A comparison of intramuscular and sublingual buprenorphine, intramuscular morphine and placebo as premedication

Buprenorphine premedication by two routes, 0.4 mg sublingual and 0.3 mg intramuscular was compared double-blind, double-dummy with intramuscular morphine 10 mg and placebo in 74 patients undergoing elective total hip replacement. Anxiety, depressive mood, sedation, vital signs and side-effects were measured before surgery. All patients then received a standardised general anaesthetic using a muscle relaxant and ventilation. The effects of the premedication on the anaesthetic were assessed by a scoring system. Intra- and postoperative blood gases, plasma cortisol and glucose were measured and the 1 hour postoperative pain intensity, side-effects and sedation were assessed. No differences between the premedications were seen on any of the pre-, intra- or postoperative measurements, suggesting that even with adequate measurement sensitivity it is difficult to distinguish opiate from placebo premedication.

Increased cortisol excretion in chronic pain

Urine samples were collected from 67 patients attending a Regional Pain Unit for treatment of chronic pain. Patients treated with steroids or with any signs or symptoms of Cushing's syndrome were excluded. The urine cortisol creatinine ratio was subsequently measured. Values for the urine cortisol/creatinine ratio were elevated in 31% of the patients, and grossly elevated in some. These patients could not be differentiated from those with normal ratios on the basis of pain or mood scores, cause of pain or drug therapy; they tended to have pain of shorter duration. Possible interpretations of these results are discussed.

Brain neuronal RNA metabolism during acute soman toxication: effects of antidotal pretreatments

Effects of various antidotal treatments on neuronal RNA contents and on soman induced RNA and acetylcholinesterase (AChE) depletion were monitored using quantitative cytochemical techniques. In rats only with antidotes, atropine depressed whereas pralidoxime (2-PAM) elevated RNA contents of both caudate and cerebrocortical (Layer V) neurons. Soman produced a virtually complete inhibition of AChE activity and a moderate decline in neuronal RNA contents. Atropine pretreatment partially restored neuronal RNA levels. Atropine + 2-PAM prophylaxis eventuated in a complete restoration of RNA levels but no reactivation of AChE. Addition of physostigmine to the atropine + 2-PAM treatment regimen resulted in appreciable AChE reactivation but reduced RNA levels. The overall data indicate that: (1) soman-induced neuronal RNA depletion can be completely reversed by antidotal pretreatments; (2) no precise relationship exists between the extents of antidote-induced restoration of RNA and AChE levels; and (3) 2-PAM exerts marked effects on the brain neuronal network which are unrelated to AChE reactivation. It is postulated that effects of soman and antidotes on neuronal RNA metabolism may signify alterations in acetylcholine (ACh) sensitivity and that pharmacologic manipulation of ACh responsiveness during organophosphate cholinesterase poisoning may be a mechanism for additional therapeutic intervention.

Comparison of flupirtine maleate and dihydrocodeine in patients following surgery

Flupirtine maleate 100 mg was compared with dihydrocodeine 60 mg when given by mouth to 50 women on the first 3 days following abdominal hysterectomy in a double-blind parallel-group trial. The analgesia produced was similar for both preparations, and the consumption of active drug was the same in both groups. The only significant differences in side-effects were an increased frequency of depression in patients receiving flupirtine and of sleepiness in those receiving dihydrocodeine.

Comparison of effects of intraoperative and postoperative methadone: acute tolerance to the postoperative dose?

The effects of methadone 10 mg administered in two different clinical contexts, at induction of anaesthesia and following operation, were studied in two groups of patients undergoing elective total hip replacement. The intraoperative group received methadone 10 mg i.v. at induction of anaesthesia as part of a balanced anaesthetic technique. The postoperative group received methadone 10 mg i.v. following operation, extradural bupivacaine being used for the operative period. A demand analgesia system delivering methadone i.v. was used after operation in both groups. Arterial blood-gas tensions, cortisol and glucose concentrations, analgesic effects and plasma methadone concentrations were compared in the two groups. The only major difference between the two groups was in analgesic requirement. At the time of connection to the demand system the two groups had the same plasma methadone concentrations. Subsequently, the postoperative group had a significantly greater analgesic requirement which resulted in significantly greater plasma methadone concentrations the following morning. Thus, the administration of methadone following operation appeared to exert less analgesic effect than the same dose given during operation. The reasons for this are discussed.

