Pain trials

The uKxmotoxins have attracted much recent interest owing to their potential application in the treatment of chronic pain, exemplified by the success of w-conotoxin MVIIA (Ziconotide) in phase III clinical trials initiated by the US pharmaceutical company Neurex. Ziconotide also has potential applications in other conditions associated with regulation of calcium channels. As with all peptides, though, bioavailability considerations and possible side-effects mean that the mode of delivery needs careful consideration. In the current pain trials, an infusion pump is used for delivery of peptide direct into... 

Numerous neuropeptides are beheved to be involved with the transmission or inhibition of pain, and the hope is to utilize this approach as a strategy to induce analgesia. Substance P is reported to be a transmitter of nociceptive impulses (39), and therefore antagonists should be analgesic. Capsaicin [404-86-4], C2gH2yN02, is known to deplete substance P and cause analgesia (40), but its side effects are intolerable. Antagonists to bradykinin [58-82-2], a substance known to induce pain (41), have shown some success in preclinical trials. 

Selective AR agonists are undergoing clinical trials for cardiac arrhythmias and pain (Ai) cardiac imaging and inflammation (A2a) colon cancer, rheumatoid arthritis, psoriasis, and dry eye (A3). Selective AR antagonists are either in or advancing toward clinical trials for kidney disorders (Ax) Parkinson s disease (A2a) diabetes and asthma (A2B) cancer and glaucoma (A3). 

The first two selective COX-2 inhibitors to be marketed and subjected to in depth clinical trials were celecoxib and rofecoxib. Both compounds are as effective as standard NSAIDs in rheumatoid arthritis, osteoarthritis and for pain following orthopaedic or dental surgery. Gastrointestinal side effects were far fewer than with comparator diugs and in fact were no... 

Abrams DI, Jay CA et al (2007) Cannabis in painful HIV-associated sensory neuropathy a randomized placebo-controUed trial. Neurology 68(7) 515-521 Anderson TD, Davidovich A et al (1992) Peripheral neuropathy induced by 2 , 3 -dideoxycytidine. 

Dorfman D, Dalton A et al (1999) Treatment of painful distal sensory polyneuropathy in HIV-infected patients with a topical agent results of an open-label trial of 5% lidocaine gel. AIDS 13(12) 1589-1590... 

Herzberg U, Sagen J (2001) Peripheral nerve exposure to HIV viral envelope protein gpl20 induces neuropathic pain and spinal gliosis. J Neuroimmunol 116(l) 29-39 Herzmann C, Johnson MA et al (2005) Long-term effect of acetyl-L-carnitine for antiretroviral toxic neuropathy. HIV Clin Trials 6(6) 344-350... 

Kemper CA, Kent G et al (1998) Mexiletine for HIV-infected patients with painful peripheral neuropathy a double-blind, placebo-controUed, crossover treatment trial. J Acquir Immune Defic Syndr Hum Retrovirol 19(4) 367-372... 

Kieburtz K, Simpson D et al (1998) A randomized trial of amitriptyline and mexiletine for painful neuropathy in HIV infection. AIDS Clinical Trial Group 242 Protocol Team. Neurology... 

Shlay JC, Chaloner K et al (1998) Acupuncture and amitriptyline for pain due to HIV-related peripheral neuropathy a randomized controlled trial. Terry Beim Community Programs for Clinical Research on AIDS. JAMA 280(18) 1590-1595... 

Simpson DM, Olney R et al (2000) A placebo-controlled trial of lamotrigine for painful HIV-associated neuropathy. Neurology 54(11) 2115-2119 Simpson DM, Katzenstein D et al (2001) Plasma carnitine in HIV-associated neuropathy. AIDS 15(16) 2207-2208... 

Gabepentin is an antiepileptic drug that has analgesic activity in neuropathic pain states from varying origins. Two recent randomised controlled trials of gabapentin in... 

Only one study to date has been conducted on the treatment of acute pancreatitis with antioxidants. Clemens et al. (1991) were unable to show any difference in the incidence or severity of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis in a prospective, randomized, double-blind, placebo-controlled trial of allopurinol. However, Salim (1991) performed a similar trial of the effect of allopurinol and DMSO in patients with pain from recurrent pancreatitis, and found significant benefit. On the basis that depletion of antioxidants is important in the pathogenesis of chronic pancreatitis, the administration of a cocktail of antioxidants was assessed for its effect on pain in this disease. Treatment with a combination of organic selenium, d-carotene, vitamins C and E, and methionine was of benefit in the initial pilot study, and in a placebo-controlled trial (San-dilands etal., 1990 Uden et al., 1990). 

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