Search Results

You are looking at 1 - 10 of 11 items for

  • Keyword: tramadol x
Clear All Modify Search
Open access

U. Kaka, Y.M. Goh, L.W. Chean and H.C. Chen


Electroencephalography (EEG) has been reported as an objective, non-invasive and stress free technique for nociceptive studies. Electrical stimuli can be used to evaluate the efficacy of centrally acting agents. Peripheral nerve stimulator can be a good and cheap source of electric stimulus for studies of nociception, and studies evaluating analgesic effect of drugs under EEG. In this study suitability of peripheral nerve stimulator, and milliamperage for nociceptive studies under electroencephalography were evaluated. Six dogs were subjected to electric stimulus of 20, 40, 60 and 80 milliamperes (mAs) before and after tramadol administration at 4 mg/kg IV. Electroencephalograph was recorded during electric stimulus prior tramadol (pre-tramadol) and during electric stimulus after tramadol (post-tramadol) under minimal anaesthesia. Anaesthesia was induced with propofol and maintained with halothane at a stable concentration between 0.85 and 0.95%. Pre-tramadol median frequency (MF) increased significantly (p<0.05) at 40, 60 and 80 mAs post-electric stimulus compared to baseline MF. No difference in pre-tramadol MF was observed between 60 and 80 mAs. Tramadol produced significant effect by depression of MF at all intensities. The effect was less evident at 80 mAs. The results revealed that tramadol produced evident effect between 20 and 60 mAs. Thus, it is concluded that nerve stimulator can be used with the current between 20 and 60 mAs for nociceptive studies.

Open access

I. Capík and O. Nagy


The objective of this study was to compare in clinical patients the analgesic effect of the centrally acting analgesics tramadol and buprenorphine in continuous intravenous anaesthesia (TIVA) with propofol. Twenty dogs undergoing prophylactic dental treatment, aged 2−7 years, weighing 6−27 kg, were included in ASA I. and II. groups. Two groups of dogs received intravenous (IV) administration of tramadol hydrochloride (2−1) or buprenorphine hydrochloride (0.2−1) 30 minutes prior to sedation, provided by midazolam hydrochloride (0.3−1) and xylazine hydrochloride (0.5 IV. General anaesthesia was induced by propofol (2−1) and maintained by a 120 minutes propofol infusion (0.2−1min−1). Oscilometric arterial blood pressure (ABP) measured in mm Hg, heart rate (HR), respiratory rate (RR), SAT, body temperature (BT) and pain reaction elicited by haemostat forceps pressure at the digit were recorded in ten minute intervals. The tramadol group of dogs showed significantly better parameters of blood pressure (P < 0.001), lower tendency to bradycardia (P < 0.05), and better respiratory rate (P < 0.001) without negative influence to oxygen saturation. Statistically better analgesia was achieved in the tramadol group (P < 0.001). Tramadol, in comparison with buprenorphine provided significantly better results with respect to the degree of analgesia, as well as the tendency of complications arising during anaesthesia.

Open access

Lin Li, Jing Dong, Dezhang Lu, Sheng Jiang, Dongqi Lin and Honggang Fan


Cats were injected with 2.4 mg/kg of tiletamine-zolazepam, 0.36 mg/kg of xylazine, and 0.8 mg/kg of tramadol, then blood was collected from their peripheral veins at 0.5, 1, 4, 8, 24, 48, 72, and 168 h after the injection. Before injection, the same cats were used as control group (0 h). Biochemical and haematological parameters were measured. The results revealed that the combination of the compounds produced good immobilisation, with minimal changes over time in biochemical and haematological parameters, which were within biologically acceptable limits.

Open access

P. Bodera, W. Stankiewicz, B. Antkowiak, M. Paluch, J. Kieliszek, J. Sobiech, R. Zdanowski, A. Wojdas, A. Siwicki and E. Skopińska-Różewska

Suppressive effect of electromagnetic field on analgesic activity of tramadol in rats

The electromagnetic fields (EMFs) have been shown to alter animal and human behavior, such as directional orientation, learning, pain perception (nociception or analgesia) and anxiety-related behaviors. The aim of this study was to evaluate the influence of electromagnetic fields of high-frequency microwaves on pain perception and anti-nociceptive activity of tramadol (TRAM) - analgetic effective in the treatment of moderate to severe acute and chronic pain states.

Electromagnetic fields exposures of a) 1500 MHz frequency and b) modulated, 1800 MHz (which is identical to that generated by mobile phones) were applied. Paw withdrawal latency (PWL) to thermal stimulus was measured in vehicle or tramadol (TRAM) treated animals before and after 30, 60 and 90 minutes from injections.