Chlorpropamide-alcohol flushing and plasma chlorpropamide concentrations in diabetic patients on maintenance chlorpropamide therapy

Forty-three diabetic patients on maintenance chlorpropamide (100-750 mg daily) drank 0.2 ml/kg 90% ethanol after equilibration in a room controlled at 20 degrees C. Twenty-five patients had already noted marked alcohol flushing since starting chlorpropamide therapy (group A), while 13 had not observed this (group B). The remainder were teetotal or unsure of their reaction. Cheek temperature rise correlated with plasma chlorpropamide concentration (r = 0.6, p less than 0.001) in all patients and was inversely related to basal cheek temperature (r = -0.35, p less than 0.02). Plasma chlorpropamide correlated with daily chlorpropamide dose (r = 0.8, p less than 0.001) but not with basal cheek temperature. The correlation between chlorpropamide level and cheek temperature rise was strengthened on analysis of group A alone (r = 0.7, p less than 0.001) and absent in group B (r = 0.2, p greater than 0.3) who tended to have lower chlorpropamide levels and cheek temperature rise than group A.

Current status of the field: contrasting perspectives. A medical clinician's perspective

Because alcoholism is viewed and treated as a bad habit, almost all treatment approaches are covertly behavioral. Behavior therapy as a specific and overt approach to alcoholism is widely written and talked about. Nevertheless, it is not the major approach utilized in the majority of treatment programs. This is a result of a trend toward deprofessionalization in the field manifested by a reluctance to accept ideas not compatible with accepted with accepted dogma, a reluctance of professionals dynamically oriented to accept behavioral approaches, and a lack of belief in the efficacy of behavior therapy. It is vital to keep the field open to new ideas and facts; if we do, behavior therapy has a bright future in the treatment of alcoholism.

Acute i.v. Methadone Kinetics in Man: relationship to chronic studies

Twenty-six patients were given methadone 10 mg i.v. to obtain acute human kinetics. Plasma methadone concentrations from separate 3- and 6-h studies were measured by radioimmunoassay. Kinetic parameters derived from triexponential NONLIN analysis showed that T1/2 alpha and T1/2 beta were 2 and 30 min respectively; no reliable estimate for T1/2 gamma could be obtained. The clearance was estimated as 149 /+- 62 and 163 /+- 49 ml min-1 in the 3- and 6-h studies respectively. These values are compared with those published for chronic administration. The difficulties in determining accurate terminal half-life and clearance values from short duration studies are discussed; these difficulties are accentuated by the long terminal half-life of methadone. Appropriate estimates of clearance may be derived from an acute short duration study provided that the average of triexponential fits to individual patients data is used, even when data extend from only 3h. As might be anticipated, no analysis produced appropriate terminal half-life values for this drug.

Dural permeability to narcotics: in vitro determination and application to extradural administration

The permeability of cranial and lumbar dura to various substances including a number of narcotic analgesics was measured in vitro. Preliminary data On human postmortem material is reported. Permeability had a linear relation to the inverse of the square root of molecular weight. This is the expected relationship for a diffusion process dependent upon molecular weight. The differential mass selectivity coefficients for lumbar and cranial dura were calculated; they were similar at 0.8 and 0.9. This was greater than for diffusion in simple liquids, but much less than that for biological lipid membranes. This suggests that the low rates of diffusion are a property of the thickness of the dura rather than any inherent impermeability. A simple model for the dural transfer of drugs is described, and applied to narcotics. Its purposes were to suggest: the factors involved in the dural transfer of drugs; the physicochemical properties of drugs relevant to their dural transfer; worthwhile measurements in future studies. The model indicates that drug molecular weight and rate of absorption are important determinants of the efficiency of dural transfer. Low molecular weight and slow absorption produce high dural transfers. When applied to narcotics, these factors could produce a difference of up to an order of magnitude in the amount transferred directly across the dura.

Some patients don't need analgesics after surgery

Postoperative analgesic requirements of 410 patients undergoing elective orthopaedic limb surgery were studied. Premedication and anaesthetic were standardized with no narcotic. Twenty-three patients required no analgesic at all during their hospital stay. The importance of acknowledging the existence of this group of patients is discussed. The distribution of time to first analgesic requirement for the other patients was obtained. The importance of knowing the distribution for particular operative procedures and the effect of analgesic interventions such as premedication is discussed.

