Pindolol, a beta-adrenoceptor blocker/5-hydroxytryptamine(1A/1B) antagonist, enhances the analgesic effect of tramadol
by
Rojas-Corrales MO, Ortega-Alvaro A,
Gibert-Rahola J, Roca-Vinardell A, Mico JA
Department of Neuroscience,
Neuropsycopharmacology Unit,
University of Cadiz, Plz. Fragela 9,
11003, Cadiz, Spain
Pain 2000 Nov 1; 88(2):119-124

ABSTRACT

The ability of pindolol, a beta-adrenoceptor blocker/5-hydroxytryptamine(1A/1B) antagonist, to enhance the clinical antidepressant response to selective serotonin re-uptake inhibitors is generally attributed to a blocking of the feedback that inhibits the serotoninergic neuronal activity mediated by somatodendritic 5-hydroxytryptamine (5-HT)(1A) autoreceptors. The current study examined the ability of pindolol to enhance the analgesic effect of tramadol, an atypical centrally-acting analgesic agent with relatively weak opioid receptor affinity and which, like some antidepressants, is able to inhibit the re-uptake of 5-HT in the raphe nuclei. Racemic pindolol (2 mg/kg, s.c.), rendered analgesic a non-effective acute dose of tramadol (10-40 mg/kg, i.p.) in two nociceptive tests: a hot plate test in mice and a plantar test in rats. Moreover, (+/-)8-OH-DPAT (0.125-1 mg/kg, s.c.), a selective 5-HT(1A) agonist, reduces the analgesic effect of tramadol in the same tests. These results suggest an implication of the somatodendritic 5-HT(1A) receptors in the analgesic effect of tramadol and open a new adjuvant analgesic strategy for the use of this compound.

Tramadol
Methadone
Tramadol: dosage
Immune response
Tramadol and analgesia
Tramadol and acute pain
Tramadol versus morphine
Tramadol versus oxycodone
Official prescribing indications
Tramadol as an antidepressant
Tramadol: risk/benefit analysis
Tramadol, morphine and the stomach
Pharmacokinetics and pharmacodynamics
Tramadol, depression and Parkinson's disease

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