Adrenergic beta-Antagonists ; analysis ; Analgesics, Opioid ; analysis ; Chromatography, High Pressure Liquid ; methods ; Humans ; Metoprolol ; analysis ; Tramadol ; analysis

BACKGROUNDOpioid switching is a therapeutic maneuver to improve analgesic response and/or reduce adverse side effects although the underlying mechanisms remain unknown. The µ-opioid receptor (MOR) has an important role in mediating the actions of morphine and other analgesic agents. This study is aimed at exploring the changes of MOR in the periaqueductal gray (PAG) in rats when morphine is substituted for equianalgesic fentanyl.

METHODSForty rats were randomly assigned to five treatment groups: 7 days normal saline group (N group), 7 days fentanyl group (F group), 7 days morphine group (M group), 7 days morphine and 7 days fentanyl-switching group (MF group), and 14 days morphine group (MM group). Rats repeatedly received subcutaneous injections of morphine sulfate (10 mg/kg) or equianalgesic fentanyl sulfate (0.1 mg/kg) twice daily. Rats' antinociceptive response to thermal pain was evaluated by the tail flick latency assay. MOR mRNA and protein expression in the PAG were measured using RT-PCR and Western blotting analyses respectively.

RESULTSThis study showed that after morphine was substituted with fentanyl on day 8, the tail flick latency (TFL) increased from (3.9 ± 0.4) seconds to (11.4 ± 0.4) seconds. The results also demonstrated that both MOR mRNA and protein expression in the PAG of rats in the MF group were less than that in the M group (P < 0.05) but more than that in MM group (P < 0.05).

CONCLUSIONSEquianalgesic fentanyl was still antinociceptive effective in rats with morphine tolerance, which may be due to the switching from morphine to fentanyl attenuating the decline of MOR expression in the PAG of rats.

Analgesics, Opioid ; pharmacology ; Animals ; Drug Tolerance ; Fentanyl ; pharmacology ; Male ; Morphine ; pharmacology ; Periaqueductal Gray ; chemistry ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Receptors, Opioid, mu ; analysis ; genetics

BACKGROUND: Coughing is a side effect of opioids that is rarely studied. Here, we evaluated the incidence of remifentanil induced coughing during anesthesia induction in an attempt to identify its risk factors and to examine the preventive effects of lidocaine and salbutamol. METHODS: A total of 237 patients scheduled to undergo general anesthesia were allocated randomly into three groups. Group C received no medication, while Group L received 2% lidocaine at 0.5 mg/kg intravenously 1 minute prior to remifentanil infusion and Group S inhaled one metered aerosol puff of salbutamol 15 minutes prior to entering the operating room. Remifentanil was infused at 5 ng/ml by target controlled infusion and coughing was measured for five minutes and graded as none, mild, moderate, or severe based on the number of coughs. RESULTS: The incidences of coughing were 30.4%, 25.3%, and 35.4% in Groups C, L, and S, respectively. The incidences, onset times, and severity of coughing did not differ significantly among groups. In addition, multivariate analysis showed that non-smoking and a lower body weight were risk factors of remifentanil-induced coughing (odds ratio, 8.13; P = 0.024, 1.11, and 0.004, respectively). CONCLUSIONS: The incidence of remifentanil-induced coughing was 30%. A total of 0.5 mg/kg lidocaine and 1 metered aerosol puff of salbutamol did not prevent coughing. Non-smoking and low body weight were found to be risk factors of remifentanil-induced coughing.
Albuterol ; Analgesics, Opioid ; Anesthesia ; Anesthesia, General ; Body Weight ; Cough ; Humans ; Incidence ; Lidocaine ; Multivariate Analysis ; Operating Rooms ; Piperidines ; Risk Factors

The paper reports the establishment of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) for simultaneous analysis of 11 opiates in hair samples, and the study of presence of opiates in the hair of active heroin addicts. About 20 mg of decontaminated and pulverized hair sample was hydrolyzed with buffer solution for 30 min, in the presence of morphine-d3 and acetylmorphine-d6 used as internal standards, and then extracted with the mixture of dichlormethane and isopropanol, separated by the Allure PFP propyl column with a mobile phase consisting of acetonitrile and 20 mmol L(-1) ammonium acetate buffer, and then analyzed by LC-MS/MS. Multiple reaction monitoring (MRM) mode was used to analyze 11 opiates. Eleven opiates showed a fairly good linearity over the corresponding range (r > 0.996 0). The detection limits were less than 0.05 ng mg(-1). The recoveries were between 47.2% and 110%, and the deviations of intra- and inter-day precision were less than 14%. Heroin, acetylmorphine, morphine, codeine, acetylcodeine and hydrocodone were detected in hair samples of 21 herion addicts. The developed method shows high sensitivity and selectivity, and is suitable for the simultaneous analysis of 11 opiates in hair samples and identify legal and illegal use of opiates.
Analgesics, Opioid ; analysis ; Chromatography, Liquid ; methods ; Codeine ; analogs & derivatives ; analysis ; Hair ; chemistry ; Heroin ; analysis ; Humans ; Hydrocodone ; analysis ; Limit of Detection ; Morphine ; analysis ; Morphine Derivatives ; analysis ; Sensitivity and Specificity ; Substance Abuse Detection ; methods ; Tandem Mass Spectrometry ; methods

