Arousal of ethanol-intoxicated comatose patients with naloxone

Disposition of Ethanol and its Effect on Rectal Temperature in Morphine-dependent, Morphine-abstinent and Morphine-naive Rats

Rats were treated chronically with twice daily injections of morphine hydrochloride in gradually increasing doses from 20 to 200 mg/kg for 22 consecutive days. Rats in a control group were injected with 0.9% NaCl. At 1 hour after the last injection of morphine (dependent state) and at 3 and 16 days after abrupt withdrawal (abstinent state) the animals were injected intraperitoneally with 2.0 g/kg ethanol. Blood ethanol concentrations (tail blood) and rectal temperatures were determined at 30-60 min. intervals for up to 7 hours. The absorption of ethanol was slower in rats treated with morphine and the time taken to reach the end of the blood concentration curve was increased. This implies a slower turnover of ethanol in morphine-dependent and abstinent rats. At 16 days after withdrawal, the blood ethanol profiles were the same as in control rats not exposed to morphine. Injection of morphine (200 mg/kg) intolerant animals caused a pronounced hyperthermia which lasted for about 4 hours. Ethanol treatment rapidly counteracted the rise in body temperature. Morphine abstinent rats showed a hypothermic response to ethanol. The altered disposition of ethanol in acute withdrawal may result from physiological disturbances such as impaired fluid balance, dehydration, altered peripheral blood flow and poor nutritional status. There was no evidence for a faster rate of ethanol metabolism in the hypermetabolic state associated with morphine tolerance and dependence.

Pharmacological treatment of alcoholism

1. Pharmacological treatments are effective as part of a treatment plan that includes substantial education, psychological therapy and social support. This paper reviews recent literature on animal models of and treatment for alcohol abuse under seven categories: agents to block craving or reduce alcohol intake, agents to induce aversion to alcohol, agents to treat acute alcohol withdrawal, agents to treat protracted alcohol withdrawal, agents to diminish drinking by treating associated psychiatric pathology, agents to decrease drinking by treating associated drug abuse, and agents to induce sobriety in intoxicated individuals. 2. The benzodiazepines provide safe and effective treatment for detoxification, although current research focuses on finding drugs with a smaller likelihood of dependence. As yet, there are no drugs that effectively reverse the intoxicating effects of alcohol. 3. Currently, only two major groups of drugs that are relatively safe have shown any effect at reducing alcohol consumption: aversives such as disulfiram, and opioid antagonists such as naltrexone. 4. Finally, it is important to customize therapy for each patient rather than putting everyone through a standard treatment plan, especially in regards to the use of antidepressant or antipsychotic medications. Tailoring the program to the patient's needs dramatically improves the outcome of therapy and reduces the risk of adverse effects.

Integration of pharmacotherapies in the existing programs for the treatment of alcoholics: an international perspective

This review examines current therapies of alcoholism and addresses the difficulties encountered in evaluating the result of integrating pharmaco- and psychosocial treatment of alcoholics. A variety of treatment modalities and goals, and factors influencing admission of alcoholics, exist in different countries creating problems of comparability. Recognition of alcoholism as a separate entity from associated psychiatric co-morbidity coupled with the introduction of specific pharmacotherapies represent a major advance in the treatment of alcoholism. Combining psychosocial and pharmacological treatments appears to be the most effective approach in the treatment of alcoholics. In the future, rational therapy with appropriate choice of treatment strategies will decrease the necessity for hospital treatment of alcoholic patients.

A comprehensive review of naloxone for the emergency physician

Naloxone has enjoyed long-standing success as a safe and effective opioid antagonist and has been invaluable in defining the role of endogenous opioid pathways in the response to pathological states such as sepsis and hypovolemia. We look forward to exciting research to further elucidate these pathways and to improve outcome by modulating the patient's physiological response to these stresses.

Pharmacotherapies for alcoholism: promising agents and clinical issues

The past 10 years have witnessed important advances in research on pharmacotherapy for alcoholism. Promising drugs are discussed under six headings: agents to treat alcohol withdrawal; anticraving agents; agents that make drinking an aversive experience; agents to alleviate concomitant psychiatric problems; agents to treat concurrent drug abuse; and amethystic ("sobering-up") agents. Research on the drug classes is summarized and clinical issues surrounding specific agents and alcoholism pharmacotherapy in general are discussed. Finally, long-range therapeutic implications of recent findings on the actions of alcohol on basic mechanisms of the brain are offered.

