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Clinical Pharmacology and Therapeutics Apr 1980Whether meperidine metabolism is affected by pregnancy or immaturity has not been clearly established. This is of interest because meperidine is commonly given during... (Comparative Study)
Comparative Study
Whether meperidine metabolism is affected by pregnancy or immaturity has not been clearly established. This is of interest because meperidine is commonly given during labor for pain relief and the fetus receives the drug in utero. Moreover, animals studies suggest that the hormones of pregnancy contribute to decreased activity of the drug-metabolizing enzymes. In our study gas chromatography was used to determine the concentrations of meperidine and normeperidine in the plasma and urine of pregnant and nonpregnant women and in the urine of neonates. Plasma samples were collected for at least 3 hr after a dose of meperidine intravenously to calculate the kinetic parameters of meperidine disposition; urine samples were collected for 3 days. In contrasts to reports on animals, we found that pregnant and nonpregnant women readily metabolize meperidine to normeperidine and excrete both in a similar manner. No significant differences were demonstrated between any of the kinetic constants for peripartum and nonpregnant subjects. The neonate was found to metabolize and excrete these drugs less rapidly.
Topics: Adolescent; Adult; Biotransformation; Female; Humans; Infant, Newborn; Kinetics; Labor, Obstetric; Meperidine; Pregnancy
PubMed: 7357807
DOI: 10.1038/clpt.1980.68 -
Anesthesia and Analgesia Jul 2014Induction of therapeutic hypothermia is often complicated by shivering. Nefopam, a nonsedative benzoxazocine analgesic, reduces the shivering threshold (triggering core... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Induction of therapeutic hypothermia is often complicated by shivering. Nefopam, a nonsedative benzoxazocine analgesic, reduces the shivering threshold (triggering core temperature) with minimal side effects. Consequently, nefopam is an attractive drug for inducing therapeutic hypothermia. However, nefopam alone is insufficient and thus needs to be combined with another drug. Meperidine also reduces the shivering threshold. We therefore determined whether the combination of nefopam and meperidine is additive, infra-additive, or synergistic on the shivering threshold.
METHODS
Ten volunteers were each studied on 4 randomly assigned days. In random order, they were given the following treatments: (1) control, no drug; (2) nefopam to a target concentration of 0.1 μg/mL; (3) meperidine to a target concentration of 0.1 μg/mL; and (4) both nefopam and meperidine at target concentrations of 0.1 μg/mL each. Lactated Ringer's solution at 4°C was infused to decrease core temperature while mean skin temperature was kept near 30.5°C. The core temperature that increased oxygen consumption >25% defined the shivering threshold.
RESULTS
Nefopam reduced the shivering thresholds by 0.7°C ± 0.3°C compared with no drug. Meperidine reduced the shivering thresholds by 0.4°C ± 0.3°C compared with no drug. When combined, the shivering threshold decreased by only 0.6°C ± 0.4°C, which was about half what would have been expected based on the individual effects of each drug (P < 0.001). The effect of combined nefopam and meperidine on the shivering threshold was thus infra-additive.
CONCLUSIONS
The combination of nefopam and meperidine should be avoided for induction of therapeutic hypothermia. Better options would be combinations of drugs that are at least additive or even synergistic.
Topics: Adult; Drug Synergism; Drug Therapy, Combination; Humans; Hypothermia, Induced; Meperidine; Nefopam; Shivering
PubMed: 24806137
DOI: 10.1213/ANE.0000000000000193 -
Canadian Anaesthetists' Society Journal Jul 1977We studied the interaction of meperidine and halothane in 24 unmedicated, spontaneously breathing dogs. Intramuscular (i.m.) injections of meperidine, 2.75 mg/kg, 5.5...
We studied the interaction of meperidine and halothane in 24 unmedicated, spontaneously breathing dogs. Intramuscular (i.m.) injections of meperidine, 2.75 mg/kg, 5.5 mg/kg and 11.0 mg/kg reduced the minimal alveolar concentration (MAC) of halothane required for anaesthesia. The magnitude and duration of MAC depression were dose related. Plasma meperidine concentrations following an i.m. injection of 2.75 mg/kg were lower in the awake, unsedated dogs than in the dogs anaesthetized with halothane.
Topics: Anesthesia; Animals; Dogs; Dose-Response Relationship, Drug; Drug Interactions; Female; Halothane; Male; Meperidine; Time Factors
PubMed: 890559
DOI: 10.1007/BF03005450 -
General Dentistry 1987
Topics: Humans; Injections, Intravenous; Meperidine; Thrombophlebitis
PubMed: 3471638
DOI: No ID Found -
Annals of Internal Medicine Apr 1983
Topics: Central Nervous System Diseases; Humans; Meperidine; Myoclonus; Seizures
PubMed: 6838077
DOI: 10.7326/0003-4819-98-4-548 -
Anesthesiology Jun 1994Although meperidine has been used for patient-controlled analgesia both intravenously (PCIA) and epidurally (PCEA), these routes have not been compared, and many studies... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
BACKGROUND
Although meperidine has been used for patient-controlled analgesia both intravenously (PCIA) and epidurally (PCEA), these routes have not been compared, and many studies have suggested that there is no advantage to the epidural route for administration of lipophilic opioids.
