In most parts of the world, the majority of cancer patients suffer an advanced stage of the disease, which unfortunately is not responsive to curative treatment. Nearly 75% of patients with advanced cancer experience pain, very often in conjunction with many other symptoms, such as asthenia, anorexia and malnutrition, skin problems, dry mouth or thirst, constipation, nausea or vomiting, anxiety, low mood, depression, confusion and sleeplessness (1,2). For such patients, the only available management is palliative care, which focuses mainly on pain relief (3).
Palliative care is an approach that improves the quality of life of patients through the prevention and relief of suffering. To meet the multiple and varying needs of the patients, it is believed that the care should be holistic, multidisciplinary, and family - as well as patient - centred. The aims of palliative care are achieved by:
• providing relief from pain and other distressing symptoms;
• affirming life and regarding dying as a normal process;
• intending neither to hasten nor to postpone death;
• integrating the psychological and spiritual aspects of patient care;
• offering a support system to help patients live as actively as possible until death;
• offering a support system to help the family to cope during the patient's illness and during bereavement;
• using a team approach to address the needs of patients and their families, including bereavement counselling, if indicated;
• enhancing quality of life, and possibly also positively influencing the course of illness; and
• starting palliative care early in the course of illness, in conjunction with other therapies that are intended to prolong life, such as chemotherapy or radiation therapy, and including those investigations needed to better understand and manage distressing clinical complications (4).
Palliative care is still a neglected area worldwide and several million cancer patients suffer needlessly every day as a result (5).Most cancer patients in developing countries receive inadequate palliative care and less than 10% of the resources committed to cancer control in these countries are available to them (1). Palliative care remains far from satisfactory, mainly because of:
• an absence of national policies on cancer pain relief and other aspects of palliative care;
• the lack of education for health care providers, policy-makers, administrators and the general public;
• the concern that the medical use of morphine and related drugs will fuel the problem of drug abuse in a community and result in increased restrictions on prescription and supply;
• limitations on the supply and distribution of the drugs needed for the relief of pain and other symptoms, particularly in developing countries;
• restrictions imposed by the adoption of regional, district or hospital formularies, which contain insufficient drugs for the control of pain and other symptoms;
• the shortage of professional health care workers empowered to prescribe analgesics and other drugs for palliative care; and
• the lack of financial resources for research and development in palliative care (1).
Pain relief is a key component of a comprehensive palliative care programme. Relief from cancer pain can be achieved in about 90% of patients, but unfortunately pain is often poorly managed. Pain relief may be achieved by drug use, but may also include various other means: psychological approaches, pathological processes (e.g. nerve degeneration) and modification of daily activities. The pharmacological approach to the palliative care of cancer patients uses a variety of drugs for managing symptoms. These include non-opioid analgesics (mild analgesics and nonsteroidal anti-inflammatory drugs), opioids for moderate to severe pain, ulcer-healing drugs, antispasmodics, corticosteroids, bronchodilators, laxatives, antiemetics, antifungals, antidepressants and hypnotics among others.
Data from studies by Miaskowski, Du pen and Ward et al. (6 - 8) indicate that one of the main factors contributing to the undertreatment of cancer pain is the patients' lack of adherence to the therapeutic regimen. The study by Ward et al. (8) showed that a third of the patients they monitored delayed or omitted many prescribed doses. This reflects the fact that patients often take their doses at intervals longer than those prescribed, commonly longer by hours, but sometimes by days and occasionally by weeks. The clinical and economic consequences of these lapses in dosing are uniquely difficult to measure due to the complexity of treatment and the severity of disease.
Because more than 90% of palliative care is provided on an outpatient basis, it is critically important for clinicians to know how their patients adhere to their regimen for analgesics or other palliative therapies, and if possible, they should also know which effective interventions are available for improving adherence. The aim of this chapter is to summarize the available literature on adherence to palliative care and provide answers to some of these questions.