Stefan Grond

Validation of World Health Organization Guidelines for cancer pain relief: a 10-year prospective study.

&NA; This paper reports on the experience gained using World Health Organization Guidelines for cancer pain relief over a 10‐year period in an anaesthesiology‐based pain service associated with a palliative care programme. The course of treatment of 2118 patients was assessed prospectively over a period of 140,478 treatment days. Non‐opioid analgesics (WHO step I) were used on 11%, weak opioids (WHO step II) on 31% and strong opioids (WHO step III) on 49% of treatment days. Administration was via the enteral route on 82% and parenterally on 9% of treatment days. On the remaining days, either spinally applied opioids (2%) or other treatments (6%) were utilised. Fifty‐six percent of the patients were treated with morphine. Morphine dose escalation was observed in about one‐half of the patients being cared for until death, whereas the other half had stable or decreasing doses over the course of treatment. Co‐analgesics were administered on 37% of days, most often antidepressants (15%), anticonvulsants (13%) and corticosteroids (13%). AdjuBANts to treat symptoms other than pain were prescribed on 79% of days, most commonly laxatives (42%), histamine‐2‐receptor antagonists (39%) and antiemetics (35%). In addition, palliative antineoplastic treatment was performed in 42%, nerve blocks in 8%, physiotherapy in 5%, psychotherapy in 3% and TENS in 3% of patients. A highly significant pain reduction was achieved within the 1st week of treatment (P < 0.001). Over the whole treatment period, good pain relief was reported in 76%, satisfactory efficacy in 12% and inadequate efficacy in 12% of patients. In the final days of life, 84% rated their pain as moderate or less, while 10% were unable to give a rating. Analgesics remained constantly effective in all 3 steps of the WHO ladder. Other clinical symptoms were likewise significantly reduced at 1 week after initial assessment, with the exception of neuropsychiatric symptoms. During the course of treatment, the latter were the major symptoms on 23% of days, followed by nausea (23%), constipation (23%) and anorexia (20%). Our results emphasise once again the marked efficacy and low rate of complications associated with oral and parenteral analgesic therapy as the mainstay of pain treatment in the palliative care of patients with adBANced cancer. Wide dissemination of WHO guidelines among doctors and healthcare workers is thus necessary to effect a clear improvement in the treatment of the many patients suffering from cancer pain in the clinical and home setting.

Assessment of cancer pain: a prospective evaluation in 2266 cancer patients referred to a pain service

&NA; 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 majority of patients had pain caused by cancer (85%) or antineoplastic treatment (17%); 9% had pain related to cancer disease and 9% due to aetiologies unrelated to cancer. Pain could be classified as originating from nociceptors in bone (35%), soft tissue (45%) or visceral structures (33%) or otherwise as of as neuropathic origin (34%). In most patients, pain syndromes were located in the lower back (36%), abdominal region (27%), thoracic region (23%), lower limbs (21%), head (17%) and pelvic region (15%). 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.

Prevalence and pattern of symptoms in patients with cancer pain: A prospective evaluation of 1635 cancer patients referred to a pain clinic

In a prospective study, the prevalence of 15 physical symptoms and symptom groups was evaluated in 1635 cancer patients referred to a pain clinic. In addition to pain, patients suffered an average of 3.3 symptoms: insomnia (59%), anorexia (48%), constipation (33%), sweating (28%), nausea (27%), dyspnea (24%), dysphagia (20%), neuropsychiatric symptoms (20%), vomiting (20%), urinary symptoms (14%), dyspepsia (11%), paresis (10%), diarrhea (6%), pruritus (6%), and dermatological symptoms (3%). While symptom prevalence was influenced by tumor site, pain intensity, and opioid treatment, only a minor relationship was seen between symptoms and gender, age, or tumor stage. The data emphasize that it is not sufficient to simply address pain during the treatment of patients with cancer pain; a more global approach to symptom management is necessary.

