Philippines - English - FDA (Food And Drug Administration)

pfizer, inc. - demerol - solution for injection (i.m./i.v./s.c.) - 50 mg/ml (100 mg/2ml)

Philippines - English - FDA (Food And Drug Administration)

pfizer, inc. - demerol - solution for injection (im/sc) - 50mg/ml

United States - English - NLM (National Library of Medicine)

validus pharmaceuticals llc - meperidine hydrochloride (unii: n8e7f7q170) (meperidine - unii:9e338qe28f) - meperidine hydrochloride 50 mg - demerol tablets and oral solution are indicated for the management of acute pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. limitations of use because of the risks of addiction, abuse, and misuse with opioids, which can occur at any dosage or duration [see warnings and precautions ( 5.2 ) ] , reserve demerol tablets or oral solution for use in patients for whom alternative treatment options (e.g., non-opioid analgesics or opioid combination products): - have not been tolerated, or are not expected to be tolerated, - have not provided adequate analgesia, or are not expected to provide adequate analgesia. demerol tablets and oral solution should not be used for an extended period of time unless the pain remains severe enough to require an opioid analgesic and for which alternative treatment options continue to be inadequate. demerol tablets or oral solution should not be used for the treatment of chronic pain. use of demerol tablet or oral solution for an extended period of time may increase the risk of toxicity (e.g., seizures) from the accumulation of the meperidine metabolite, normeperidine. demerol tablets and oral solution are contraindicated in patients with: - significant respiratory depression [see warnings and precautions ( 5.4 )] - acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment [see warnings and precautions ( 5.9 )] - concomitant use of monoamine oxidase inhibitors (maois) or within 14 days of having taken an maoi [see drug interactions ( 7 )] - known or suspected gastrointestinal obstruction, including paralytic ileus [see warnings and precautions ( 5.14 )] - hypersensitivity to meperidine or to any of other ingredients of the product (e.g., anaphylaxis) [see adverse reactions ( 6 )] risk summary use of opioid analgesics for an extended period of time during pregnancy may cause neonatal opioid withdrawal syndrome [see warnings and precautions ( 5.5 )] . available data with demerol tablets or oral solution are insufficient to inform a drug-associated risk for major birth defects and miscarriage or adverse maternal outcomes. formal animal reproduction studies have not been conducted with meperidine. neural tube defects (exencephaly and cranioschisis) have been reported in hamsters administered a single bolus dose of meperidine during a critical period of organogenesis at 0.85 and 1.5 times the total human daily dose of 1200 mg [see data ] .    the background risk of major birth defects and miscarriage for the indicated population is unknown. all pregnancies have a background risk of birth defects, loss or other adverse outcomes. in the u.s. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. clinical considerations fetal/neonatal adverse reactions use of opioid analgesics for an extended period of time during pregnancy for medical or nonmedical purposes can result in physical dependence in the neonate and neonatal opioid withdrawal syndrome shortly after birth. neonatal opioid withdrawal syndrome presents as irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea, and failure to gain weight. the onset, duration, and severity of neonatal opioid withdrawal syndrome vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination of the drug by the newborn. observe newborns for symptoms of neonatal opioid withdrawal syndrome and manage accordingly [see warnings and precautions ( 5.5 )] . labor or delivery opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in neonates. resuscitation may be required [ see overdose ( 10 ) ].   an opioid antagonist, such as naloxone, must be available for reversal of opioid-induced respiratory depression in the neonate. demerol tablets and oral solution are not recommended for use in pregnant women during or immediately prior to labor, when other analgesic techniques are more appropriate. opioid analgesics, including demerol tablets or oral solution, can prolong labor through actions which temporarily reduce the strength, duration, and frequency of uterine contractions. however, this effect is not consistent and may be offset by an increased rate of cervical dilation, which tends to shorten labor. monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression.    