42045-86-3CCC(=O)N(c1ccccc1)C1CCN(CCc2ccccc2)CC1CMLQRZXNZHAOCHQ-UHFFFAOYSA-N3-methylfentanyl is the monocarboxylic acid amide resulting from the formal condensation of the aryl amino group of 3-methyl-N-phenyl-1-(2-phenylethyl)piperidin-4-amine with propanoic acid. It has a role as an opioid analgesic, a sedative and a mu-opioid receptor agonist. It is an anilide, a member of piperidines, a monocarboxylic acid amide and a tertiary amino compound.
DEA NFLIS-Drug Category -> Fentanyl and Fentanyl-related
DEA Schedule I Controlled Substance -> Opiates
안전 정보는 참고용이며, 공급업체의 물질안전보건자료(SDS), 관련 법규 및 전문가 평가를 대체하지 않습니다.
Schedule I shall consist of the drugs and other substances, by whatever official name, common or usual name, chemical name, or brand name designated, listed in this section. Each drug or substance has been assigned the DEA Controlled Substances Code Number set forth opposite it. ... Opiates. Unless specifically excepted or unless listed in another schedule, any of the following opiates, including their isomers, esters, ethers, salts, and salts of isomers, esters and ethers, whenever the existence of such isomers, esters, ethers and salts is possible within the specific chemical designation (for purposes of paragraph (b)(34) only, the term isomer includes the optical and geometric isomers). 3-Methylfentanyl (N-[3-methyl-1-(2-phenylethyl)-4-piperidyl]-N-phenylpropanamide) (DEA Code Number: 9813) is included on this list.
Fentanyl is a synthetic opioid analgesic historically used as a pain reliever and an anesthetic. Recent concerns have arisen around the illicit use of fentanyl and its analogs in a number of European countries, linked to their high potency and associated risk of fatal overdose. Evidence has been emerging from Estonia for over a decade of entrenched patterns of fentanyl use, including injection of the drug and hundreds of overdose deaths. More recently, reports indicate that both fentanyl and 3-methylfentanyl (TMF) have been marketed as a replacement for heroin in European countries (e.g. Bulgaria, Slovakia) affected by heroin shortages. In addition, Germany, Finland and the United Kingdom, reported new outbreaks of fentanyl-related deaths. This combination of increasing mortality data alongside law enforcement intelligence suggesting both diversion and illicit production of fentanyls, prompted wider investigation using a targeted multi-source data collection exercise and analysis. This identified that in the European context, fentanyls are 'low use but high risk/harm' substances. Evidence shows that Estonia stands out as having an endemic problem, while the use of fentanyls in other European countries appears to be geographically localized. Developments in illicit supply of fentanyls reflect the complexity of Europe's contemporary drug market: manifesting illicit production and use, the diversion and misuse of medicines, and the online sale of non-controlled new psychoactive substances. Likewise effective and integrated responses will need to address fentanyl production, diversion as well as ensuring the availability of harm reduction measures to users.
3-Methylfentanyl exhibits similar pharmacodynamic effects to fentanyl but has been proven to be significantly stronger in these effects due to increased binding affinity to the opioid receptor. Fentanyl, administered alone, has a strong affinity for opioid receptors. 3-methylfentanyl has the potential to be extremely hazardous when used without the prescription and supervision of a medical professional. Ingestion of this drug has resulted in numerous deaths among individuals using the drug recreationally.
Opiate receptors are coupled with G-protein receptors and function as both positive and negative regulators of synaptic transmission via G-proteins that activate effector proteins. Binding of the opiate stimulates the exchange of GTP for GDP on the G-protein complex. As the effector system is adenylate cyclase and cAMP located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine and noradrenaline is inhibited. Opioids also inhibit the release of vasopressin, somatostatin, insulin and glucagon. Fentanyl's analgesic activity is, most likely, due to its conversion to morphine. Opioids close N-type voltage-operated calcium channels (OP2-receptor agonist) and open calcium-dependent inwardly rectifying potassium channels (OP3 and OP1 receptor agonist). This results in hyperpolarization and reduced neuronal excitability.
