Biomedical subjects
G W Hanks
Publications and source records attributed to G W Hanks.
Efficacy and pharmacokinetics of a new controlled-release morphine sulfate 200-mg tablet.
Nineteen of 25 patients (14 female) with advanced malignant disease completed a randomized controlled trial of a new high-dose (200 mg) tablet formulation of controlled-release morphine. Compared with the currently available 100-mg tablets there were no differences in pain severity or adverse effects with the new formulation. In four patients, full 12-hr plasma morphine concentration profiles at steady state were obtained and showed no significant differences between the same dose provided as 100-mg and 200-mg tablets in Cmax, tmax, or other pharmacokinetic indices.
Problem areas in pain and symptom management in advanced cancer patients.
Explore the source record for details and available documents.
Transdermal fentanyl in cancer pain: conversion from oral morphine.
Explore the source record for details and available documents.
Cancer pain and the importance of its control.
In 1985 there were almost 5 million deaths from cancer, and it is estimated that in 2015 there will be over 9 million, of which almost three-quarters will be in developing countries. Seventy to eighty per cent of these patients will experience moderate or severe pain at some stage of their illness and at present most of these will die in pain. This is true in spite of the fact that there is substantial evidence which shows that in as many as 80% of patients with cancer pain it is possible to obtain complete relief with orally administered analgesics, either alone or supplemented with co-analgesic (adjuvant) drugs. Management is based on the three-step analgesic ladder whereby the choice of analgesic (non-opioid, weak opioid, or strong opioid) is determined by the severity of pain. The main reasons for failure to achieve control of pain are inexperience and lack of knowledge of the simple principles of effective analgesic use, and in many countries the non-availability of strong opioid analgesics. The most important advances in management have been the simplification and refinement of analgesic treatment which have made relief of cancer pain more widely accessible to patients. The introduction of controlled-release oral formulations of morphine has had a considerable impact because they are convenient and simple to use. The recent development of a long-acting non-invasive transdermal delivery system for strong opioid administration promises a further step forward in terms of flexibility and convenience for cancer patients.
Control of common symptoms in advanced cancer.
In common with any medical problem, careful assessment and an analytical approach are the keystones to effective symptom control in advanced cancer. When dealing with such symptoms the multi-faceted pathophysiology must be considered, and due attention paid to the affective component of pain and other symptoms. Adequate care given to history taking and a knowledge of the likely pathogenesis of symptoms in advanced cancer can prevent unnecessary investigations and fruitless trials of inappropriate symptomatic remedies. The treatment chosen should be the simplest effective regimen tailored to the individual patient. The importance of explanation to the patient cannot be overstated and is an integral part of any treatment and the sole component of many. This paper reviews the management of common symptoms in advanced cancer (dyspnoea, nausea and vomiting, constipation, anorexia-cachexia syndrome, hypercalcaemia, confusion, insomnia and depression.
Pain management in cancer patients.
Cancer pain in general responds in a predictable way to analgesic drugs and drug therapy is the mainstay of treatment, successfully controlling pain in 70 to 90% of patients. Some pains do not respond so well but can usually be ameliorated by the judicious use of adjuvant analgesics, non-drug measures and the active involvement of the multi-disciplinary team.
Tranexamic acid and rectal bleeding.
Explore the source record for details and available documents.
Analgesics in cancer pain: current practice and beliefs.
Prescribing practices for patients with cancer pain among populations of doctors in the United Kingdom have been assessed by means of a postal questionnaire. The results indicate that amongst the sample of doctors completing the questionnaire the basic principles of pain control in cancer appear to be understood. Regular oral morphine or diamorphine are most often chosen with the dose being determined mainly by the severity of pain with no arbitrary upper limit. Fears of addiction and respiratory depression, and a relatively long prognosis no longer appear to be major deterrents to the use of strong opioid analgesics. These data indicate considerable shifts in opinion in the doctors responding to the questionnaire and these results and their implications for current and future teaching about the management of cancer pain are discussed.
Opioid-responsive and opioid-non-responsive pain in cancer.
Cancer pain in general responds in a predictable way to analgesic drugs and drug therapy is the mainstay of treatment, successfully controlling pain in 70-90% of patients. The two major problem areas are pain associated with nerve damage, and 'incident' (movement-related) bone pain. Nerve damage pain tends not to respond well to morphine or other opioids. The difficulty with severe incident pain is that if the dose of opioid is titrated sufficiently to relieve the pain on weight-bearing or on movement and is then given regularly at this level, it is too much for the patient at rest. The patient may then experience excessive side-effects at rest, but still have pain on movement. Other examples of pain which may be resistant to treatment with opioid analgesics are bladder and rectal tenesmus, pancreatic pain, and pain associated with decubitus ulcers or other superficial ulcers subjected to pressure or shearing forces. Management of non-opioid-responsive pain may include a variety of treatments involving adjuvant analgesic drugs and non-drug measures.