data animal data formal reproductive and developmental toxicology studies for meperidine have not been completed. in a published study, neural tube defects (exencephaly and cranioschisis) were noted following subcutaneous administration of meperidine hydrochloride (127 and 218 mg/kg, respectively) on gestation day 8 to pregnant hamsters (0.85 and 1.5 times the total daily dose of 1200 mg/day based on body surface area). the findings cannot be clearly attributed to maternal toxicity. risk summary meperidine appears in the milk of nursing mothers receiving the drug. the developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for demerol tablets or oral solution and any potential adverse effects on the breastfed infant from demerol tablets or oral solution or from the underlying maternal condition. clinical considerations monitor infants exposed to demerol tablets or oral solution through breast milk for excess sedation and respiratory depression. withdrawal symptoms can occur in breast-fed infants when maternal administration of an opioid analgesic is stopped, or when breast-feeding is stopped. infertility use of opioids for an extended period of time may cause reduced fertility in females and males of reproductive potential. it is not known whether these effects on fertility are reversible [see adverse reactions ( 6 ) , clinical pharmacology ( 12.2 )], nonclinical   toxicology ( 13.1 ) ] . the safety and effectiveness of meperidine in pediatric patients has not been established. literature reports indicate that meperidine has a slower elimination rate in neonates and young infants compared to older children and adults. neonates and young infants may also be more susceptible to the effects, especially the respiratory depressant effects. if meperidine use is contemplated in neonates or young infants, any potential benefits of the drug need to be weighed against the relative risk of the patient. clinical studies of demerol tablets and oral solution during product development did not include sufficient numbers of subjects aged 65 and over to evaluate age-related differences in safety or efficacy. literature reports indicate that geriatric patients have a slower elimination rate compared to young patients and they may be more susceptible to the effects of meperidine. reducing the total daily dose of meperidine is recommended in elderly patients, and the potential benefits of the drug should be weighed against the relative risk to a geriatric patient. respiratory depression is the chief risk for elderly patients treated with opioids, and has occurred after large initial doses were administered to patients who were not opioid-tolerant or when opioids were co-administered with other agents that depress respiration. titrate the dosage of demerol slowly in geriatric patients and frequent reevaluate the patient for signs of central nervous system and respiratory depression [see warnings and precautions ( 5.11 )] . meperidine is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to regularly evaluate renal function. accumulation of meperidine and/or its active metabolite, normeperidine, can occur in patients with hepatic impairment. elevated serum levels have been reported to cause central nervous system excitatory effects. meperidine should therefore be used with caution in patients with hepatic impairment. titrate the dosage of demerol tablets or oral solution slowly in patients with hepatic impairment and regularly evaluate for signs of central nervous system and respiratory depression. accumulation of meperidine and/or its active metabolite, normeperidine, can also occur in patients with renal impairment. meperidine should therefore be used with caution in patients with renal impairment. titrate the dosage of demerol tablets or oral solution slowly in patients with renal impairment and regularly evaluate for signs of central nervous system and respiratory depression. demerol tablets and oral solution contain meperidine, a schedule ii controlled substance. demerol tablets and oral solution contain meperidine, a substance with a high potential for misuse and abuse, which can lead to the development of substance use disorder, including addiction [see warnings and precautio ns ( 5.2 )] . misuse is the intentional use, for therapeutic purposes, of a drug by an individual in a way other than prescribed by a health care provider or for whom it was not prescribed. abuse is the intentional, non-therapeutic use of a drug, even once, for its desirable psychological or physiological effects. drug addiction is a cluster of behavioral, cognitive, and physiological phenomena that may lead to central nervous system and respiratory depression, hypotension, seizures, and death. the risk is increased with concurrent abuse of demerol tablets and oral solution with alcohol and/or other cns depressants. abuse of an addiction to opioids in some individuals may not be accompanied by concurrent tolerance and symptoms of physical dependence. in addition, abuse of opioids