Some Patients Don't Need Analgesics after Surgery

Postoperative analgesic requirements of 410 patients undergoing elective orthopaedic limb surgery were studied. Premedication and anaesthetic were standardized with no narcotic. Twenty-three patients required no analgesic at all during their hospital stay. The importance of acknowledging the existence of this group of patients is discussed. The distribution of time to first analgesic requirement for the other patients was obtained. The importance of knowing the distribution for particular operative procedures and the effect of analgesic interventions such as premedication is discussed.

Sublingual buprenorphine used postoperatively: ten hour plasma drug concentration analysis

1 A 10 h study of plasma drug concentrations of the opiate buprenorphine after use was designed because a previous 3 h study had shown that peak plasma drug concentrations in some patients had not occurred by 3 h after the sublingual dose. 2 Fifteen postoperative patients were studied: at 3 h after a 0.3 mg intravenous dose five patients received a sublingual preparation of 0.4 mg of buprenorphine, five 0.8 mg of buprenorphine and five placebo. Plasma drug concentrations of buprenorphine were measured by specific radioimmuno-assay. 3 Plasma drug concentrations after sublingual buprenorphine were significantly higher than those in the placebo group by 1 h. They remained significantly higher over the succeeding nine hours. The mean time to peak plasma drug concentration was about 200 min in both the 0.4 mg and 0.8 mg groups (range 90-360 min). The plasma drug concentrations in the 0.8 mg group were approximately twice those in the 0.4 mg group; the ratio of the relative systemic availabilities was similarly 1.8:1. The absolute systemic availability was estimated at about 55% for both groups. Uptake of buprenorphine from the sublingual site was essentially complete by 5 h after the dose was given. 4 The implications for the timing of sublingual doses in clinical use are discussed.

Phaeohyphomycosis of brain: granulomatous encephalitis caused by Drechslera spicifera

Drechslera spicifera is a dematiaceous fungus which occurs widely in nature but only rarely has been implicated in animal and human infections. Previous infections have occurred in superficial and subcutaneous sites or were encountered in immunologically compromised hosts. This report documents a case of granulomatous encephalitis due to Drechslera spicifera in an immunologically competent woman with no known underlying disease, from whom the fungus was isolated. Animal pathogenicity studies in mice reproduced the histopathologic features, and the fungus was reisolated from the animals.

Single-dose comparison of buprenorphine 0.3 and 0.6 mg i.v. given after operation: clinical effects and plasma concentration

The plasma concentrations and clinical effects of a single i.v. dose of buprenorphine 0.3 or 0.6 mg were studied in patients recovering from surgery. Analgesic and hormonal effects were greater with the greater dose without a parallel increase in respiratory depression. A comparison with previous work suggests that increased efficacy results either from the use of the larger dose or equivalently if the first required postoperative dose of 0.3 mg has been preceded by a similar loading dose.

An oral buprenorphine and paracetamol combination compared with paracetamol alone: a single dose double-blind postoperative study

1 An oral combination of buprenorphine and paracetamol was compared with paracetamol alone in a single dose, double-blind postoperative study. One hundred and twenty patients undergoing elective minor orthopaedic operations were allocated to four groups of 30 patients. The four treatments were 1,1.5 or 2 mg of buprenorphine with paracetamol 1,000 mg or paracetamol 1,000 mg alone. 2 There were no significant differences between the groups in analgesia measured by the observer over the 6 h period of direct observations. The oral opiate produced a significant increase in duration of analgesia beyond the 6 h study period. A significant increase in side-effects was seen only at the highest buprenorphine dose compared with paracetamol. 3 The problems of trial design for analgesic combinations are considered. Drug mixtures create additional complexities which decrease the certainty of the conclusion that no real benefits result from such mixtures.

Ammonium and methylammonium transport by the nitrogen-fixing bacterium Azotobacter vinelandii

Azotobacter vinelandii, grown with NH4+ as nitrogen source, was shown to possess an active transport system which can take up NH4+ against a concentration gradient of 58-fold. The properties of the NH4+ uptake system were investigated with the NH4+ analog CH3NH3+. The use of this analog was justified on the basis of the conclusion that the uptake of NH4+ and CH3NH3 involves a common binding site, as shown by the competitive inhibition of CH3NH3+ uptake by NH4+ (Ki approximately 3 microM). A Lineweaver-Burk plot for CH3NH3+ uptake revealed a biphasic curve, suggesting the existence of two CH3NH3+ (NH4+) uptake systems with apparent Km's for CH3NH3+ equal to 61 microM and 661 microM. The uptake of CH3NH3+ was inhibited by arsenate, as well as by cyanide or carbonyl cyanide-m-chlorophenyl hydrazone, indicating that phosphate bond energy is required.