The differences in the level of pain (PWL) between control group and rats exposed to EMF alone in three measurements, were not observed. Tramadol alone significantly increased PWLs to thermal stimulus in comparison to vehicle results at 30 (p < 0.001) and 60 minutes (p < 0.05) after drug injection. EMF exposure of both frequencies transiently suppressed analgesic effect of tramadol, significantly reducing paw withdrawal latency in animals treated with this drug at 30 minutes from the drug injection.

Open access

Wantana Reanmongkol, Nattha Kaewnopparat and Chaveewan Ratanajamit


Background: Tramadol is a centrally acting analgesic drug. Rectal administration of tramadol is useful in the treatment of post-operative pain or malignant pain in cases where it cannot be administered orally. In Thailand, tramadol is available only as a capsule for oral use and as a solution for injection.

Objective: Develop tramadol hydrochloride rectal suppositories and rectal gel preparations.

Methods: Tramadol rectal suppository and rectal gel were prepared. Physicochemical properties (viscosity, gel strength, mucoadhesive force) and the in vitro release of tramadol hydrochloride were investigated from different bases (Witepsol H15, polyethylene glycol, poloxamer, and hydroxyethylcellulose). The analgesic activity of rectal tramadol hydrochloride using the hot plate test was evaluated in rats.

Results: Tramadol hydrochloride rectal gel using poloxamer was more mucoadhesive to the rectal mucous membrane than was the gel with the hydroxyethylcellulose base. Tramadol hydrochloride was released rapidly in vitro from both the Witepsol H15 and polyethylene glycol bases. It was completely released from the polyethylene glycol suppository base within 15 minutes. The amount of tramadol hydrochloride release from the Witepsol H15 suppository base was about 93% at 120 minutes. When using poloxamer or hydroxyethylcellulose as a rectal base, tramadol hydrochloride was released from both bases rapidly and completely released within 15 minutes. Administration of a tramadol hydrochloride suppository in rats exhibited a more pronounced analgesic effect with the polyethylene glycol base than with the Witepsol H15-based suppositories. The rectal gel had a less pronounced analgesic effect when made with the hydroxyethylcellulose base than with the poloxamer base.

Conclusion: Tramadol hydrochloride suppositories and rectal gels with different bases showed rapid and almost complete drug release from the bases, prolonging the latency of a nociceptive response in in vivo experiments.

Open access

M. Giorgi, S. Del Carlo, B. Łebkowska-Wieruszewska, C. Kowalski and G. Saccomanni

Pharmacokinetics of tramadol and metabolites after injective administrations in dogs

The aim of this study was to determine the pharmacokinetics of tramadol and its main metabolites after IV and IM injections. The pharmacokinetic cross-over study was carried out on 6 healthy male beagle dogs. Tramadol was administered by intravenous (IV) and intramuscular (IM) injection at 4 mg/kg. Tramadol and its main metabolites O-desmethyl-tramadol (M1), N-,N-didesmethyl-tramadol (M2) and N-,O-didesmethyl-tramadol (M5) concentrations were measured in plasma samples by a HPLC coupled with fluorimetric detection; pharmacokinetic evaluations were carried out with a compartmental and non-compartmental model for tramadol and its metabolites, respectively. The bioavailability of the drug, ranging between 84-102% (mean 92%), was within the generally accepted values for a positive bioequivalence decision of (80-125%). After the IM injection the mean plasma drug concentration peak was reached after a Tmax of 0.34 h with a Cmax of 2.52 μg/mL. No therapeutic relevant differences were observed between IM and IV administration. The minimal effective plasma concentration was reached after a few minutes and maintained for about 6-7 h in both administrations. M1 plasma concentration was low and the amounts of the other metabolites produced were analogous in both routes of administration. In conclusion, tramadol was rapidly and almost completely absorbed after IM administration and its systemic availability was equivalent to the IV injection. The different onset time and duration of action observed were very small and probably therapeutically irrelevant. The IM injection is a useful alternative to IV injection in the dog.

Open access

Lidia Cristina Chiţac, S. Beşchea Chiriac, Monica Neamţu, Delia Bulea and Veronica Bild


Experimental research followed by clinical studies have demonstrated the existence of several types of pain, thus the pain classification according to the mediation has widely extended. In addition, the study of the interactions with pharmacodynamic mechanism expanded very much during the last years; therefore in the new theories appear significant changes concerning synergism, addition and subadditivity in binary combinations. The investigations in this paper were aimed the demonstration of the antinociceptive of some drugs with anticonvulsant action and the analysis of their binary combinations with tramadol, using isobolar analysis. As model of nociception has been used the test of abdominal constrictive response in mouse induced by Zymosan A. the test substances were administered orally alone or in fixed proportion combinations. The data obtained were subjected to isobolar analysis. According to the statistical analysis the following have been observed: the binary combination tramadol-VA has proven to be synergistic (Zmix ⋋ Zadd, f = 0,5, p1 = 677, Tc =3.936, Tt = 3,529, c = 12.78, Ft = 4.46, p ⋋ 0.05), while the binary combination tramadol-CBZ has proven to be borderline additive (Z mix ⋋ Zadd).