can occur in the absence of addiction. all patients treated with opioids require careful and frequent re-evaluation for signs of misuse, abuse, and addiction, because use of opioid analgesic products carries the risk of addiction even under appropriate medical use. patients at high risk of demerol tablets and oral solution abuse include those with a history of prolonged use of products containing meperidine, those with a history of drug or alcohol abuse, or those who use demerol tablets and oral solution in combination with other abused drugs. “drug-seeking” behavior is very common in persons with substance use disorders. drug-seeking tactics include emergency calls or visits near the end of office hours, refusal to undergo appropriate examination, testing, or referral, repeated “loss” of prescriptions, tampering with prescriptions, and reluctance to provide prior medical records or contact information for other treating healthcare provider(s). “doctor shopping” (visiting multiple prescribers to obtain additional prescriptions) is common among people who abuse drugs and people with substance use disorder. preoccupation with achieving adequate pain relief can be appropriate behavior in a patient with inadequate pain control. demerol tablets and oral solution, like other opioids, can be diverted for non-medical use into illicit channels of distribution. careful record-keeping of prescribing information, including quantity, frequency, and renewal requests, as required by state and federal law, is strongly advised. proper assessment of the patient, proper prescribing practices, periodic re-evaluation of therapy, and proper dispensing and storage are appropriate measures that help to limit abuse of opioid drugs. risks specific to abuse of demerol   tablets and oral solution abuse of demerol tablets and oral solution poses a risk of overdose and death. the risk in increased with concurrent use of demerol tablets and oral solution with alcohol and/or other cns depressants. demerol tablets and oral solution is approved for oral use only.  demerol tablets have been reported as being abused by crushing, chewing, snorting, or injecting the dissolved product.  inappropriate intravenous, intramuscular, or subcutaneous use of demerol tablets or oral solution can result in death, local tissue necrosis, infection, pulmonary granulomas, increased risk of endocarditis, and valvular heart injury, and embolism. parenteral drug abuse is commonly associated with transmission of infectious diseases such as hepatitis and hiv. both tolerance and physical dependence can develop during use of opioid therapy. tolerance is  a physiological state characterized by a reduced response to a drug after repeated administration (i.e., a higher dose of a drug is required to product the same effect that was once obtained at a lower dose). physical dependence is a state that develops as a result of a physiological adaption in response to repeated drug use, manifested by withdrawal signs and symptoms after abrupt discontinuation or a significant dose reduction of a drug.  withdrawal may be precipitated through the administration of drugs with opioid antagonist activity (e.g., naloxone), mixed agonist/antagonist analgesics (e.g., pentazocine, butorphanol, nalbuphine), or partial agonists (e.g., buprenorphine). physical dependence may not occur to a clinically significant degree until after several days to weeks of continued use. do not abruptly discontinue demerol tablets and oral solution in a patient physically dependent on opioids. rapid tapering of demerol tablets and oral solution in a patient physically dependent on opioids may lead to serious withdrawal symptoms, uncontrolled pain, and suicide. rapid discontinuation has also been associated with attempts to find other sources of opioid analgesics, which may be confused with drug-seeking for abuse. when discontinuing demerol tablets and oral solution, gradually taper the dosage using a patient-specific plan that considers the following: the dose of demerol tablets and oral solution the patient has been taking, the duration of treatment, and the physical and psychological attributes of the patient. to improve the likelihood of a successful taper and minimize withdrawal symptoms, it is important that the opioid tapering schedule is agreed upon by the patient. in patients taking opioids for an extended period of time at high doses, ensure that a multimodal approach to pain management, including mental health support (if needed), is in place prior to initiating an opioid analgesic taper [see dosage and administration ( 2.6 ), warnings and precautions ( 5.17 )] . infants born to mothers physically dependent on opioids will also be physically dependent and may exhibit respiratory difficulties and withdrawal signs [see use in specific populations ( 8.1 )] .