Opioids are the one of the most commonly used drugs to control cancer pain all over the world. But, we should not overlook the potential risk of opioid intoxication because they have well-known detrimental side effects. The opioid intoxication can be diagnosed thorough various clinical manifestations. The altered mental status, respiratory depression, and miosis is very representative clinical features although these symptoms don't always appear together. Unfortunately the opioid-toxidrome can be varied. A 42 years old man came to our emergency room after taking about 900 mg morphine sulfate per oral. He was nearly alert and his respiration was normal. Even though his symptoms didn't deteriorated clinically, serial arterial blood gas analysis showed increase in PaCO2. So we decided to use intravenous naloxone. Soon, he was fully awaked and his pupils size was increased. After a continuous infusion of intravenous naloxone for 2 hours, PaCO2 decreased to normal range and his pupil size also returned to normal after 12 hours. Though the levels of serum amylase and lipase increased slightly, his pancreas was normal according to the abdominal computed tomography. He had nausea, vomit, and whole body itching after naloxone continuous infusion, but conservatively treated. We stopped the continuos infusion after 1 day because his laboratory results and physical examinations showed normal. As this case shows, it is very important to prescribe naloxone initially. If you suspect opioid intoxication, we recommend the initial use of naloxone even though a patient has atypical clinical features. In addition, we suggest intranasal administration of naloxone as safe and effective alternative and it's necessary to consider nalmefene that has a longer duration for opioid intoxication.
Administration, Intranasal ; Amylases ; Analgesics, Opioid ; Blood Gas Analysis ; Emergencies ; Humans ; Lipase ; Miosis ; Morphine ; Naloxone ; Naltrexone ; Nausea ; Pancreas ; Physical Examination ; Porphyrins ; Pruritus ; Pupil ; Reference Values ; Respiration ; Respiratory Insufficiency

BACKGROUND: Significant analgesic synergy is obtained when opioids are combined with dilute local anesthetics, but serious side effects of intraspinal opioid can develope. The purpose of this study was to see how much does additional fentanyl make change of hemodynamics and analgesic dermatome according to variation of local anesthetic concentration. METHODS: Thirty patients were divided into three groups who were receiving epidurally 0.33% bupivacaine 15 ml(group 1), 0.33% bupivacaine 15 ml including fentanyl 100 g(group 2), 0.25% bupivacaine 15 ml including fentanyl 100 g(group 3) at the C7-T1 interspace. We observed mean arterial blood pressure, pulse rate and arterial blood gas analysis to be changed. Evaluation of the onset and duration of analgesic action by pin prick test were taken. Also side effects and complications were checked. RESULTS: Decreases of mean arterial blood pressure was statistically significant between 10 and 120 minutes in group 1, between 10 and 50 minutes in group 2, between 10 and 40 minutes in group 3 after drug administration. Decreases of pH and increases of PaCO2 were statistically significant between 30 and 60 minutes in group 1, between 30 and 120 minutes in group 2, 3 after drug administration. In three groups, number of analgesic dermatome was maximal at 40 minutes after drug administraion. The duration of analgesia in C8 dermatome was 153 29 minutes in group 1, 168 21 minutes in group 2, 131 31 minutes in group 3. Inadvertant dural puncture was developed in one patient. Transient pruritus, nausea/vomiting and solmnolence were developed in group 2, 3. CONCLUSIONS: Three groups provided sufficient analgesia for operation. fentanyl affects on hemodynamics, ventilation but not on number of maximal analgesic dermatome. Also it produces side effects such as, mild pruritus, somnolence, nausea/vomiting.
Analgesia ; Analgesics, Opioid ; Anesthesia, Epidural* ; Anesthetics ; Anesthetics, Local ; Arterial Pressure ; Blood Gas Analysis ; Bupivacaine* ; Fentanyl ; Heart Rate ; Hemodynamics ; Humans ; Hydrogen-Ion Concentration ; Pruritus ; Punctures ; Ventilation