Clinical Pharmacokinetics of Transdermal Opioids Focus on Transdermal Fentanyl

Transdermal delivery allows continuous systemic application of opioids through the intact skin. This review analyses the pharmacokinetic properties of transdermal opioid administration in the context of clinical experience, with a focus on fentanyl.A transdermal therapeutic system (TTS) for fentanyl has been developed. The amount of fentanyl released is proportional to the surface area of the TTS, which is available in different sizes. After the first application of a TTS, a fentanyl depot concentrates in the upper skin layers and it takes several hours until clinical effects are observed. The time from application to minimal effective and maximum serum concentrations is 1.2 to 40 hours and 12 to 48 hours, respectively. Steady state is reached on the third day, and can be maintained as long as patches are renewed. Within each 72-hour period, serum concentrations decrease gradually over the second and third days. When a TTS is removed, fentanyl continues to be absorbed into the systemic circulation from the cutaneous depot. The terminal half-life for TTS fentanyl is approximately 13 to 25 hours. The interindividual variability of serum concentrations, partly caused by different clearance rates, is markedly larger than the intraindividual variability.The effectiveness of TTS fentanyl was first demonstrated in acute postoperative pain. However, the slow pharmacokinetics and large variability of TTS fentanyl, together with the relatively short duration of postoperative pain, precluded adequate dose finding and led to inadequate pain relief or, especially, a high incidence of respiratory depression; such use is now contraindicated. Conversely, in cancer pain, TTS fentanyl offers an interesting alternative to oral morphine, and its effectiveness and tolerability in this indication has been demonstrated by a number of trials. Its usefulness in chronic pain of nonmalignant origin remains to be confirmed in controlled trials.In general, TTS fentanyl produces the same adverse effects as other opioids, mainly sedation, nausea, vomiting and constipation. In comparison with oral morphine, TTS fentanyl causes fewer gastrointestinal adverse events. The risk of hypoventilation is comparatively low in cancer patients.Sufentanil and buprenorphine may also be suitable for transdermal delivery, but clinical results are not yet available. Transdermal morphine is only useful if applied to de-epithelialised skin. However, iontophoresis may allow transdermal administration of opioids, including morphine, with a rapid achievement of steady state concentrations and the ability to adjust delivery rates. This would be beneficial for acute and/or breakthrough pain, and initial clinical trials are in progress.

Assessment and treatment of neuropathic cancer pain following WHO guidelines

Neuropathic pain syndromes are one of the major problems of cancer pain treatment. The present study surveys 593 cancer patients treated by a pain service following the WHO guidelines for relief of cancer pain. Of these, 380 presented with nociceptive, 32 with neuropathic and 181 with mixed (nociceptive and neuropathic) pain. In patients with nociceptive, mixed and neuropathic pain, the average duration of evaluated pain treatment was 51, 53 and 38 days, respectively. Non-opioid or opioid analgesics were given to 99%, 96% and 79%, antidepressants to 8%, 25% and 19%, anticonvulsants to 2%, 22% and 38% and corticosteroids to 26%, 35% and 22% of patients, respectively. Systemic analgesia was supported by palliative antineoplastic treatment (48%, 56% and 38% of patients), nerve blocks (3%, 6% and 6%), psychotherapy (3%, 7% and 3%), physiotherapy (6%, 12% and 13%) and transcutaneous electric nerve stimulation (1%, 6% and 6%). Analgesic treatment resulted in a significant pain relief in all groups of patients, as the mean pain intensity (NRS) decreased from 66 (nociceptive), 65 (mixed) and 70 (neuropathic) on admission to 26, 30 and 28 after 3 days and 18, 17 and 21 at the end of survey. The total outcome of pain treatment was not predicted by the designation to nociceptive, mixed or neuropathic pain. In conclusion, neuropathic cancer pain is not intractable and can be relieved in the majority of patients by treatment following the WHO guidelines.

A long-term survey of morphine in cancer pain patients

We surveyed 550 cancer patients who experienced pain and were treated with morphine for a total of 22,525 treatment days. Sufficient pain relief was achieved during more than 80% of this time using an average oral morphine dose of 82.4 mg--significantly lower than other studies. The use of this low dose, which was possible due to the concomitant administration of nonopioids and specific coanalgesics in most patients, resulted in a low incidence of side effects. Constipation and nausea/vomiting were the most common of these side effects. Physical dependence posed no practical problem in discontinuation of morphine treatment. Long-term opioid intake and development of tolerance did not appear to be linked; an increase in morphine dosage was most often explained by progression of the terminal disease. Addiction was a negligible problem, with only one observed case.

Constipation and the use of laxatives: a comparison between transdermal fentanyl and oral morphine

Constipation and the use of laxatives were investigated in patients with chronic cancer pain treated with oral morphine and transdermal fentanyl in an open sequential trial. Forty-six patients were treated with slow-release morphine 30–1000 mg/day for 6 days and 39 of these patients were switched to transdermal fentanyl 0.6–9.6 mg/day with a conversion ratio of 100:1. Median fentanyl doses increased from 1.2 to 3.0 mg/day throughout the 30-day transdermal treatment period. Twenty-three patients completed the study. Two patients died from the basic disease while treated with transdermal fentanyl, 12 patients were excluded for various reasons, and not enough data for evaluation were available for two patients. Mean pain intensity decreased slightly after conversion although the number of patients with breakthrough pain or requiring immediate-release morphine as a rescue medication was higher with transdermal fentanyl. The number of patients with bowel movements did not change after the opioid switch but the number of patients taking laxatives was reduced significantly from 78–87% of the patients per treatment day (morphine) to 22–48% (fentanyl). Lactulose was used mainly and was reduced most drastically, but other laxatives were also used less frequently. In this study transdermal fentanyl was associated with a significantly lower use of laxatives compared to oral morphine. The difference in the degree of constipation between the two analgesic regimens should be confirmed in a randomized double-blind study that takes into account both constipation and use of laxatives.