United States - English - NLM (National Library of Medicine)

hospira, inc. - meperidine hydrochloride (unii: n8e7f7q170) (meperidine - unii:9e338qe28f) - meperidine hydrochloride 25 mg in 1 ml - demerol injection is indicated for preoperative medication, support of anesthesia, and obstetrical analgesia. demerol injection is indicated for the management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. limitations of use: because of the risks of addiction, abuse, and misuse with opioids, which can occur at any dosage or duration [see warnings and precautions (5.1)] , reserve demerol injection for use in patients for whom alternative treatment options (e.g., non-opioid analgesics or opioid combination products): demerol injection should not be used for an extended period of time unless the ‎pain remains severe enough to require an opioid analgesic and for which ‎alternative treatment options continue to be inadequate.‎ use of demerol injection for an extended period of time may increase the risk of toxicity (e.g., seizures) from the accumulation of the meperidine metabolite, normeperidine. demerol injection is contraindicated in patients with: risk summary use of opioid analgesics for an extended period of time during pregnancy may cause neonatal opioid withdrawal syndrome [see warnings and precautions (5.4)] . available data with demerol injection are insufficient to inform a drug-associated risk for major birth defects and miscarriage or adverse maternal outcomes. there are adverse outcomes reported with fetal exposure to opioid analgesics (see clinical ‎‎considerations) . formal animal reproduction studies have not been conducted with meperidine. neural tube defects (exencephaly and cranioschisis) have been reported in hamsters administered a single bolus dose of meperidine during a critical period of organogenesis at 0.85 and 1.5 times the total human daily dose of 1200 mg. [see data ] the background risk of major birth defects and miscarriage for the indicated population is unknown. all ‎‎pregnancies have a background risk of birth defect, loss, or other adverse outcomes. in the u.s. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. clinical considerations fetal/neonatal adverse reactions use of opioid analgesics for an extended period of time during pregnancy for medical or nonmedical purposes can result in physical dependence in the neonate and neonatal opioid withdrawal syndrome shortly after birth. neonatal opioid withdrawal syndrome presents as irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea, and failure to gain weight. the onset, duration, and severity of neonatal opioid withdrawal syndrome vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination of the drug by the newborn. observe newborns for symptoms of neonatal opioid withdrawal syndrome and manage accordingly [see warnings and precautions (5.4)] . labor or delivery opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in neonates. an opioid antagonist, such as naloxone, must be available for reversal of opioid-induced respiratory depression in the neonate. demerol injection is not recommended for use in pregnant women during or immediately prior to labor, when other analgesic techniques are more appropriate. opioid analgesics, including demerol injection, can prolong labor through actions which temporarily reduce the strength, duration, and frequency of uterine contractions. however, this effect is not consistent and may be offset by an increased rate of cervical dilation, which tends to shorten labor. monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression. data animal data formal reproductive and developmental toxicology studies for meperidine have not been completed. in a published study, neural tube defects (exencephaly and cranioschisis) were noted following subcutaneous administration of meperidine hydrochloride (127 and 218 mg/kg, respectively) on gestation day 8 to pregnant hamsters (0.85 and 1.5 times the total daily dose of 1200 mg/day based on body surface area). the findings cannot be clearly attributed to maternal toxicity. risk summary meperidine appears in the milk of nursing mothers receiving the drug. the developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for demerol injection and any potential adverse effects on the breastfed infant from demerol injection or from the underlying maternal condition. clinical considerations monitor infants exposed to demerol injection through breast milk for excess sedation and respiratory depression. withdrawal symptoms can occur in breastfed infants when maternal administration of an opioid analgesic is stopped, or when breast-feeding is stopped. infertility use of opioids for an extended period of time may cause reduced fertility in females and males of reproductive potential. it is not known whether these effects on fertility are reversible [see adverse reactions (6), clinical pharmacology (12.2), nonclinical pharmacology (13.1)]. the safety and efficacy of demerol injection in patients less than 18 years of age have not been established. the safety and effectiveness of meperidine in pediatric patients has not been established. literature reports indicate that meperidine has a slower elimination rate in neonates and young infants compared to older children and adults. neonates and young infants may also be more susceptible to the effects, especially the respiratory depressant effects. if meperidine use is contemplated in neonates or young infants, any potential benefits of the drug need to be weighed against the relative risk of the patient. elderly patients (aged 65 years or older) may have increased sensitivity to meperidine. in general, use caution when selecting a dosage for an elderly patient, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy. respiratory depression is the chief risk for elderly patients treated with opioids, and has occurred after large initial doses were administered to patients who were not opioid-tolerant or when opioids were co-administered with other agents that depress respiration. titrate the dosage of demerol injection slowly in geriatric patients and monitor closely for signs of central nervous system and respiratory depression [see warnings and precautions (5.2)] . meperidine is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function. accumulation of meperidine and/or its active metabolite, normeperidine, can also occur in patients with hepatic impairment. elevated serum levels have been reported to cause central nervous system excitatory effects. meperidine should therefore be used with caution in patients with hepatic impairment. titrate the dosage of demerol injection slowly in patients with hepatic impairment and monitor closely for signs of central nervous system and respiratory depression. accumulation of meperidine and/or its active metabolite, normeperidine, can occur in patients with renal impairment. meperidine should therefore be used with caution in patients with renal impairment. titrate the dosage of demerol injection slowly in patients with renal impairment and monitor closely for signs of central nervous system and respiratory depression. demerol injection contains meperidine, a schedule ii controlled substance. demerol injection contains meperidine, a substance with high potential for misuse and abuse, which can lead to the development of substance use disorder, including addiction [see warnings and precautions (5.1)]. misuse is the intentional use, for therapeutic purposes, of a drug by an ‎individual in a way other than prescribed by a healthcare provider or for ‎whom it was not prescribed.