacetin-containing combinations, especially powder preparations. (iii) Only two cited original data sources revealed drug-seeking behaviour with phenacetin-containing preparations which subsided, after phenacetin was banned from the respective markets. Conclusively, it appears that there is no substantial data to support a pivotal role of caffeine in initiating or sustaining analgesic overdosing. However, there is strong data that phenacetin, by its psychotropic properties, may have caused drug-seeking behaviour and thus led to analgesic overdosing. This conclusion is convincingly supported by thorough pharmacokinetic investigations. Note: All caffeine-related statements within the reviewed literature have been collected in tables (referred to as Table SX) which are provided in full text for check on the following website: http://www.blackwellpublishing.com/products/journals/suppmat/FCP/FCP174/FCP174sm.htm

Mutagenic and analgesic activities of aniline derivatives

Phenacetin (1), acetaminophen (2), acetanilide (3), 4-aminophenol (4), and aniline (5) were tested in S.J.L. Swiss mice for their mutagenic and analgesic activities. The S-analogues of 1 and 2, 4-mercaptoacetanilide (6) and 4-ethylthioacetanilide (7), respectively, were synthesized and tested in the same way to define if both activities could be separated by molecular modification. All the compounds tested exhibited analgesic activity with ED50 values ranging from 12.6 to 158.5 mg/kg. The compounds could be arranged in a decreasing order of analgesic activity as follows: 3 greater than 4 congruent to 5 congruent to 6 greater than 1 congruent to 7 greater than 2. All the compounds, except 6, were positive mutagens in the micronucleus test (statistically significant). The order of relative mutagenic potencies was 1 congruent to 7 greater than 4 greater than 2 congruent to 3 congruent to 5. A narrow dose-response curve relationship was found for 5 and its metabolite 4, the relative mutagenic potencies of which suggest ring hydroxylation as the major pathway of biotoxification. No parallelism was found between analgesic and mutagenic activities, so they could be separated by pharmacomodulation: 6 was more effective as an analgesic in the acetic acid test than 2, and no mutagenic activity was found at the doses assayed.

Microbial models of mammalian metabolism: biotransformations of phenacetin and its O-alkyl homologues with Cunninghamella species

1. The analgesic compound phenacetin and its O-alkyl homologues were metabolized by Cunninghamella elegans to yield the O-dealkylation product paracetamol (acetaminophen), and metabolites resulting from omega-1 hydroxylation and further oxidations. 2. Structural identification was based upon physical, spectral and chromatographic comparisons of isolated metabolites with synthetic standards generated by alkylation of paracetamol with the appropriate alkyl halide, epoxide, or alpha,beta-unsaturated ketone. 3. The rank order of O-dealkylation within the homologous series based upon either substrate disappearance or phenol formation was found to be ethyl greater than isopropyl greater than n-propyl greater than n-butyl greater than methyl.

Inhibition of DNA, RNA and protein synthesis and chromatin alteration by N-hydroxyphenacetin

The effects of N-hydroxyphenacetin on DNA function and structure were investigated to elucidate the involvement of phenacetin in analgesic nephropathy and transitional cell carcinoma. N-Hydroxyphenacetin or a metabolite inhibited synthesis of DNA, RNA and protein; DNA inhibition was greater at higher pH. No single-strand breaks were detectable in DNA after N-hydroxyphenacetin treatment and no appreciable effect on cell viability was observed at concentrations up to 5 mM. N-Hydroxyphenacetin-induced alteration to chromatin structure was detected using nucleoid sedimentation analysis. Direct binding to plasmid DNA was not observed. These observations are consistent with a role for phenacetin metabolites in renal disease.

Experimental induction of renal tumors

Renal tumors have been reported to be induced by natural products, chemical carcinogens, viruses, or radiation. Species or strain specificity and sex also appear to play significant roles in their development. In man, it is also likely that the heredity existence of other diseases, smoking, food habits, and irradiation may be etiological factors. It also appears that hormonal, chemical, and other environmental factors can play a role. Nephrotoxin modifies two-stage chemical carcinogenesis in rat kidney. Some nephrotoxins without carcinogenicity promote the development of renal tumors in rats pretreated with subcarcinogenic doses of chemical carcinogens. The importance of nephrotoxin in development of renal adenocarcinomas needs elucidation. Preneoplastic lesions in the kidneys can be recognized by histochemical methods with specific antibodies. It is hoped that further research will be continued, so that data obtained from experimental work will provide a better understanding of the etiology and induction of renal cancer in man.

