Chronic low back pain

Opioids are the benchmark against which other biliary tract analgesics are assessed. Historically, the distinction between opioids used for biliary tract pain (BTP) has been based upon differential effects on Oddi's sphincter. NSAIDs provide good analgesic effect, lack untoward effects on biliary tract pressure, and (perhaps through anti-inflammatory activity) seem to reduce the rate of progression from uncomplicated biliary colic to acute cholecystitis. Drugs acting at the cholecystokinin receptor may also be useful in acute treatment of BTP. Spasmolytic and anticholinergic drugs have been investigated as treatment for biliary colic. Calcium channel blockers are known to relax biliary tract smooth muscle. For BTP, the most potent agent in this class appears to be nifedipine.There is currently insufficient evidence to support use of nifedipine for acute treatment of BTP, and its outpatient efficacy is hindered by suboptimal pain relief and frequent headache.