‎ abuse is the intentional, non-therapeutic use of a drug, even once, for its desirable psychological or physiological effects. drug addiction is a cluster of behavioral, cognitive, and physiological phenomena that may include a strong desire to take the drug, difficulties in controlling ‎drug use (e.g., continuing drug use despite harmful consequences, giving ‎a higher priority to drug use than other activities and obligations), and ‎possible tolerance or physical dependence.‎ misuse and abuse of demerol injection increases risk of overdose, ‎which may lead to central nervous system and respiratory depression, ‎hypotension, seizures, and death. the risk is increased with concurrent ‎abuse of demerol injection with alcohol and/or other cns depressants. abuse of and addiction to opioids in some ‎individuals may not be accompanied by concurrent tolerance and ‎symptoms of physical dependence. in addition, abuse of opioids can occur ‎in the absence of addiction.‎ all patients treated with opioids require careful and frequent reevaluation for signs of misuse, abuse and addiction, because use of opioid analgesic products carries the risk of addiction even under appropriate medical use. ‎patients at high risk of demerol injection abuse include those with a ‎history of prolonged use of any opioid, including products containing meperidine, those with a history of drug or alcohol abuse, or those who use demerol injection in ‎combination with other abused drugs. “drug-seeking” behavior is very common in persons with substance use disorders. drug-seeking tactics include emergency calls or visits near the end of office hours, refusal to undergo appropriate examination, testing, or referral, repeated “loss” of prescriptions, tampering with prescriptions, and reluctance to provide prior medical records or contact information for other treating healthcare provider(s). “doctor shopping” (visiting multiple prescribers to obtain additional prescriptions) is common among people who abuse drugs and people with substance use disorder. preoccupation with achieving adequate pain relief can be appropriate behavior in a patient with inadequate pain control. demerol injection, like other opioids, can be diverted for nonmedical use into illicit channels of distribution. careful record-keeping of prescribing information, including quantity, frequency, and renewal requests, as required by state and federal law, is strongly advised. proper assessment of the patient, proper prescribing practices, periodic reevaluation of therapy, and proper dispensing and storage are appropriate measures that help to limit abuse of opioid drugs. risks specific to abuse of demerol injection abuse of demerol injection poses a risk of overdose and death. the risk is increased with concurrent abuse of demerol injection with alcohol and/or other cns depressants. parenteral drug abuse is commonly associated with transmission of infectious diseases such as hepatitis and hiv. both tolerance and physical dependence can develop during use of opioid therapy. tolerance is a physiological state characterized by a reduced response to a drug after repeated administration (i.e., a higher dose of a drug is required to produce the same effect that was once obtained at a lower dose). physical dependence is a state that develops as a result of a physiological adaptation in response to repeated drug use, manifested by withdrawal signs and symptoms after abrupt discontinuation or a significant dose reduction of a drug. withdrawal may be precipitated through the administration of drugs with opioid antagonist activity (e.g., naloxone), mixed agonist/antagonist analgesics (e.g., pentazocine, butorphanol, nalbuphine), or partial agonists (e.g., buprenorphine). physical dependence may not occur to a clinically significant degree until after several days to weeks of continued use. demerol injection should not be abruptly discontinued in a physically-dependent patient [see dosage and administration (2.4)] . if demerol injection is abruptly discontinued in a physically-dependent patient, a withdrawal syndrome may occur, typically characterized by restlessness, lacrimation, rhinorrhea, perspiration, chills, myalgia, and mydriasis. other signs and symptoms also may develop, including irritability, anxiety, backache, joint pain, weakness, abdominal cramps, insomnia, nausea, anorexia, vomiting, diarrhea, or increased blood pressure, respiratory rate, or heart rate. infants born to mothers physically-dependent on opioids will also be physically-dependent and may exhibit respiratory difficulties and withdrawal signs [see use in specific populations (8.1)] . parenteral drug products should be inspected visually for particulate matter and discoloration prior to ‎administration, whenever solution and container permit. do not use if color is darker than pale yellow, if it ‎is discolored in any other way, or if it contains a precipitate. instructions for use - carpuject™ single-dose cartridge carpuject™ single-dose cartridges with luer lock are packaged in a slim-pak™ tamper detection package. note that a needle is not included. before use, read all instructions for using the carpuject™ syringe, which are contained in the product insert for‎ the reusable carpuject™ holder before use. carpuject™ single-dose cartridges are to be used only with carpuject™ holders. note: to prevent needlestick injuries, do not recap, purposely bend, or break by hand used ‎needles. do not recap, purposely bend, or break by hand blunt cannulas. instructions for use - nexject™ single-dose prefilled syringe note : to prevent needlestick injuries, do not recap, purposely bend, or break by hand used ‎needles. do not recap, purposely bend, or break by ‎hand blunt cannulas. distributed by hospira, inc., lake forest, il 60045 usa lab-1387-2.0 revised: 12/2023