The present study demonstrates that pretreatment of rat brain membranes with (+)-cis-3-methylfentanyl [(+)-cis-MF], followed by extensive washing of the membranes, produces a wash-resistant decrease in the binding of (3)-H-[D-ala2,D-leu5]enkephalin to the d binding site of the opioid receptor complex (delta cx binding site). Intravenous administration of (+)-cis-MF (50 micrograms/kg) to rats produced a pronounced catalepsy and also produced a wash-resistant masking of delta cx and mu binding sites in membranes prepared 120 min post-injection. Administration of 1 mg/kg i.v. of the opioid antagonist, 6-desoxy-6 beta-fluoronaltrexone (cycloFOXY), 100 min after the injection of (+)-cis-MF (20 min prior to the preparation of membranes) completely reversed the catatonia and restored masked delta cx binding sites to control levels. This was not observed with (+)-cycloFOXY. The implications of these and other findings for the mechanism of action of (+)-cis-MF and models of the opioid receptors are discussed. /(+)-cis-3-Methylfentanyl/
현재 필터 조건에 해당하는 반응 기록이 없습니다.
불러오는 중…
42045-86-3DTXSID30962228CHEMBL4748291CHEBI:61092SRP: Expired or waste pharmaceuticals shall carefully take into consideration applicable DEA, EPA, and FDA regulations. It is not appropriate to dispose by flushing the pharmaceutical down the toilet or discarding to trash. If possible return the pharmaceutical to the manufacturer for proper disposal being careful to properly label and securely package the material. Alternatively, the waste pharmaceutical shall be labeled, securely packaged and transported by a state licensed medical waste contractor to dispose by burial in a licensed hazardous or toxic waste landfill or incinerator.
Three fatal poisoning cases due to 3-methylfentanyl are described. In each case, the death was accidental and occurred after injection of the opioid combined with amphetamine, heroin, or other drugs. The victims' ages, ranging from 30 to 41 years, were higher than those typically found in heroin poisonings in Finland. The blood concentrations of cis-3-methylfentanyl, measured here for the first time by a specific tandem mass spectrometric method, ranged from 0.3 to 0.9 ug/L (mean 0.5 ug/L). These values are significantly lower than the levels reported for alpha-methylfentanyl and fentanyl in fatal poisonings. Repeated seizures of fentanyl and its analogs have been reported in Europe close to the Russian border.
An exceptional epidemic of poisonings due to the highly potent opioid designer drug 3-methylfentanyl (TMF) was revealed among Estonian drug users in 2005-2006 by post-mortem forensic toxicology. Quantitative analysis of cis-TMF, trans-TMF, and fentanyl was performed by liquid chromatography-tandem mass spectrometry. Comprehensive toxicological analysis was performed using a multi-technique approach. The number of TMF-related fatal accidental poisonings identified was 46 and 71 for 2005 and 2006, respectively. The proportion of male victims was 91.5% and the mean age of all victims was 26 years at death. TMF was used predominantly by intravenous injection. There was no significant difference in the blood concentrations of cis-TMF and trans-TMF between pure TMF poisonings and mixed TMF poisonings. The mean combined concentration of TMF stereoisomers among pure TMF cases (1.9 ug/L) was more than ten times lower than the mean fentanyl concentration in fentanyl-related fatalities. Concomitant use of other drugs involved alcohol, amphetamines, benzodiazepines, and cannabis, but very rarely other opioids.
TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 65,000(SRC), determined from a structure estimation method(2), indicates that 3-methylfentanyl is expected to be immobile in soil(SRC). The estimated pKa of 3-methylfentanyl is 9.08(3), indicating that this compound will exist almost entirely in the cation form in the environment and cations generally adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(4). Volatilization of the cation from moist soil is not expected because cations do not volatilize(SRC). 3-Methylfentanyl is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.9X10-9 mm Hg at 25 °C(SRC), determined from a fragment constant method(2). Biodegradation data in soil were not available(SRC, 2017).
AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 65,000(SRC), determined from a structure estimation method(2), indicates that 3-methylfentanyl is expected to adsorb to suspended solids and sediment(SRC). An estimated pKa of 9.08(3) indicates 3-methylfentanyl will exist almost entirely in the cation form at pH values of 5 to 9 and, therefore, volatilization from water surfaces is not expected to be an important fate process(SRC). 3-Methylfentanyl is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(4). According to a classification scheme(5), an estimated BCF of 320(SRC), from an estimated log Kow of 4.31(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is high. Biodegradation data in water were not available(SRC, 2017).
ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 3-methylfentanyl, which has an estimated vapor pressure of 2.9X10-9 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely in the particulate phase. Particulate-phase 3-methylfentanyl may be removed from the air by wet and dry deposition(SRC). 3-Methylfentanyl contains chromophores that absorb at wavelengths >290 nm(3) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).
IDENTIFICATION AND USE: 3-Methylfentanil (TMF) is a Schedule I controlled substance. The opioid TMF is a designer drug of the fentanyl type with high potency and abuse potential. HUMAN STUDIES: An exceptional epidemic of poisonings due to TMF was revealed among Estonian drug users in 2005-2006 by post-mortem forensic toxicology. TMF was used predominantly by intravenous injection. Concomitant use of other drugs involved alcohol, amphetamines, benzodiazepines, and cannabis, but very rarely other opioids. More recently, reports indicate that both fentanyl and TMF have been marketed as a replacement for heroin in European countries. ANIMAL STUDIES: Intravenous administration of (+)-cis-TMF (50 ug/kg) to rats produced a pronounced catalepsy.
Using a structure estimation method based on molecular connectivity indices(1), the Koc of 3-methylfentanyl can be estimated to be 65,000(SRC). According to a classification scheme(2), this estimated Koc value suggests that 3-methylfentanyl is expected to be immobile in soil. The estimated pKa of 3-methylfentanyl is 9.08(3), indicating that this compound will exist almost entirely in cation form in the environment and cations generally adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(4).
/CASE REPORTS/ Three fatal poisoning cases due to 3-methylfentanyl are described. In each case, the death was accidental and occurred after injection of the opioid combined with amphetamine, heroin, or other drugs. The victims' ages, ranging from 30 to 41 years, were higher than those typically found in heroin poisonings in Finland. The blood concentrations of cis-3-methylfentanyl, measured here for the first time by a specific tandem mass spectrometric method, ranged from 0.3 to 0.9 ug/L (mean 0.5 ug/L). These values are significantly lower than the levels reported for alpha-methylfentanyl and fentanyl in fatal poisonings. Repeated seizures of fentanyl and its analogs have been reported in Europe close to the Russian border.
/CASE REPORTS/ An exceptional epidemic of poisonings due to the highly potent opioid designer drug 3-methylfentanyl (TMF) was revealed among Estonian drug users in 2005-2006 by post-mortem forensic toxicology. Quantitative analysis of cis-TMF, trans-TMF, and fentanyl was performed by liquid chromatography-tandem mass spectrometry. Comprehensive toxicological analysis was performed using a multi-technique approach. The number of TMF-related fatal accidental poisonings identified was 46 and 71 for 2005 and 2006, respectively. The proportion of male victims was 91.5% and the mean age of all victims was 26 years at death. TMF was used predominantly by intravenous injection. There was no significant difference in the blood concentrations of cis-TMF and trans-TMF between pure TMF poisonings and mixed TMF poisonings. The mean combined concentration of TMF stereoisomers among pure TMF cases (1.9 ug/L) was more than ten times lower than the mean fentanyl concentration in fentanyl-related fatalities. Concomitant use of other drugs involved alcohol, amphetamines, benzodiazepines, and cannabis, but very rarely other opioids.