Chemically induced renal papillary necrosis and upper urothelial carcinoma. Part 1

In the past, renal papillary necrosis (RPN) has been commonly associated with long-term abusive analgesic intake, but over recent years a wide variety of industrially and therapeutically used chemicals have been shown to induce this lesion experimentally or in man. Destruction of the renal papilla may result in: (1) secondary degenerative cortical changes which precede chronic renal failure or (2) a rapidly metastasizing upper urothelial carcinoma, which has a very poor prognosis. This article will briefly review the published data on the morphology, function, and biochemistry of the normal renal medulla and the pathology associated with RPN, together with the secondary changes which give rise to cortical degeneration or epithelial carcinoma. It will then examine in detail those chemicals which have been reported to cause RPN in an attempt to delineate structure-activity relationships. Finally, the many different theories that have been proposed to explain the pathophysiology of RPN will be examined and an hypothesis will be put forward to explain the primary pathogenesis of the lesion and its secondary consequences.

Chemically induced renal papillary necrosis and upper urothelial carcinoma. Part 2

In the past, renal papillary necrosis (RPN) has been commonly associated with long-term abusive analgesic intake, but over recent years a wide variety of industrially and therapeutically used chemicals have been shown to induce this lesion experimentally or in man. Destruction of the renal papilla may result in: (1) secondary degenerative cortical changes which precede chronic renal failure or (2) a rapidly metastasizing upper urothelial carcinoma, which has a very poor prognosis. This article will briefly review the published data on the morphology, function, and biochemistry of the normal renal medulla and the pathology associated with RPN, together with the secondary changes which give rise to cortical degeneration or epithelial carcinoma. It will then examine in detail those chemicals which have been reported to cause RPN in an attempt to delineate structure-activity relationships. Finally, the many different theories that have been proposed to explain the pathophysiology of RPN will be examined and an hypothesis will be put forward to explain the primary pathogenesis of the lesion and its secondary consequences.

Tissue specific, acute toxic effects of the carcinogen trans-4-dimethylaminostilbene

The acute toxicity of the carcinogen trans-4-dimethylaminostilbene was studied in Wistar rats. The animals die after oral administration of 50 mg/kg (LD50) with a latency period of 11 days. Specific lesions of the stomach epithelium together with acute bone marrow incapacity and toxic effects on peripheral blood cells lead to acute anemia, which is considered to be the cause of death. Histological observations indicate that the stomach lesions develop in three phases. Firstly, necroses appear in the proliferative area predominantly in the antrum. This leads, secondly, to cystic transformation of the antrum, cardia, and Brunner's glands and further to peptic erosions and ulcerations. Thirdly, mitotic activity increases. With lethal doses, cell replacement remains incomplete. There ist a correlation between the proliferation rate of different cell types and their susceptibility; but this cannot entirely account for the tissue-specific, systemic effects of trans-4-dimethylaminostilbene. Metabolic activation is also involved, since enzyme induction with methylcholanthrene inhibits toxicity. The study disclosed a new target tissue which may now be used to investigate the mechanism of action of reactive metabolites of an aromatic amine in acute experiments. The same stomach lesions were also observed with adriamycin. With this compound, however, the intestine is also involved.

Renal effects of antipyretic analgesics

Most antipyretic analgesics can cause acute nephrotoxic effects, including acute tubular necrosis, acute interstitial nephritis, glomerular toxicity, and functional changes, such as "salicyl edema," following large doses of sodium salicylate. Most functional changes are related to acute suppression of prostaglandin synthesis, "the acute prostaglandin-effect," and have been primarily noted with the use of indomethacin. The association between prolonged and excessive consumption of compound analgesics and the development of renal disease and renal failure, characterized by renal papillary necrosis, is now well established. Studies in several countries have shown that the incidence of analgesic nephropathy as an indication for dialysis and transplantation corresponds to the per capita consumption of phenacetin in compound analgesics. Analgesic nephropathy, which is part of a wider clinical syndrome, the analgesic syndrome, is uncommon following the use of single analgesics. Analgesic nephropathy and the analgesic syndrome are discussed in detail, including the development of uroepithelial tumors.

Eighteen month oral study of aspirin, phenacetin and caffeine, in C57Bl/6 mice

Groups of 40 male and 40 female C57BL/6 mice were maintained for 75-80 weeks on meal form diets containing aspirin, phenacetin and caffeine either singly or in combination. The maximum daily doses of phenacetin alone and the APC combination were approximately one-half of their previously determined respective oral LD50's. Mild, nonprogressive histopathologic changes of the urinary tract were noted with these changes first evident in animals given the highest dose of phenacetin. Sulfhemoglobinemia was also induced in all groups of animals given phenacetin alone or in combination indicating that toxic doses were administered oral LD50's. Mild, nonprogressive histopathologic changes of the urinary tract were noted with these changes first evident in animals given the highest dose of phenacetin. Sulfhemoglobinemia was also induced in all groups of animals given phenacetin alone or in combination indicating that toxic doses were administered oral LD50's. Mild, nonprogressive histopathologic changes of the urinary tract were noted with these changes first evident in animals given the highest dose of phenacetin. Sulfhemoglobinemia was also induced in all groups of animals given phenacetin alone or in combination indicating that toxic doses were administered. Under the conditions of this study, evidence of carcinogens was not demonstrated for any of the drugs given alone or in combination.