Drug therapy in patients with chronic low back pain is a major challenge for physicians. One of the problems is the lacking knowledge in prediction of drug efficacy in a chosen patient. Usually one of the classes of pain medication is given to patients with a similar clinical picture, although different pain mechanisms may be responsible for this clinical picture. Another reason for variable drug efficacy are genetic polymorphisms, this may be the reason why an unique drug produces different responses (from a lacking analgesic effect up to excessive effect or side-effects. Quantitative sensory testing is a method that documents alterations in the pain perception system. Linking genetic polymorphisms to quantitative sensory testing may give us a tool for anticipation of drug efficacy.
Name: Oxycodone 15mg
Description: 15mg single administration p.o.Type: Drug1
Name: Clobazam
Description: 20mg single administration p.o.Type: Drug2
Name: Imipramine
Description: 75mg single administration p.o.Type: Drug3
Name: Tolterodine
Description: 1 mg single administration p.o.Type: Drug4
Allocation: Randomized
Crossover Assignment
There is one SNP
Methods Quantitative sensory testing: Heat pain threshold and tolerance, Ice water testing with central modulation of nociceptive input (DNIC), electrical pain detection and temporal summation (skin probe), pressure algometry with pain detection and threshold Drugs investigated: Imipramine, Oxycodone, Clobazam Blood samples: pharmacogenetics: Cytochrome variants CYP2D6, CYP2C19, CYP3A4, COMT haplotypes, CGH-1 variants, A118G of mu opioid receptor gene variants pharmacokinetics: kinetics of imipramine and desipramine --- A118G ---