Canada - English - Health Canada

hospira healthcare ulc - meperidine hydrochloride - solution - 50mg - meperidine hydrochloride 50mg - opiate agonists

Canada - English - Health Canada

hospira healthcare ulc - meperidine hydrochloride - solution - 50mg - meperidine hydrochloride 50mg - opiate agonists

Canada - English - Health Canada

hospira healthcare ulc - meperidine hydrochloride - solution - 75mg - meperidine hydrochloride 75mg - opiate agonists

Canada - English - Health Canada

hospira healthcare ulc - meperidine hydrochloride - solution - 100mg - meperidine hydrochloride 100mg - opiate agonists

Canada - English - Health Canada

hospira healthcare ulc - meperidine hydrochloride - solution - 100mg - meperidine hydrochloride 100mg - opiate agonists

United States - English - NLM (National Library of Medicine)

hospira, inc. - meperidine hydrochloride (unii: n8e7f7q170) (meperidine - unii:9e338qe28f) - demerol injection is indicated for preoperative medication, support of anesthesia, and obstetrical analgesia. demerol injection is indicated for the management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. limitations of use because of the risks of addiction, abuse, and misuse with opioids, even at recommended doses [see warnings and precautions (5.1)] , reserve demerol injection for use in patients for whom alternative treatment options [e.g., non-opioid analgesics or opioid combination products]: - have not been tolerated, or are not expected to be tolerated - have not provided adequate analgesia, or are not expected to provide adequate analgesia demerol injection should not be used for treatment of chronic pain. prolonged demerol injection use may increase the risk of toxicity (e.g. seizures) from the accumulation of the meperidine metabolite, normeperidine. demerol injection is contraindicated in patients with: - significant respiratory depressio