/OTHER TOXICITY INFORMATION/ Fentanyl is a synthetic opioid analgesic historically used as a pain reliever and an anesthetic. Recent concerns have arisen around the illicit use of fentanyl and its analogs in a number of European countries, linked to their high potency and associated risk of fatal overdose. Evidence has been emerging from Estonia for over a decade of entrenched patterns of fentanyl use, including injection of the drug and hundreds of overdose deaths. More recently, reports indicate that both fentanyl and 3-methylfentanyl (TMF) have been marketed as a replacement for heroin in European countries (e.g. Bulgaria, Slovakia) affected by heroin shortages. In addition, Germany, Finland and the United Kingdom, reported new outbreaks of fentanyl-related deaths. This combination of increasing mortality data alongside law enforcement intelligence suggesting both diversion and illicit production of fentanyls, prompted wider investigation using a targeted multi-source data collection exercise and analysis. This identified that in the European context, fentanyls are 'low use but high risk/harm' substances. Evidence shows that Estonia stands out as having an endemic problem, while the use of fentanyls in other European countries appears to be geographically localized. Developments in illicit supply of fentanyls reflect the complexity of Europe's contemporary drug market: manifesting illicit production and use, the diversion and misuse of medicines, and the online sale of non-controlled new psychoactive substances. Likewise effective and integrated responses will need to address fentanyl production, diversion as well as ensuring the availability of harm reduction measures to users.
3-Methylfentanyl's production and use as an illegal drug(1) will result in its release to the environment through various waste streams(SRC). It is classified as a Schedule I illegal narcotic(1). There are no registered uses for 3-methylfentanyl, an opiate(2).
An estimated BCF of 320 was calculated in fish for 3-methylfentanyl(SRC), using an estimated log Kow of 4.31(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is high.
An estimated pKa of 9.08(1) indicates 3-methylfentanyl will exist almost entirely in the cation form at pH values of 5 to 9 and, therefore, volatilization from water and moist soil surfaces is not expected to be an important fate process(SRC). 3-Methylfentanyl is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.9X10-9 mm Hg(SRC), determined from a fragment constant method(2).
3-Methylfentanyl is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(1). 3-Methylfentanyl contains chromophores that absorb at wavelengths >290 nm(1) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).
Occupational exposure and general population exposure should be low or non-existent since 3-methylfentanyl is no longer produced or used legally in the US. Exposure to 3-methylfentanyl is limited to those producing and using it as an illicit drug. (SRC)
3-Methylfentanyl's production and use as an illegal drug will result in its release to the environment through various waste streams. It is classified as a Schedule I illegal narcotic. There are no registered uses for 3-methylfentanyl, an opiate. If released to air, an estimated vapor pressure of 2.9X10-9 mm Hg at 25 °C indicates 3-methylfentanyl will exist solely in the particulate phase in the atmosphere. Particulate-phase 3-methylfentanyl will be removed from the atmosphere by wet and dry deposition. 3-Methylfentanyl contains chromophores that absorb at wavelengths >290 nm and, therefore, may be susceptible to direct photolysis by sunlight. If released to soil, 3-methylfentanyl is expected to have no mobility based upon an estimated Koc of 65,000. The estimated pKa of 3-methylfentanyl is 9.08, indicating that this compound will exist almost entirely in the cation form in the environment and cations generally adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts. Volatilization from moist soil is not expected because the compound exists as a cation and cations do not volatilize. 3-Methylfentanyl is not expected to volatilize from dry soil surfaces based upon its estimated vapor pressure. Biodegradation data in soil or water were not available. If released into water, 3-methylfentanyl is expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated pKa. An estimated BCF of 320 suggests the potential for bioconcentration in aquatic organisms is high. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions (pH 5 to 9). Occupational exposure and general population exposure should be low or non-existent since 3-methylfentanyl is no longer produced or used legally in the US. Exposure to 3-methylfentanyl is limited to those producing and using it as an illicit drug. (SRC)
/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/
/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . /Poisons A and B/
/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W TKO /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/
Emergency and supportive measures. 1. Maintain an open airway and assist ventilation if necessary. Administer supplemental oxygen. Treat coma, seizures, hypotension, and noncardiogenic pulmonary edema if they occur. /Opiates and opioids/
For more Antidote and Emergency Treatment (Complete) data for 3-Methylfentanil (7 total), please visit the HSDB record page.
