treatment with Tapentadol ER 100-250 mg twice daily or oxycodone HCl CR 20-50 mg twice daily was effective for the management of moderate to severe chronic osteoarthritis-related knee pain, with substantially lower incidences of gastrointestinal-related TEAEs associated with treatment with Tapentadol ER than with oxycodone CR.

Tapentadol ER (100 - 250 mg b.i.d.) effectively relieved moderate to severe chronic low back pain over 15 weeks and had better gastrointestinal tolerability than oxycodone HCl CR (20 - 50 mg b.i.d.).

Risperidone plus a mood stabilizer was more efficacious than a mood stabilizer alone, and as efficacious as haloperidol plus a mood stabilizer, for the rapid control of manic symptoms and was well tolerated.

Tapentadol PR (100-250 mg twice daily) was efficacious and provided efficacy that was similar to oxycodone HCl CR (20-50 mg twice daily) for the management of chronic osteoarthritis knee and low back pain, with a superior gastrointestinal tolerability profile and fewer treatment discontinuations.

Antibodies to neuropeptide receptors can be used to localize and characterize the receptors in tissues and cell lines. Two strategies were used to study the rat substance P receptor (SPR, NK-1) by immunological methods. First, a polyclonal antiserum was raised by immunizing rabbits with a peptide corresponding to the 15 amino acid residues (KTMTESSSFYSNMLA, SPR393-407) at the intracellular C-terminus of the rat SPR coupled to bovine thyroglobulin. An antiserum was obtained with a titer for half-maximal binding of 125I-SPR393-407 of 1:70,000. Nonradioactive SPR393-407 inhibited 50% of binding at a concentration of 10 pM. Binding of 125I-SPR393-407 to the antiserum was also displaced in a parallel manner by membrane proteins from tissues expressing high levels of the SPR (brain and submaxillary gland). Second, a chimeric SPR construct of a hydrophilic Flag peptide (DYKDDDDK) genetically engineered in sequence with the extracellular N-terminus of rat SPR was generated by polymerase chain reaction. The Flag-SPR chimera was expressed in rat kidney epithelial cells (KNRK) and judged to be fully functional, assessed by binding of 125I-substance P (apparent Kd of 5.63 nM) and calcium mobilization in response to substance P (EC50 of 0.66 nM). Antibodies to SPR393-407 and the Flag peptide stained the plasma membrane of KNRK cells expressing the native SPR or the Flag-SPR chimera. Staining was abolished by preincubation with SPR393-407 or the Flag peptide. Cells transfected with vector alone were unstained. The SPR antiserum recognized a broad protein band on Western blots of membranes prepared from cells expressing SPR but not from cells transfected with vector alone. The signal was quenched by preincubation of the antiserum with SPR393-407. By immunohistochemistry, the SPR antiserum was found to bind to neurons in the dorsal horn of the rat spinal cord and to ganglion cells in the myenteric plexus of the rat ileum near substance P-immunoreactive nerve fibers. Staining was abolished by preabsorption of the antiserum with SPR393-407. These antibodies can be used to localize the SPR in tissues and cells and to examine the function of the receptor in cell lines.