Sublingual buprenorphine used postoperatively: clinical observations and preliminary pharmacokinetic analysis

1 Buprenorphine is a long-acting opiate analgesic. This study was designed to investigate the pharmacokinetics of this drug when given by the sublingual route to ten postoperative patients. Plasma levels of buprenorphine were measured by a specific radioimmunoassay. 2 Plasma levels of the drug following sublingual administration of 0.4 mg showed an apparent delay in absorption and then rose slowly to reach low but significant levels by 3 h. There was considerable variation in the time at which peak levels were achieved. The average systemic availability of the drug by this route was estimated to be 30% by 3 h. 3 Analgesic efficacy and duration of sublingual buprenorphine were assessed using demand analgesia. The analgesia was of about 9 h duration, similar to that achieved by parenteral administration of 0.3 mg of the drug to an equivalent group of patients. The sublingual dose caused a significant fall in the postoperatively elevated group of patients. The sublingual dose caused a significant fall in the postoperatively elevated plasma glucose, and prevented any further rise in plasma cortisol. 4 Reasons for the efficacy of the sublingual route are discussed and it is suggested that this route may be particularly appropriate for highly lipophilic drugs like buprenorphine.

Sex and surgical stress

The endocrine and metabolic response to anaesthesia and surgery was studied in 12 men and eight women undergoing elective total hip replacement using buprenorphine as the intra- and postoperative analgesic. Plasma glucose, cortisol and prolactin were measured, and the results obtained for men and women compared. Statistically significant difference between men and women were found for prolactin during and after operation, and also for cortisol postoperatively. Men, but not women, demonstrated a significant fall in plasma cortisol following a dose of buprenorphine after operation. These results are discussed in relation to known procedures for ablating the stress response and to the neuroendocrine effects of opiate agonists and partial agonists.

Cimetidine and parenteral nutrition

A number of patients receiving continuous intravenous infusions of hyperalimentation solutions require cimetidine (CT) for treatment of gastric hypersecretory conditions. Four patients were selected to receive a CT-hyperalimentation mixture and serial blood sampling for CT concentrations. Rates of infusion of CT ranged from 38 to 56.3 mg/hr. Average serum concentrations (C88) of CT at steady state ranged from 0.6 to 1.0 microgram/ml. This concentration range is near levels reported in patients receiving long-term oral CT and is lower than levels reported to be associated with central nervous system toxicity. No evidence of renal toxicity was noted. Pharmacokinetic parameters were comparable to previous reports in the literature. This initial investigation reveals that continuous intravenous infusion of CT in hyperalimentation solutions appears to be a safe mode of drug administration. More definitive studies are needed to assess efficacy.

Clinical effects of buprenorphine during and after operation

The analgesic, respiratory and hormonal effects of two doses of buprenorphine were studied during and after operation in 20 patients undergoing total hip replacement. The drug provided analgesia of long duration. The analesic and hormonal effects of the drug were greater after i.m. than after i.v. administration. The postoperative analgesic requirement of women was less than that of men. The pharmacodynamic differences shown between the sexes and between the two routes of administration are discussed in relation to the pharmacokinetics of the drug.

The radioimmunoassay of buprenorphine

Antisera to buprenorphine were obtained in rabbits immunised with 3-0-carboxymethylbuprenorphine and N-hemisuccinyl-norbuprenorphine conjugated to bovine serum albumin. Using the latter antiserum and tritium labelled buprenorphine a radioimmunoassay have good accuracy and precision was developed for concentrations as low as 50 picograms in 1 ml of plasma. The N-hemisuccinyl antiserum crossreacted with norbuprenorphine, and the 3-0-glucuronide conjugate with the 3-0-carboxymethyl antiserum. Cross-reactivity of both antisera to other pharmacologically related compounds was negligible. The assay was employed to determine plasma buprenorphine concentration following its parenteral administration to dog and man.