Acute ethanol poisoning and the ethanol withdrawal syndrome

Ethanol, a highly lipid-soluble compound, appears to exert its effects through interactions with the cell membrane. Cell membrane alterations indirectly affect the functioning of membrane-associated proteins, which function as channels, carriers, enzymes and receptors. For example, studies suggest that ethanol exerts an effect upon the gamma-aminobutyric acid (GABA)-benzodiazepine-chloride ionophore receptor complex, thereby accounting for the biochemical and clinical similarities between ethanol, benzodiazepines and barbiturates. The patient with acute ethanol poisoning may present with symptoms ranging from slurred speech, ataxia and incoordination to coma, potentially resulting in respiratory depression and death. At blood alcohol concentrations of greater than 250 mg% (250 mg% = 250 mg/dl = 2.5 g/L = 0.250%), the patient is usually at risk of coma. Children and alcohol-naive adults may experience severe toxicity at blood alcohol concentrations less than 100 mg%, whereas alcoholics may demonstrate significant impairment only at concentrations greater than 300 mg%. Upon presentation of a patient suspected of acute ethanol poisoning, cardiovascular and respiratory stabilisation should be assured. Thiamine (vitamin B1) and then dextrose should be administered, and the blood alcohol concentration measured. Subsequent to stabilisation, alternative aetiologies for the signs and symptoms observed should be considered. There are presently no agents available for clinical use that will reverse the acute effects of ethanol. Treatment consists of supportive care and close observation until the blood alcohol concentration decreases to a non-toxic level. In the non-dependent adult, ethanol is metabolised at the rate of approximately 15 mg%/hour. Haemodialysis may be considered in cases of a severely ill child or comatose adult. Follow-up may include referral for counselling for alcohol abuse, suicide attempts, or parental neglect (in children). The ethanol withdrawal syndrome may be observed in the ethanol-dependent patient within 8 hours of the last drink, with blood alcohol concentrations in excess of 200 mg%. Symptoms consist of tremor, nausea and vomiting, increased blood pressure and heart rate, paroxysmal sweats, depression, and anxiety. Alterations in the GABA-benzodiazepine-chloride receptor complex, noradrenergic overactivity, and hypothalamic-pituitary-adrenal axis stimulation are suggested explanations for withdrawal symptomatology.(ABSTRACT TRUNCATED AT 400 WORDS)

Naloxone, ethanol, and the chlorpropamide alcohol flush

The effects of ethanol and subsequent administration of intravenous naloxone were studied in double-blind, placebo-controlled fashion with a group of six male chlorpropamide alcohol flushers (CPAF) and a group of 13 nonflushing males. The effect of ethanol intoxication on fine motor control was measured by a typing test. When sober, the two groups performed in comparable fashion. When intoxicated, the CPAF group displayed significantly greater impairment than the nonflushing group as measured by typing errors committed in 3 min (CPAF: 55.4 +/- 10.1 errors, n = 12; vs. nonflushing: 15.6 +/- 2.3, n = 32; p = 0.0000015 by Student's unpaired t test). Chlorpropamide alcohol flushers appeared to be more sensitive to ethanol. Naloxone reversed this effect for individuals in the CPAF group (saline treatment: 51.0 +/- 11.7 errors per minute; vs. naloxone treatment: 23.7 +/- 4.2; p = 0.034 by Student's paired t test, n = 6). Naloxone had no effect in the nonflushing group. Unlike the normal, nonflushing group, the CPAF group demonstrated an increased sensitivity to ethanol that was partially antagonized by naloxone.

