Opioids Switching with Transdermal Systems in Chronic Cancer Pain

<p>Abstract</p> <p>Background</p> <p>Due to tolerance development and adverse side effects, chronic pain patients frequently need to be switched to alternative opioid therapy</p> <p>Objective</p> <p>To assess the efficacy and tolerability of an alternative transdermally applied (TDS) opioid in patients with chronic cancer pain receiving insufficient analgesia using their present treatment.</p> <p>Methods</p> <p>A total of 32 patients received alternative opioid therapy, 16 were switched from buprenorphine to fentanyl and 16 were switched from fentanyl to buprenorphine. The dosage used was 50% of that indicated in equipotency conversion tables. Pain relief was assessed at weekly intervals for the next 3 weeks</p> <p>Results</p> <p>Pain relief as assessed by VAS, PPI, and PRI significantly improved (p < 0.0001) in all patients at all 3 follow up visits. After 3 weeks of treatment, the reduction in the mean VAS, PPI, and PRI scores in the fentanyl and buprenorphine groups was 68, 77, 74, and 69, 79, and 62%, respectively. Over the same time period the use of oral morphine as rescue medication was reduced from 27.5 ± 20.5 (mean ± SD) to 3.75 ± 8.06, and 33.8 ± 18.9 to 3.75 ± 10.9 mg/day in the fentanyl and buprenorphine groups, respectively. There was no significant difference in either pain relief or rescue medication use between the two patient groups The number of patient with adverse events fell during the study. After the third week of the treatment the number of patients with constipation was reduced from 11 to 5, and 10 to 4 patients in the fentanyl and buprenorphine groups, respectively. There was a similar reduction in the incidence of nausea and vomiting. No sedation was seen in any patient after one week of treatment.</p> <p>Conclusion</p> <p>Opioid switching at 50% of the calculated equianalgesic dose produced a significant reduction in pain levels and rescue medication. The incidence of side effects decreased and no new side effects were noted. Further studies are required to provide individualized treatment for patients according to their different types of cancer.</p

A complex interaction between glycine/NMDA receptors and serotonergic/noradrenergic antidepressants in the forced swim test in mice

Both clinical and preclinical studies demonstrate the antidepressant activity of the functional NMDA receptor antagonists. In this study, we assessed the effects of two glycine/NMDA receptor ligands, namely L-701,324 (antagonist) and d-cycloserine (a partial agonist) on the action of antidepressant drugs with different pharmacological profiles in the forced swim test in mice. Swim sessions were conducted by placing mice individually in glass cylinders filled with warmed water for 6 min. The duration of behavioral immobility during the last 4 min of the test was evaluated. The locomotor activity of mice was measured with photoresistor actimeters. L-701,324 and d-cycloserine given with reboxetine (administered in subeffective doses) did not change the behavior of animals in the forced swim test. A potentiating effect was seen when both tested glycine site ligands were given concomitantly with imipramine or fluoxetine in this test. The lesion of noradrenaline nerve terminals produced by DSP-4 neither altered the baseline activity nor influenced the antidepressant-like action of L-701,324 or d-cycloserine. The depletion of serotonin by p-CPA did not alter baseline activity in the forced swim test. However, it completely antagonized the antidepressant-like action produced by L-701,324 and d-cycloserine. Moreover, the antidepressant-like effects of imipramine, fluoxetine and reboxetine were abolished by d-serine, a full agonist of glycine/NMDA receptors. The present study demonstrates that glycine/NMDA receptor functional antagonists enhance the antidepressant-like action of serotonin, but not noradrenaline-based antidepressants and such their activity seems to depend on serotonin rather than noradrenaline pathway