Physostigmine has been used to counteract somnolence or coma induced by different types of phamacological agent, such as anticholinergics, opioids, ketamine and tricyclic antidepressants. In this study, we have assesed the effects of physostigmine on arousal after laryngomicroscopic surgery under enflurane-N2O general anesthesia and the effects of muscle relaxants. Forty patients were divided randomly into four groups such as I (succinylcholine only), II (vecuronium only), III(succinylcholine and physostigmine) and IV(vecuronium and physostigmine). Physostigmine 1mg was administered intravenously at the end of operation. We evaluated the recovery time of spontaneous respiration, gag reflex, pain response, extubation, eye opening on command and orientation after the end of operation. We also observed the end tidal CO2 and expired enflurane concentration with SARA(R) spectrometry at the end of operation and at the time of each recovery parameters returned . Our results revealed that physostigmine groups(group III and IV) were recovered more rapidly in the recovery time of eye opening to verbal command and orientation than non-physostigmine groups(group I and II ). But there was no difference in recovery time of spontaneous respiration, gag reflex, pain response and extubation. Therefore, we concluded that physostigmine 1 mg, i.v. has the effects of early arousal after short and deep general anesthesia and it did not show any specific complications such as bradycardia, bronchospasm, nausea and vomiting.
Analgesics, Opioid ; Anesthesia, General ; Antidepressive Agents, Tricyclic ; Arousal* ; Bradycardia ; Bronchial Spasm ; Cholinergic Antagonists ; Coma ; Enflurane ; Equidae ; Humans ; Ketamine ; Nausea ; Physostigmine* ; Reflex ; Respiration ; Spectrum Analysis ; Vomiting

BACKGROUND: The aim of this study was to evaluate the effects of respiratory depression of IV-PCA using morphine which has potent respiratory depression or nalbuphine which has less potent respiratory depression among opioids. METHODS: Forty patients were divided into two groups; Group M was used morphine, and Group N was used nalbuphine as a drug for IV-PCA. When patient emerges from general anesthesia, Group M was given initial bolus of 0.1 ml/kg of 0.1% morphine solution and connected Basal Bolus PCA infusor R containing morphine 50 mg per 40 ml in normal saline. Group N, similarly Group M, was given initial bolus of 0.1 ml/kg of 0.1% nalbuphine solution, and connected PCA infusor containing nalbuphine 50 mg per 40 ml in normal saline. To compare respiratory depression, arterial blood gas analyses were done preoperatively and at 1, 6 and 12 hour after IV-PCA. Simultaneously, analgesic and side effects were evaluated. RESULTS: There were no remarkable respiratory depression such as hypercarbia(PaCO2 > 50 mmHg), hypoxemia(PaO2 < 60 mmHg) and slow respiratory rate in both groups. Analgesic and side effects were similar in both groups. CONCLUSIONS: We conclude that IV-PCA using morphine or nalbuphine is relatively effective and safe method for the postoperative pain control. Ordinarily, IV-PCA dose not induce respiratory depression unless overdose in careless or mistaken mishaps are developed.
Analgesia, Patient-Controlled* ; Analgesics, Opioid ; Anesthesia, General ; Blood Gas Analysis ; Humans ; Infusion Pumps ; Morphine* ; Nalbuphine* ; Pain, Postoperative ; Passive Cutaneous Anaphylaxis ; Respiratory Insufficiency* ; Respiratory Rate

Adult ; Analgesics, Opioid ; pharmacology ; Female ; Fentanyl ; pharmacology ; Humans ; In Vitro Techniques ; Interleukin-6 ; blood ; Male ; Morphine ; pharmacology ; Narcotics ; pharmacology ; Tumor Necrosis Factor-alpha ; analysis

Micellar liquid chromatography (MLC) is a reversed phase liquid chromatography with mobile phases containing surfactant above its critical micellar concentration (CMC). The basic mechanism and advantages of MLC in physicochemical analysis were reviewed, and its applications in analysis of drugs, barbiturates, benzodiazepines were chiefly introduced in this paper. MLC is a potential method to toxicological analysis due to strong selectivity, wide application scope and easy biological samples, etc.
Analgesics, Opioid/analysis* ; Barbiturates/chemistry* ; Benzodiazepines/chemistry* ; Chromatography, Liquid/methods* ; Humans ; Hypnotics and Sedatives/chemistry* ; Micelles ; Reproducibility of Results ; Sensitivity and Specificity ; Solvents/chemistry* ; Surface-Active Agents/chemistry*