Open access

Pramod Kumar, Sanjay Singh and Brahmeshwar Mishra

Development and biopharmaceutical evaluation of extended release formulation of tramadol hydrochloride based on osmotic technology

Extended release formulation of tramadol hydrochloride (TRH) based on osmotic technology was developed and evaluated. Target release profile was selected and different variables were optimized to achieve it. Formulation variables such as the level of swellable polymer, plasticizer and the coat thickness of semipermeable membrane (SPM) were found to markedly affect drug release. TRH release was directly proportional to the levels of plasticizer but inversely proportional to the levels of swellable polymer and coat thickness of SPM. Drug release from developed formulations was independent of pH and agitation intensity but dependent on osmotic pressure of the release media. In vivo study was also performed on six healthy human volunteers and various pharmacokinetic parameters (c max, t max, AUC 0-24, MRT) and relative bioavailability were calculated. The in vitro and in vivo results were compared with the performance of two commercial TRH tablets. The developed formulation provided more prolonged and controlled TRH release compared to the marketed formulation. In vitro-in vivo correlation (IVIVC) was analyzed according to the Wagner-Nelson method. The optimized formulation (batch IVB) exhibited good IVIV correlation (R = 0.9750). The manufacturing procedure was found to be reproducible and formulations were stable over 6 months of accelerated stability testing.

Open access

Ahmed Jalil Al-Safi and Yehya Kamal Al-Bayati


Four electrodes were synthesized based on molecularly imprinted polymers (MIPs). Two MIPs were prepared by using tramadol hydrochloride (TRH) as the template, acryl amide (AA) and 2-hydroxy ethyl meth acrylate (2-HEMA) as monomers, divinyl benzene as a cross linker, and benzoyl peroxide as initiator, respectively. The same composition was used to prepare non-imprinted polymers (NIPs), but without the template (Tramadol hydrochloride). Different plasticizers were employed to prepare the membranes; tris (ethyl hexyl) phosphate (TEHP), tri Butyl phosphate (TBP), di-octyl phthalate (DOP) and nitrobenzene (NB) in PVC matrix. The electrode characteristics and properties were studied, including: slope, detection limit, life time and linearity range. The results of selectivity coefficient measurements using amino acids as interfering species showed no effect on tramadol electrode response. The prepared electrodes were intended for use in determining tramadol in pharmaceutical samples

Open access

Rattanaporn Burimsittichai, Phoonsak Limraksasin, Cameron Paul Hurst and Somrat Charuluxananan



Catheter-related bladder discomfort (CRBD) is a distressing symptom after anesthesia.


To compare the efficacy of tramadol and ketamine to prevent CRBD after laparoscopic surgery.


After registration with the Thai Clinical Trial Registry (TCTR20140220001), we conducted a randomized controlled trial in 210 patients aged 18-70 years with American Society of Anesthesiologists physical status I or II undergoing elective laparoscopic surgery requiring bladder catheterization. These patients were randomly allocated into 1 of 3 groups: Group T received intravenous (i.v.) tramadol 1.5 mg/kg, Group K received i.v. ketamine 0.5 mg/kg, and Group P received i.v. saline as a placebo before catheterization. Patients received i.v. morphine for postoperative pain control. An anesthesiologist blinded to the randomization evaluated postoperative and CRBD pain severity using visual analog scales (VAS). The cumulative postoperative and CRBD pain was calculated by multiplying mean VAS scores by the hours of assessment.


Groups T and K had significantly less cumulative CRBD pain compared with placebo (P = 0.04 and 0.001, respectively). Cumulative postoperative pain, total 24-h morphine consumption, and adverse effects were comparable between groups. Group T had a significantly lower incidence of shoulder pain (7/67, 10%) than Group K (21/70, 30%), and Group P (24/70, 34%) 24 h after surgery (P = 0.006 and 0.001, respectively).


Tramadol 1.5 mg/kg and ketamine 0.5 mg/kg administered i.v. before bladder catheterization are both effective in reducing the 24-h cumulative postoperative CRBD after laparoscopic surgery without significant adverse effects. Tramadol also decreases the incidence of postlaparoscopy shoulder pain.