The pharmacokinetics of heroin in patients with chronic pain

We measured blood concentrations of heroin and its active metabolites, 6-acetylmorphine and morphine, serially in 11 patients with chronic pain (9 of whom had cancer) after intravenous injection, intravenous infusion, intramuscular injection, and an oral dose of heroin hydrochloride. Parenteral heroin provided measureable blood levels of heroin, 6-acetylmorphine, and morphine. Blood levels of heroin and 6-acetylmorphine reached their maximal concentrations within minutes and were cleared rapidly. The mean half-life of heroin (+/- S.D.) after intravenous injection or infusion was only 3.0 +/- 1.3 minutes, and the mean clearance of heroin from the blood at apparent steady state was 30.8 +/- 2.1 ml per kilogram of body weight per minute. Morphine levels rose more gradually, and morphine was cleared much more slowly. Oral administration of heroin resulted in measurable blood levels of morphine but not of heroin or 6-acetylmorphine. The amount of circulating morphine provided by an oral dose of heroin was only 79 per cent of that available from an equal amount of morphine. We conclude that heroin is a pro-drug that serves to determine the distribution of its active metabolites. Parenteral heroin is rapidly converted to 6-acetylmorphine, which contributes to rapid pain relief. Oral heroin is converted to morphine and appears to be an inefficient means of providing morphine to the systemic circulation.

Advances in the management of cancer pain

The study of pain in the cancer patient offers a unique opportunity to use clinical observations to advance biologic knowledge. The cancer patient unfortunately represents the experimental model of pain. This group of heroic patients can help teach us the physiologic and psychologic differences between acute and chronic pain, the importance and evolution of psychologic factors, the difference between pain and suffering, the clinical pharmacology of analgesic drugs, and the behavioral mechanisms humans use to suppress pain. They are a rich resource of research potential which should not go untapped. The development of better methods of pain control will benefit all patients with pain. There is a pressing need to develop innovative approaches based on sound, scientific principles, and advances in research technology offer us the opportunity to understand the complex phenomenon of pain.

CT of the brachial plexus in patients with cancer

To assess the usefulness of CT, we reviewed 51 patients with clinically diagnosed brachial plexopathy who were seen between 1977 and 1981. The established etiology was metastatic tumor in 46 and radiation fibrosis in 5. CT was abnormal in 89% of tumor patients. Myelography, bone scan, and plain cervical spine radiographs were less useful. In four of five patients with radiation fibrosis, CT showed distortion of normal tissue planes without a discrete mass, but was not always distinguishable from tumor infiltration. CT of the brachial plexus provides the best two-dimensional view of tumor infiltration and detects bony changes earlier than standard radiographs. CT is a useful guide for surgical exploration of the brachial plexus, but does not differentiate tumor infiltration from radiation fibrosis.

Central nervous system excitatory effects of meperidine in cancer patients

The analgesic meperidine has been reported to produce signs of central nervous system excitation in human beings. To determine the relationship between signs and symptoms of central nervous system excitation and plasma levels of meperidine and normeperidine, we studied 67 patients receiving meperidine for the relief of postoperative or chronic pain. In 48 patients, excitatory effects ranging from mild nervousness to tremors, twitches, multifocal myoclonus, and seizures were directly correlated with accumulation of normeperidine in plasma. Evidence of compromised renal function occurred in only 14 of the 48 symptomatic patients, suggesting that renal dysfunction may contribute to but is not the sole factor in the accumulation of normeperidine or its relation to adverse neurological signs. In a second study we surveyed mood alterations in 47 patients receiving meperidine and 29 receiving other narcotic analgesics for postoperative pain. The repeated administration of meperidine was associated with adverse alterations in various elements of mood (e.g., apprehension, sadness, restlessness).

Current issues in the management of cancer pain: Memorial Sloan-Kettering Cancer Center

Recent attention to the management of cancer pain in the mass media (TV, books, newspapers) and the medical press provides ample evidence to suggest that many cancer patients are not receiving appropriate therapy for their pain. Since cancer therapy is often not curative, only palliative, specific attention to the management of pain in such patients is essential. However, the management of cancer pain requires a specific approach and expertise. Narcotic analgesics are the mainstay of therapy in the management of such patients, yet physicians lack sufficient knowledge of narcotic pharmacology to use these drugs appropriately. Recent controversy has arisen in 3 specific aspects of narcotic drug therapy: 1) the choice of a narcotic drug and its method of administration; 2) the development of tolerance, and 3) the risk of substance abuse, drug dependence, and addiction.

Brachial plexus lesions in patients with cancer: 100 cases

In patients with cancer, brachial plexus signs are usually caused by tumor infiltration or injury from radiation therapy (RT). We analyzed 100 cases of brachial plexopathy to determine which clinical criteria helped differentiate tumor from radiation injury. Seventy-eight patients had tumor (34 with previous RT), and 22 had radiation injury. Severe pain occurred in 80% of tumor patients but in only 19% of patients with radiation injury. The lower trunk (C7-8, T1) was involved in 72% of the tumors, and 32% also had epidural tumors. Seventy-eight percent of the radiation injuries affected the upper plexus (C5-6). Horner syndrome was more common in tumor, and lymphedema in radiation injury. The time from RT to onset of plexus symptoms, and the dose of RT, also differed. For symptoms within 1 year of RT, doses exceeding 6000 R were associated with radiation damage, whereas lower doses were associated with infiltration. Therefore, painless upper trunk lesions with lymphedema suggest radiation injury, and painful lower trunk lesions with Horner syndrome imply tumor infiltration.