A Risk-Benefit Assessment of Tramadol in the Management of Pain

SummaryTramadol is a cyclohexanol derivative with μ-agonist activity. It has been used as an analgesic for postoperative or chronic pain since the late 1970s, and became one of the most popular analgesics of its class in Germany. International interest has been renewed during the past few years, when it was discovered that tramadol not only acts on opioid receptors, but also inhibits serotonin (5-hydroxytryptamine; 5-HT) and noradrenaline (norepinephrine) reuptake. This review aims to provide a risk-benefit assessment of tramadol in the management of acute and chronic pain syndromes.Tramadol has been used intraoperatively as part of balanced anaesthesia. Such use is under discussion, however, as it was associated with a high incidence of intraoperative recall and dreaming, and postoperative respiratory depression has been described after intraoperative administration of high doses.Postoperatively, intravenous and intramuscular tramadol has been used with good efficacy. Analgesic doses were comparable with pethidine (meperidine) and 10 times higher than morphine. Nausea and vomiting were the most frequently reported adverse effects. In controlled studies, haemodynamic and respiratory parameters were only minimally impaired. The risk of severe respiratory depression in typical dosages is negligible in comparison with other opioids used for postoperative pain management.Tramadol has been used with good results for the management of labour pain without respiratory depression of the neonate. It was also effective for the treatment of pain from myocardial ischaemia, ureteric colic and acute trauma.Good results have been published for cancer pain management with tramadol in several studies. The potential for abuse or addiction seems to be minimal, and serious complications have not been reported. For patients with severe pain, the efficacy of morphine is superior, and most patients with adequate analgesia from tramadol had to be changed to a more potent opioid after a few weeks due to increased nociceptive input during tumour progression. Tramadol can be recommended as a safe and efficient drug for step II according to the World Health Organization guidelines for cancer pain management.

Adverse Effects of Systemic Opioid Analgesics

SummaryAdverse effects of opioids are multiple. They are most often receptor-mediated and inseparable from their desired effects. The most severe mishaps with opioids are related to their respiratory depressant effect, which is widely influenced by factors such as pain, previous opioid experience and awareness. Other relevant central nervous system effects of opioids include cough suppression, nausea and vomiting, rigidity, pruritus and miosis.The cardiovascular adverse effects of opioids are mainly related to histamine release and differ widely between agonists and agonist-antagonists. Gastrointestinal effects such as constipation, reflux and spasms of the bile duct are well described. Adverse effects on endocrine, immunological and haematological functions are possible, while allergic reactions are extremely rare.The adverse effects of long term use are overestimated. Systemic toxicity is negligible and development of tolerance is minimal while treating pain. In the clinical setting of pain control, addiction and withdrawal do not pose significant problems. Nevertheless, the possible effects of opioids on the unborn child should always be considered.Overall, opioids show a good record of safety. Their use should not be unduly limited by unfounded fears of adverse effects, but these effects should be avoided by anticipation and prevention.

Transdermal fentanyl and initial dose-finding with patient-controlled analgesia in cancer pain. A pilot study with 20 terminally ill cancer patients

&NA; This pilot study evaluated the efficacy and side effects of a combination of initial patient‐controlled analgesia (PCA) for dose‐finding with transdermal fentanyl administration. Twenty inpatients, requiring strong opioids for severe cancer pain, received intravenous fentanyl on an on‐demand basis over a 24‐h period. The amount of fentanyl administered was then used as a guideline for selecting a suitable transdermal therapeutic system (TTS) on the 2nd day, which remained in place for 3 days. The size of 2nd TTS, being used from day 5 to 7, was adjusted according to the amount of supplementary intravenous fentanyl doses on day 3. From day 4 to 7 intravenous fentanyl was stopped, and subcutaneous morphine was made available as a rescue medication. A standardized adjuvant medication was allowed. Pain intensity, pain relief, quality of sleep, mood, general state of health, activity, mobility, rescue morphine consumption and side effects were assessed using a diary after baseline pain and symptoms were recorded. Vital functions were monitored and fentanyl plasma levels were measured daily in 15 patients. The use of TTS fentanyl in combination with initial dose titration using PCA gave rapid and statistically significant pain relief. Patient compliance and acceptance were excellent. In the absence of severe side effects the main complaints were dryness of the mouth and constipation. Increasing pain intensity and increasing supplementary morphine requirements as well as decreasing plasma fentanyl levels on day 7 may indicate that conversion ratios from intravenous to transdermal administration should be increased or that TTS should be changed earlier. Special indications for this combination may be in patients with dysphagia or vomiting, where pain management could be facilitated.