Physical assessment and differential diagnosis of the poisoned patient

The rapid diagnosis and immediate intervention required in patients with serious drug overdose or poisoning makes toxicological screening of limited value to the emergency department physician. Instead, a careful clinical evaluation using the history, physical examination, and the more readily available laboratory tests may allow a tentative diagnosis and the initiation of life-saving treatment. Laboratory tests should include serum osmolality, electrolytes, glucose, BUN and an estimation of the anion and osmolar gaps. The ECG can also provide useful information. Clinical findings of important include altered blood pressure, pulse, respiration and body temperature, the presence of coma, agitation, delirium or psychosis, and muscular weakness. An ophthalmological examination is also of importance in the acutely poisoned patient. Oral burns or dysphagia may occur following ingestion of any strongly reactive substance, but the absence of oral burns does not preclude the possibility of oesophageal or stomach injury. Odours and skin colour may also contribute to the diagnosis. Comprehensive toxicology screening may not be immediately available, or may be inaccurate, thus adding little to the information obtained during the initial evaluation of the poisoned patient.

Determination of beta-endorphin in alcoholic patients in the acute stage of intoxication: relation with naloxone therapy

beta-Endorphin was measured in the plasma of control subjects and 12 chronic alcoholics in the acute stage of ethanol intoxication. Naloxone was administered and the level of beta-endorphin was compared before and after treatment. The increased level of beta-endorphin in the intoxicated subjects supports the presence of ethanol interactions with the opioid system, since pituitary secretion does not seem to be involved. Furthermore, the coexistence of high levels of beta-endorphin and an effective naloxone response suggest a possible link between the two.

Neonatal monosodium glutamate lesions alter neurosensitivity to ethanol in adult mice

A number of studies have indicated a relationship between brain peptide activity and sensitivity to the behavioral effects of ethanol. Specifically, it has been suggested that ethanol effects are mediated by changes in the endogenous opioid peptides derived from the proopiomelanocortin (POMC) precursor. Most cell bodies containing brain POMC-derived peptides are found in the arcuate nucleus of the hypothalamus. Neonatal administration of monosodium glutamate (MSG) has been reported to destroy cell bodies of the arcuate nucleus. We treated WSC strain mice on postnatal Day 4 with a single SC injection of 4 mg/g MSG or saline. When adult, MSG and control mice were challenged with an IP injection of ethanol and its effect on body temperature, open field activity, or duration of loss of righting reflex was assessed. Blood ethanol concentration (BEC) was measured and the hypothalamic content of beta-endorphin like immunoreactivity (beta-EP) was determined by radioimmunoassay. beta-EP was markedly reduced in both females and males by MSG treatment. MSG-treated animals of both sexes showed significantly less ethanol-induced hypothermia than controls. BEC was higher in MSG-treated animals of both sexes than in controls, so the differences were not due to ethanol pharmacokinetics. beta-EP was generally lower in males. Duration of righting reflex was prolonged in MSG treated animals, and the reduction in open field activity was potentiated. These latter effects may be in part attributable to the higher BECs achieved in lesioned animals. These data suggest that beta-EP cell bodies in the arcuate nucleus of the hypothalamus mediate neurosensitivity to some effects of ethanol in mice, but further experiments will be necessary to implicate beta-EP specifically.

Naloxone in shock and toxic coma

In summary, naloxone has proved to be effective and safe during its years of use for narcotic antagonism. Its usefulness in non-narcotic coma and shock remains controversial, although some encouraging but inconclusive evidence exists. The final answer lies on the horizon of medicine; it awaits further delineation of the role of endogenous opioids in health and disease and clear statistical verification of naloxone's efficacy in such disease states.

Endogenous opiates: 1982

This article is the fifth installment in an annual series of reviews of successive year's research dealing with the endogenous opiate peptides. Due to the continuing massive increase in the number of studies in this field, it has become impossible to continue comprehensive reviews of all aspects of this work. As a result we have decided that beginning this year the coverage will be abbreviated to emphasize non-analgesic and behavioral work. The specific areas discussed include stress, tolerance and dependence, consummatory responses, alcohol consumption, schizophrenia and emotional disorders, learning and memory, cardiovascular responses, respiratory effects, thermoregulatory effects, neurological deficits and other disorders, activity, and other, miscellaneous behaviors. As in previous years, we have attempted a relatively comprehensive review of the subjects covered only for the previous year and have not made an attempt to evaluate their contributions relative to those of past years.