Hypothesis: the pathogenesis of pseudotumor cerebri

In susceptible individuals, one of a variety of known or unknown precipitants affects the arachnoid villi so as to produce a large increase in CSF outflow resistance, Ra. This increase in Ra raises CSF pressure (CSFP), which rise provokes a redistribution of arteriovenous pressures across the cerebrovascular bed. The end result is a measurable increase in cerebral blood volume, compression of the ventricular system and compromise of the convexity subarachnoid space, which further increases CSF outflow resistance. Ultimately, a new steady state CSFP is attained.

Radiation-induced malignant and atypical peripheral nerve sheath tumors

The reported peripheral nerve complications of therapeutic irradiation in humans include brachial and lumbar plexus fibrosis and cranial and peripheral nerve atrophy. We have encountered 9 patients with malignant (7) and atypical (2) peripheral nerve tumors occurring in an irradiated site suggesting that such tumors represent another delayed effect of radiation treatment on peripheral nerve. The neoplasms appeared 4 to 41 years following radio-therapy, at a time when the patients (6 females and 3 males) were 16 to 70 years old and cured of their original tumors. Eight patients had received irradiation to treat malignant disease; the ninth had a benign condition. The sites of peripheral nerve tumor were the brachial plexus in 5, cervical plexus in 1, lumbar plexus in 2, and retroperitoneum in 1. Eight patients presented with painful masses, and in 6 of the 8 there was a progressive neurological deficit. Seven patients died with metastases within two years of diagnosis. In all instances the radio-therapy was within an acceptable radiation dosage, yet 3 patients developed local radiation-induced skin and bony abnormalities. In 3 patients there were either clinical signs or a family history of von Recklinghausen disease, but the malignant peripheral nerve sheath tumors developed only in the radiation port. Animal studies support the clinical observation that malignant peripheral nerve sheath tumors can occur as a delayed effect of irradiation. Other etiological mechanisms, including an increased risk of second primaries in cancer patients and a genetic predisposition to peripheral nerve tumors, may also play a role.

beta-Endorphin: analgesic and hormonal effects in humans

The pharmacokinetics and the hormonal, analgesic, and behavioral effects of several doses of human beta-endorphin were evaluated after intravenous administration to three patients and intracerebroventricular administration to one patient with pain caused by cancer. These effects were compared to the hormonal effects of intravenously administered morphine sulfate in two patients and an enkephalin analog in two baboons. The mean terminal half-life after intravenous administration of 5 or 10 mg of human beta-endorphin to three patients was 37 min; the mean volume of distribution was 178 ml/kg, and the metabolic clearance rate was 3.2 (ml/min)/kg. The half-life of beta-endorphin in cerebrospinal fluid after intracerebroventricular administration was 93 min, and the volume of distribution was 0.74 ml/kg. A rapid rise in plasma prolactin followed both intravenous and intracerebroventricular beta-endorphin. Intravenous administration did not affect plasma growth hormone, but intracerebroventricular administration suppressed plasma growth hormone. No significant change in plasma growth hormone was noted after intravenous administration of morphine to humans, but plasma growth hormone decreased in one baboon after administration of the enkephalin analog. beta-Endorphin-stimulated release of prolactin occurred at doses lower than those required to produce analgesic and other behavioral effects. When both hormonal and analgesic effects were observed (after 7.5 mg were given intracerebroventricularly), the onset of the hormonal response slightly preceded the analgesic and behavioral responses. These studies suggest that the hormonal effects of beta-endorphin are species dependent and are similar to those of morphine. Hormonal and analgesic effects of beta-endorphin appear to result from the activation of opiate receptors that differ in their locations and characteristics.

Normal CAT scans in craniopharyngioma

Three patients with symptoms of headache and vision loss had normal routine CAT scans, with and without injection of contrast medium, as their initial diagnostic procedure. Subsequent pneumoencephalography revealed large suprasellar masses, which at operation were found to be partially cystic craniopharyngiomas. The findings emphasize the existence of craniopharyngiomas that are isodense with brain and may not be detected on routine CAT scan. When a patient's clinical presentation suggests chiasmal or sellar abnormalities, the pneumoencephalogram remains the most accurate diagnostic procedure.

Does pseudotumor cerebri cause the empty sella syndrome?

Eight patients had both the "primary empty sella syndrome," diagnosed by the finding of an air-filled sella turcica at pneumoencephalography, and pseudotumor cerebri, diagnosed by the finding of an elevated cerebrospinal fluid pressure in the presence of normal ventricular size and position on pneumonencephalography. All eight patients were obese women, and six were hypertensive. Six complained of headaches and menstrual irregularities, and two were asymptomatic. Three had visual symptoms and four had papilledema at the time of examination. These two clinical disorders appear to be frequently related, and when they are related, visual field defects and visual loss are more likely to occur than when either entity appears alone. Chronically increased intracranial pressure from pseudotumor cerebri may produce an empty sella if the diaphragma sella is incompetent and the subarachnoid space herniates into the sella turcica.

White blood cell cultures in genetic studies on the human mucopolysaccharidoses

Cultures of white cells derived from peripheral blood of individuals homozygous and heterozygous for the inherited mucopolysaccharidoses revealed a distinct intracellular metachromatic staining with toluidine blue O. These short-term cultures circumvent the technical problems of skin fibroblast cultures and provide a simple screening procedure to detect the heterozygous state for the mucopolysaccharidoses, as well as offering an opportunity to study the heterozygous state of various inherited storage diseases.