Opioid agonist-antagonist drugs in acute and chronic pain states.
The agonist-antagonist opioid analgesics are a heterogeneous group of drugs with moderate to strong analgesic activity comparable to that of the pure agonist opioids such as codeine and morphine but with a limited effective dose range. The group includes drugs which act as an agonist or partial agonist at one receptor and an antagonist at another (pentazocine, butorphanol, nalbuphine, dezocine) and drugs acting as a partial agonist at a single receptor (buprenorphine). These drugs can be classified as nalorphine-like or morphine-like. Meptazinol does not fit into either classification and occupies a separate category. Pentazocine, butorphanol and nalbuphine are weak mu-antagonists and kappa-partial-agonists. All three drugs are strong analgesics when given by injection: pentazocine is one-sixth to one-third as potent as morphine, nalbuphine is slightly less potent than morphine, and butorphanol is 3.5 to 7 times as potent. The duration of analgesia is similar to that of morphine (3 to 4 hours). Oral pentazocine is closer in analgesic efficacy to aspirin and paracetamol (acetaminophen) than the weak opioid analgesics such as codeine. Neither nalbuphine nor butorphanol is available as an oral formulation. At usual therapeutic doses nalbuphine and butorphanol have respiratory depressant effects equivalent to that of morphine (though the duration of such effects with butorphanol may be longer). Unlike morphine there appears to be a ceiling to both the respiratory depression and the analgesic action. All of these 3 drugs have a lower abuse potential than the pure agonist opioid analgesics such as morphine. However, all have been subject to abuse and misuse, and pentazocine (but not the others) is subject to Controlled Drug restrictions. Buprenorphine is a potent partial agonist at the mu-receptor, and by intramuscular injection is 30 times as potent as morphine. A ceiling to the analgesic effect of buprenorphine has been demonstrated in animals and it is also claimed in humans. However, there are no reliable data available to define the maximal dose of buprenorphine in humans. A practical ceiling exists for sublingual use in that the only available formulation is a 2 micrograms tablet and few patients will accept more than 3 or 4 of these in a single dose. The duration of analgesia is longer than that of morphine, at 6 to 9 hours. There have been suggestions that buprenorphine causes less respiratory depression than morphine, but viewed overall it appears that in equianalgesic doses the 2 drugs have similar respiratory depressant effects.(ABSTRACT TRUNCATED AT 400 WORDS)
Morphine pharmacokinetics and analgesia after oral administration.
The well established use of oral morphine in the treatment of chronic cancer pain has developed empirically and a knowledge of its pharmacokinetics is not necessary in order to use the drug effectively. However recent information about the pharmacokinetics of morphine may help resolve the controversy about oral to parenteral relative potency ratios, and may also in the future shed some light on the problem of patients whose pain does not respond to morphine.
CSF concentrations of morphine-6-glucuronide after oral administration of morphine.
Explore the source record for details and available documents.
Subcutaneous midazolam infusion in palliative care.
This article describes the use of a subcutaneous infusion of midazolam to control restlessness and agitation in 23 patients during the final stages of advanced cancer. Midazolam effectively controlled symptoms in 22 of the patients at an initial dose of 0.4-0.8 mg/hr rising to a mean maximum dose of 2.9 mg/hr. Midazolam mixed in the same syringe as diamorphine was well tolerated at injection sites. The wide dose range emphasizes the need for careful titration of dose for individual patients. At high doses, the volume of injection required presented some practical difficulties, but otherwise there were no major problems with this technique. Midazolam by subcutaneous infusion is a well-tolerated, safe and effective treatment for terminal restlessness and agitation, and deserves more extensive evaluation.
Long-term management of respiratory symptoms in advanced cancer.
Respiratory symptoms are a common cause of distress in patients with advanced cancer. Optimal palliative therapy requires careful assessment and the appropriate use of symptomatic measures in conjunction with specific antitumor treatments. The etiology and management of the three major respiratory symptoms, dyspnea, cough and hemoptysis, are described. The indications for antitumor treatments and surgical procedures are briefly outlined, and symptomatic treatments, including drug and nondrug measures, are discussed in detail.
Morphine: pharmacokinetics and clinical practice.
Explore the source record for details and available documents.
Drainage of malignant effusions.
Explore the source record for details and available documents.