METHODS
A randomized, double-blind, crossover study was conducted for 24 h after cesarean section to compare the analgesic efficacy, side effects, patient satisfaction, drug use, and plasma drug concentrations with meperidine administered either as PCIA or as PCEA. Two groups, stratified for time of cesarean section during epidural anesthesia, postoperatively received either PCEA (group 1) or PCIA (group 2) with identical variables for 12 h before crossing to the other route for an additional 12 h.
RESULTS
Results from 45 patients showed a similar speed of analgesic onset but, subsequently, significantly lower pain scores both at rest and with coughing in those receiving PCEA (P = 0.0001). Nausea and pruritus scores did not differ between the groups in the first 12 h postoperatively, but sedation scores were significantly higher with PCIA (P = 0.0001). Patient satisfaction scores and preference significantly favored PCEA (P = 0.0001), with almost 90% of participants preferring the epidural route. Meperidine use was reduced approximately 50% with PCEA (P = 0.0001), and plasma meperidine and normeperidine concentrations were significantly lower (P = 0.0001).
CONCLUSIONS
We conclude that after cesarean section, PCEA with meperidine produces high-quality pain relief with few side effects and has significant advantages over PCIA meperidine. With the caveat that neonatal effects in breast-feeding mothers have yet to be evaluated, it can be highly recommended in this population.
Topics: Adult; Analgesia, Obstetrical; Analgesia, Patient-Controlled; Cesarean Section; Double-Blind Method; Drug Eruptions; Female; Humans; Injections, Epidural; Injections, Intravenous; Meperidine; Pain, Postoperative; Patient Satisfaction; Pregnancy; Pruritus
PubMed: 8010473
DOI: 10.1097/00000542-199406000-00014 -
Die Pharmazie Jun 2018Oral fluid assays for quantifying drugs are useful in forensic toxicology and drug monitoring. Compared with blood and urine specimens, oral fluid collection is simple,...
Oral fluid assays for quantifying drugs are useful in forensic toxicology and drug monitoring. Compared with blood and urine specimens, oral fluid collection is simple, non-invasive, and more difficult to adulterate. Therefore, we investigated whether meperidine and its metabolites could be detected in oral fluid and whether there was a predictable relationship between oral fluid and plasma concentrations. Male New Zealand white rabbits (n = 10) were administered meperidine hydrochloride (20 mg/kg, intravenous). Then, plasma and oral fluid were collected at various time points up to 10 h after administration. We developed a simple and sensitive gas chromatography-mass spectrometry method for the determination of meperidine and normeperidine in oral fluid and plasma. We estimated the apparent pharmacokinetic parameters for meperidine in oral fluid and plasma and determined the ratio and correlation between oral fluid and plasma concentrations. The results demonstrate that this method has excellent specificity, linearity, precision, and recovery. Meperidine and normeperidine were detected in both body fluids; meperidine was the most abundant analyte in oral fluid. The oral fluid-to-plasma drug concentration ratios did not differ significantly over time (p > 0.05). In addition, oral fluid and plasma levels of meperidine and normeperidine were significantly correlated over time (r = 0.713 and 0.725, respectively; p < 0.05). These results provide context for interpreting meperidine and metabolite concentrations in oral fluid and support the utility of oral fluid as an alternative matrix in clinical and forensic testing.
Topics: Administration, Intravenous; Analgesics, Opioid; Animals; Drug Monitoring; Gas Chromatography-Mass Spectrometry; Male; Meperidine; Rabbits; Reproducibility of Results; Time Factors
PubMed: 29880084
DOI: 10.1691/ph.2018.8014 -
Journal of Clinical Pharmacology Apr 1981To determine the effect of chlorpromazine on the serum concentration-time curve and metabolism of meperidine, 10 healthy volunteers were injected on two separate days in... (Clinical Trial)
Clinical Trial
To determine the effect of chlorpromazine on the serum concentration-time curve and metabolism of meperidine, 10 healthy volunteers were injected on two separate days in a two-way crossover design with 26 mg/m2 meperidine hydrochloride combined with either 30 mg/m2 chlorpromazine or a placebo. The subjects demonstrated the same serum meperidine concentration-time curves after meperidine plus placebo and meperidine plus chlorpromazine. The excretion of the metabolites normeperidine and normeperidinic acid, however, showed a significant increase with the meperidine-chlorpromazine combination. A marked lethargy was observed after the administration of the meperidine-chlorpromazine combinations in most subjects, which was quite debilitating and may have resulted from the alteration of meperidine metabolism by chlorpromazine. The meperidine-chlorpromazine combination also caused a greater mean depression of the systolic and diastolic pressures than the meperidine-placebo combination. The differences in the blood pressure and symptomatology were significant and represent a potential toxicity that may result from the use of the chlorpromazine-meperidine combination.
Topics: Adult; Blood Pressure; Chlorpromazine; Drug Interactions; Humans; Meperidine; Metabolic Clearance Rate
PubMed: 7240435
DOI: 10.1002/j.1552-4604.1981.tb05691.x -
JAMA
Topics: Adult; Brain Diseases; Dyskinesia, Drug-Induced; Humans; Male; Meperidine
PubMed: 3941530
DOI: No ID Found -
JAMA Dec 1974
Comparative Study
Topics: Chronic Disease; Humans; Meperidine; Morphine; Pain
PubMed: 4479657
DOI: 10.1001/jama.230.11.1512d