Curr Opin Invest Dr
-
Neuropathic pain results from damage to the nervous system due to many diverse processes. It causes persistent, distressing pain that is reputedly unresponsive to conventional analgesics. ⋯ There is no single effective drug treatment and patients have been empirically treated with antidepressants and antiepileptics in the past. This review focuses on evidence from randomized controlled trials to assess the efficacy of the currently available drug treatments.
-
Endo (which acquired Algos in July 2000) has developed EN-3231, a combination of morphine and dextromethorphan, for the treatment of moderate-to-severe chronic pain. In October 1998, the FDA accepted for filing the company's NDA submission on EN-3231, which was submitted in August 1998. ⋯ The FDA requested a second pivotal trial, which Endo initiated promptly. Endo hoped to file its supplement to the NDA during 2002.
-
Gabapentin has been approved for the treatment of neuropathic pain in six European countries, New Zealand and Australia, and numerous countries in Latin America. By January 2001, Pfizer was preparing to file an NDA in the US for this indication; by October 2001, this NDA had been filed with the FDA. The drug is a GABA analog, but is not a GABA mimetic, although some neurons that respond to gabapentin are GABAergic. ⋯ Gabapentin is also a substrate for the large neutral amino acid transporter, and this may be the major route allowing gabapentin access to the CNS. Modulation of synaptic transmission between primary afferents and substantia gelatinosa neurons, and blockade of signal transduction, are two potential mechanisms of action, in addition to inhibition of glutamate release by voltage-sensitive calcium channels. In September 2001, Morgan Stanley predicted sales of US $1871 million in 2002 falling to US $413 million in 2006.