Articles: pain-clinics.
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Although pain assessment is a vital preliminary step towards the satisfactory control of cancer pain, data on the prevalence of different pain syndromes are rare. In a prospective study of 2266 cancer patients, we assessed localisations, aetiologies and pathophysiological mechanisms of the pain syndromes. Thirty percent of the patients presented with 1, 39% with 2 and 31% with 3 or more distinct pain syndromes. ⋯ The main pain syndrome was also coded according to the IASP Classification of Chronic Pain. Regions and systems affected by the main pain syndrome showed large variation depending on the site of cancer origin, whereas temporal characteristics, intensity and aetiology were not markedly influenced by the cancer site. The variety of pain syndromes evaluated in our patients confirms the importance of comprehensive pain assessment prior to treatment.
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According to the German Drug Law of 1976 the present status of scientific knowledge regarding the benefit/risk-ratio of combination analgesics was reevaluated and is summarized taking the fixed combination of paracetamol plus acetylsalicylic acid as an example. The extensive discussion of the responsible committee for reevaluation of drugs B-3 (Neurology/Psychiatry) at the German Federal Institute of Health (Bundesgesundheitsamt) led to the following results as viewed by the involved members: - the fixed combination has its pharmacological rationale (secure detoxification, even with high single doses; (over)additive analgesic effect in experimental models. - the benefit of the fixed combination is given by a potentially lower liver toxicity as proven with experimental models and by an (over)additive efficacy in cancer pain or headache. - combination-specific risks surpassing the ones of the single substances are not recognizable. ⋯ Even though the clinical efficacy has been proven only in few specific studies the evaluation of the benefit/risk-ratio appears to be positive regarding the not recognizable combination-specific risks. The combination is recommended for acute use.
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alpha(2)-Adrenoceptor agonists like clonidine, dexmedetomidine, and ST-91, inhibit nociceptive reflex activity predominantly by a spinal mode of action. They mimic the action of the inhibitory transmitter noradrenaline, which is released from the terminals of bulbospinal monoaminergic pathways. The inhibition by noradrenaline is due partly to hyperpolarization of the postsynaptic neuronal membrane; however, the selective antinociceptive effect of the alpha(2)-adrenoceptor agonists results from reduction of the release of the excitatory transmitters such as glutamate and substance P, blockade of the binding of substance P to spinal neurones, and enhancement of the action of the inhibitory transmitter, 5-hydroxytryptamine. ⋯ Moreover, impulse conduction in C fibres of peripheral nerves is far more reduced by these compounds than that in A fibres. Antinociceptive effects are reported to occur in various models of clinical pain, e.g. the formalin test, adjuvans-induced arthritis, autotomy following deafferentation, and "hyperalgesia" after nerve ligation. Therefore, the mechanisms involved in antinociception may also be responsible for the analgesia produced by alpha(2)-adrenoceptor agonists.
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Disability is a central aspect in the assessment of chronic pain patients. Disability questionnaires in German (developed or adapted) are examined and selected for different purposes. The "Funktionsfragebogen Hannover" and the "Pain Disability Index" are recommended for both research and clinicalapplication while the "Sickness Impact Profile" is suitable only for research purposes. ⋯ There are some empirical data for three of them. Only the "Inventory of Familial Adaptability and Cohesion" has achieved a certain degree of empirical maturity. Further research and developmental activity in this area of pain assessment are urgently needed.