Oxycodone: a pharmacological and clinical review.

Oxycodone is a semi-synthetic opioid with an agonist activity on mu, kappa and delta receptors. Equivalence with regard to morphine is 1:2. Its effect commences one hour after administration and lasts for 12 h in the controlled-release formulation. Plasma halflife is 3-5 h (half that of morphine) and stable plasma levels are reached within 24 h (2-7 days for morphine). Oral bioavailability ranges from 60 to 87%, and plasma protein binding is 45%. Most of the drug is metabolised in the liver, while the rest is excreted by the kidney along with its metabolites. The two main metabolites are oxymorphone--which is also a very potent analgesic--and noroxycodone, a weak analgesic. Oxycodone metabolism is more predictable than that of morphine, and therefore titration is easier. Oxycodone has the same mechanism of action as other opioids: binding to a receptor, inhibition of adenylyl-cyclase and hyperpolarisation of neurons, and decreased excitability. These mechanisms also play a part in the onset of dependence and tolerance. The clinical efficacy of oxycodone is similar to that of morphine, with a ratio of 1/1.5-2 for the treatment of cancer pain. Long-term administration may be associated with less toxicity in comparison with morphine. In the future, both opioids could be used simultaneously at low doses to reduce toxicity. It does not appear that there are any differences between immediate and slow-release oxycodone, except their half-life is 3-4 h, and 12 h, respectively. In Spain, controlled-release oxycodone (OxyContin) is marketed as 10-, 20-, 40- or 80-mg tablets for b.i.d. administration. Tablets must be taken whole and must not be broken, chewed or crushed. There is no food interference. The initial dose is 10 mg b.i.d. for new treatments and no dose reduction is needed in the elderly or in cases of moderate hepatic or renal failure. Immediate-release oxycodone (OxyNorm) is also available in capsules and oral solution. Side effects are those common to opioids: mainly nausea, constipation and drowsiness. Vomiting, pruritus and dizziness are less common. The intensity of these side effects tends to decrease over the course of time. Oxycodone causes somewhat less nausea, hallucinations and pruritus than morphine.

Cutaneous malignant melanoma and sun exposure in Spain.

Cutaneous malignant melanoma has an increasing importance all over the world. However very few epidemiological studies have been published from Spain, and Spanish people have not become aware of the problem. This study was designed to examine sun exposure patterns and other related items among 116 consecutive patients with melanoma and 235 controls. Each subject answered a questionnaire covering the place of residence, sun exposure details and other risk factors, and underwent a skin examination. Continuous sun exposure due to residence or occupation was associated with an odds ratio (OR) of 2.0 (95% confidence interval [CI] = 1.2-3.3). People who lived in the city but spent 50% of their time in rural areas for holidays had an OR of 2.2 (95% CI = 1.3-3.8) when compared with those living in urban and rural areas. The OR for people who sunbathed more than 30 times a year was 1.8 (95% CI = 1.2-2.8), and outdoor leisure time was also associated with melanoma appearance when exposure was greater than 60 units in the last 2 years, with an OR of 3.0 (95% CI = 1.6-5.5); 1 unit is equivalent to total body sun exposure for at least 2 h. These OR estimates were adjusted for age, skin type and the number of naevi. Construction workers (OR = 1.6; 95% CI = 0.5-5.6) had increased risk after adjustment for skin type, age and freckle count (OR = 4.3; 95% CI = 1.8 9.9) or mole count (OR = 2.8; 95% CI = 1.4-5.8). Working as a farmer was a protective factor after adjustment (OR = 0.5; 95% CI = 0.3-0.8). The use of sunscreens was a protective factor against melanoma (OR = 2.6; 95% CI = 1.6-3.6 for non-users). Campaigns should focus on advising people to avoid sun exposure in sunny places and to use sunscreens every time they are exposed to the sun.

[Sclerosing cholangitis, papillary stenosis and B-cell lymphoma in a patient with acquired immunodeficiency syndrome]. / Colangitis esclerosante, estenosis de papila y linfoma-B en un paciente con síndrome de inmunodeficiencia adquirida.

The case of a 31 year old man who had been intravenous drug abuser for years is reported. He was studied because of abdominal pain, jaundice, a weight loss of 10 kg, and the presence of a subclavicular mass. Biopsy of the mass demonstrated a high-grade B-cell non-Hodgkin's lymphoma, and the patient was classified in group IV-D of the human immunodeficiency virus infection because he had HIV serum antibodies and a reduced CD4/CD8 lymphocyte ratio. Although lymphoma had a good response to chemotherapy, persistent cholestasis led to liver and biliary evaluation. Sclerosing cholangitis and papillary stenosis were found. He has been followed for two years, without evidence of any secondary infectious disease associated to the acquired immunodeficiency syndrome.

[Sneddon syndrome: diagnostic value of antiphospholipid antibodies]. / Síndrome de Sneddon: valor diagnóstico de los anticuerpos antifosfolípido.

The association of livedo reticularis and cerebrovascular lesions is known as Sneddon's syndrome. It affects young adults and is more common in females. Repeated strokes lead these patients to residual deficits. Recently, Sneddon's syndrome has been described in a subset of patients with systemic lupus erythematous and primary antiphospholipid syndrome. We report two cases, one of them with antiphospholipid antibodies. Antiphospholipid antibodies do not seem to explain the events of Sneddon's Syndrome. Perhaps, different pathogenic mechanisms play role in the clinical expression of this syndrome.