title: Concomitant use of tramadol and venlafaxine - evaluation of antidepressant-like activity and other behavioral effects in rats.
abstract: BACKGROUND
  The aim of this study was to evaluate antidepressant-like effect (Porsolt test), locomotor activity and motor coordination of joint administration of tramadol (TRM) and venlafaxine (VEN) in rats.
  
  
  METHODS
  The tests were performed on male Wistar rats after single and chronic treatment (7 and 14 days) with TRM intraperitoneally (ip) and VEN orally (po) administered once a day. The controls were given 0.5% carboxymethylcellulose (CMC) solution (0.5 ml per rat, ip and po).
  
  
  RESULTS
  It was found that combination of TRM (5 mg/kg ip) with VEN (20 mg/kg po) caused an increased antidepressant effect compared to TRM and VEN administered alone, with no effect on locomotor activity or motor coordination in rats, which may be of clinical significance. It was also observed that reduced time of active swimming of animals in Porsolt test with an increased dose (10 and 20 mg/kg) and time of administration (7 and 14 days) of TRM were correlated with a decreased locomotor activity in rats. It may indicate the development of tolerance to TRM's antidepressant effect in rats during chronic treatment with doses higher than 5 mg/kg.
  
  
  CONCLUSIONS
  It can be expected that combination of low doses of TRM and VEN could potentially be feasible and relatively safe in cases with acute pain with co-existing depression, however, further investigations are needed.
authors: Department of Clinical Pharmacy and Biopharmacy, Poznan University of Medical Sciences, Sw. Marii Magdaleny 14, PL 61-861 Poznań, Poland. d.szkutnik@wp.pl
authors: Danuta
authors: D
authors: Szkutnik-Fiedler
authors: Krzysztof
authors: K
authors: Kus
authors: Monika
authors: M
authors: Balcerkiewicz
authors: Edmund
authors: E
authors: Grześkowiak
authors: Elżbieta
authors: E
authors: Nowakowska
authors: Kinga
authors: K
authors: Burda
authors: Piotr
authors: P
authors: Ratajczak
authors: Czesław
authors: C
authors: Sadowski
mesh_terms: D000284:Administration, Oral; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D018687:Antidepressive Agents, Second-Generation / Q000008:administration & dosage / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects*; D003511:Cyclohexanols / Q000008:administration & dosage / Q000494:pharmacology*; D004334:Drug Administration Schedule; D004347:Drug Interactions; D004361:Drug Tolerance; D007274:Injections, Intraperitoneal; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D011597:Psychomotor Performance / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D017367:Selective Serotonin Reuptake Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D013550:Swimming; D013997:Time Factors; D014147:Tramadol / Q000008:administration & dosage / Q000494:pharmacology*; D000069470:Venlafaxine Hydrochloride
chemical_list: D000701:Analgesics, Opioid; D018687:Antidepressive Agents, Second-Generation; D003511:Cyclohexanols; D017367:Selective Serotonin Reuptake Inhibitors; D014147:Tramadol; D000069470:Venlafaxine Hydrochloride