Schedule I shall consist of the drugs and other substances, by whatever official name, common or usual name, chemical name, or brand name designated, listed in this section. Each drug or substance has been assigned the DEA Controlled Substances Code Number set forth opposite it. ... Opiates. Unless specifically excepted or unless listed in another schedule, any of the following opiates, including their isomers, esters, ethers, salts, and salts of isomers, esters and ethers, whenever the existence of such isomers, esters, ethers and salts is possible within the specific chemical designation (for purposes of paragraph (b)(34) only, the term isomer includes the optical and geometric isomers). 3-Methylfentanyl (N-[3-methyl-1-(2-phenylethyl)-4-piperidyl]-N-phenylpropanamide) (DEA Code Number: 9813) is included on this list.
The opioid 3-methylfentanyl, a designer drug of the fentanyl type, was scheduled by the Controlled Substance Act due to its high potency and abuse potential. To overcome this regulation, isofentanyl, another designer fentanyl, was synthesized in a clandestine laboratory and seized by the German police. The aims of the presented study were to identify the phase I and phase II metabolites of 3-methylfentanyl and isofentanyl in rat urine, to identify the cytochrome P450 (CYP) isoenzymes involved in their initial metabolic steps, and, finally, to test their detectability in urine. Using liquid chromatography (LC)-linear ion trap-mass spectrometry (MS(n)), nine phase I and five phase II metabolites of 3-methylfentanyl and 11 phase I and four phase II metabolites of isofentanyl could be identified. The following metabolic steps could be postulated for both drugs: N-dealkylation followed by hydroxylation of the alkyl and aryl moiety, hydroxylation of the propanamide side chain followed by oxidation to the corresponding carboxylic acid, and, finally, hydroxylation of the benzyl moiety followed by methylation. In addition, N-oxidation of isofentanyl could also be observed. All hydroxy metabolites were partly excreted as glucuronides. Using recombinant human isoenzymes, CYP2C19, CYP2D6, CYP3A4, and CYP3A5 were found to be involved in the initial metabolic steps. Our LC-MS(n) screening approach allowed the detection of 0.01 mg/L of 3-methylfentanyl and isofentanyl in spiked urine. However, in urine of rats after the administration of suspected recreational doses, the parent drugs could not be detected, but their common nor metabolite, which should therefore be the target for urine screening.
3-Methylfentanyl (DEA Code Number: 9813) is a Schedule I controlled substance.
Schedule I Controlled Substance: (A) The drug or other substance has a high potential for abuse; (B) The drug or other substance has no currently accepted medical use in treatment in the United States; and (C) There is a lack of accepted safety for use of the drug or other substance under medical supervision.
Analgesics
Fentanyl is a synthetic opioid analgesic historically used as a pain reliever and an anaesthetic. Recent concerns have arisen around the illicit use of fentanyl and its analogues in a number of European countries, linked to their high potency and associated risk of fatal overdose. Evidence has been emerging from Estonia for over a decade of entrenched patterns of fentanyl use, including injection of the drug and hundreds of overdose deaths. More recently, reports indicate that both fentanyl and 3-methylfentanyl (TMF) have been marketed as a replacement for heroin in European countries (e.g. Bulgaria, Slovakia) affected by heroin shortages. In addition, Germany, Finland and the United Kingdom, reported new outbreaks of fentanyl-related deaths. This combination of increasing mortality data alongside law enforcement intelligence suggesting both diversion and illicit production of fentanyls, prompted wider investigation using a targeted multi-source data collection exercise and analysis. This identified that in the European context, fentanyls are 'low use but high risk/harm' substances. Evidence shows that Estonia stands out as having an endemic problem, while the use of fentanyls in other European countries appears to be geographically localised. Developments in illicit supply of fentanyls reflect the complexity of Europe's contemporary drug market: manifesting illicit production and use, the diversion and misuse of medicines, and the online sale of non-controlled new psychoactive substances. Likewise effective and integrated responses will need to address fentanyl production, diversion as well as ensuring the availability of harm reduction measures to users.
용도A potent analgesic drug. Controlled Substance
정의ChEBI: The monocarboxylic acid amide resulting from the formal condensation of the aryl amino group of 3-methyl-N-phenyl-1-(2-phenylethyl)piperidin-4-amine with propanoic acid.
/OTHER TOXICITY INFORMATION/ 3-Methylfentanyl ("China White") is a "designer" opiate that has caused more than 100 overdose deaths in California since 1979, but that has not been associated previously with deaths east of the Rocky Mountains. During 1988, 3-methylfentanyl was identified in 16 fatal overdose cases in Allegheny County, Pennsylvania, contributing to a fourfold rise in overdose mortality during October of that year. Morphine was detected in the blood of five persons (31%) and cocaine in the blood of three persons (19%) dying of 3-methylfentanyl overdoses; these were demographically similar to 99 other fatal overdose cases investigated by the county coroner from 1986 through 1988. This documents the contribution of 3-methylfentanyl to overdose mortality in an eastern city and the use of 3-methylfentanyl with other illegal drugs. Drug abusers in the northeastern United States should be considered at risk for more "designer drug" overdose outbreaks in the future.
/OTHER TOXICITY INFORMATION/ The purpose of this study was to isolate significant clinical or demographic findings concerning overdose patients treated during a China White (3-methyl fentanyl) epidemic and compare them with data for all unintentional narcotic overdose patients during a 24-month period. We reviewed charts from 85,246 patient visits to our emergency department during the 24-month period of January 1987 through December 1988 to study this narcotic epidemic. Data from the Allegheny County Coroner's Office pertaining to unintentional drug overdose deaths that occurred during this same period also were reviewed. The first outbreak of narcotic overdoses in the eastern United States involving China White occurred in Allegheny County, Pennsylvania, in 1988. Patients were included if they met the criteria of a suspected unintentional narcotic overdose, but excluded if they were not given naloxone. Emergency physicians became suspicious of China White use after an unusual increase in narcotic overdoses presenting to the ED coupled with "routine drug of abuse" screens negative for opiates despite dramatic patient responses to naloxone. In most of the cases in which specific testing was done, there were positive indicators of fentanyl derivatives. Investigations found China White present in street drugs and paraphernalia. A cluster was defined as a time period with a statistically significant increase in overdoses over the expected number for an interval of equal length. Although there were no significant clinical differences in case presentation during the 24-month period, there was a statistically significant 13-fold increase in overdoses during the September through November 1988 cluster (mean, 13 vs 0.95 per month, P less than 0.001 by Wilcoxon rank-sum test). A dramatic increase in unintentional drug overdose deaths occurred in the county during this cluster. A total of 18 fentanyl-positive unintentional drug overdose deaths, predominantly male (89%) and black (56%), with an age range of 19 to 44 years (mean, 34.9 years), were reported by the county coroner (13 during the cluster). Narcotic overdoses and unintentional drug overdose deaths declined sharply with confiscation of a clandestine China White laboratory. China White was responsible for a dramatic rise in unintentional drug overdose deaths in Allegheny County in 1988. There were no significant clinical differences between China White overdose survivors and other unintentional narcotic overdose victims. Overdoses responsive to naloxone with inconsistent routine toxicologic screens may be due to a fentanyl analogue.