Detection of unrecognised nocturnal hypoglycaemia in insulin-treated diabetics

Cortisol to creatinine ratios in overnight urine samples, urinary glucose excretion, and plasma glucose concentrations were determined in 43 diabetic inpatients. All initially had normal cortisol to creatinine ratios (less than 55 x 10(-6)) and were initially treated by increasing their long-acting insulin component. Nine patients in whom this ratio became raised then had their long-acting insulin component reduced until their fasting plasma glucose concentration was 4-7 mol/l (72-126 mg/100 ml). The 34 patients who had never had a raised ratio were treated by increasing their long-acting insulin component until their fasting plasma glucose concentration was in the range 4-7 mmol/l. All the raised cortisol to creatinine ratios were clearly separate from the other values. A mean reduction in total insulin dose of 23% and in long-acting insulin dose of 53% was achieved, abolishing presumptive nocturnal hypoglycaemia by reducing the ratio to normal and dramatically improving diabetic control. Although there was no definite evidence that the patients who had raised cortisol to creatinine ratios had suffered from nocturnal hypoglycemia, these results strongly support the view that a raised ratio indicates an otherwise unrecognised episode of this condition.

Naloxone: underdosage after narcotic poisoning

A case of propoxyphene hydrochloride (Darvon) poisoning was unresponsive to therapeutic doses of naloxone hydrochloride in a 2 1/2-year-old girl. Following prolonged coma and artificial ventilation for three hours, the patient responded immediately to the intravenous administration of 2 mg of naloxone hydrochloride, which is 20 times the manufacturer's recommended dosage. Naloxone is the agent of choice in reversing the effects of narcotics and synthetic opiate derivatives, such as propoxyphene and pentazocine. The manufacturer's present recommended dosage may not be sufficient to reverse the effects of large narcotic ingestions. We therefore recommend that if there is no response within two minutes of the initial 0.01 mg/kg dosage of naloxone hydrochloride, a second dose 0.1 mg/kg (ten times the manufacturer's suggested dose) be given.

Diurnal changes in plasma lipoproteins in normal subjects and diabetics

Significant diurnal variations in levels of total plasma cholesterol, HDL cholesterol and LDL cholesterol were found in the majority of 12 normals, 13 maturity onset and 14 insulin requiring diabetics. The variations in total cholesterol and its lipoprotein subfraction were more marked in diabetics. These variations were not correlated in either diabetic group with glucose control as assessed by the level of glycosylated haemoglobin. The significance of the diurnal changes in total plasma cholesterol and the lipoprotein subfractions in relation to arteriovascular disease is discussed.

Computerized tomography in central pontine myelinolysis

We describe an autopsy-proven case of central pontine myelinolysis (CPM) with premortem computerized tomographic (CT) visualization of the lesion on two scans, performed with an interval of 2 weeks. This case demonstrates the capability of CT to support the clinical diagnosis of central pontine myelinolysis. Identification of the condition should facilitate prompt initiation of aggressive supportive care.

Hyperlipidaemia following renal transplantation. A study of the prevalence, 'natural history' and dietary treatment

In a study of 70 renal transplant patients, the prevalence of hyperlipidaemia eight to 28 months following transplantation was found to be 59 per cent. High density lipoprotein (HDL) cholesterol levels were normal but low-density-lipoprotein (LDL) cholesterol levels were significantly elevated compared with controls. Lipid levels, measured before and sequentially after transplantation for 22 months in 10 patients were elevated over the first six to 10 months. Thereafter the lipid values returned to normal in most patients. This change coincided with the attainment of maintenance steroid dosage (usually prednisolone 10 mg. daily; mean 12.5 mg). A diet designed to decrease cholesterol and increase polyunsaturated fat intake, resulted in a significant reduction of serum cholesterol levels but not of triglyceride values over a four week period. The results suggest that the hyperlipidaemia in the initial months after transplantation may well be related to the high dose steroid therapy during this period, and the levels of lipid return to normal once low dose maintenance therapy is attained. Lipid profiles and levels in the first eight to 12 months are variable and should not form the basis for therapy or assessment. Dietary modification alone is unlikely to be an effective form of treatment of severe hyperlipidaemia in these patients.

Improved glucose control in maturity-onset diabetes treated with high-carbohydrate-modified fat diet

Fourteen patients with established maturity-onset diabetes were treated as outpatients with a high-carbohydrate-(about 60% of total daily energy requirements)-modified fat diet (ratio of polyunsaturated fatty acids to other fatty acids greater than or equal to 1:1) for six weeks. Commercially available and acceptable cereal foods and tuberous vegetables high in both digestible and non-digestible carbohydrates were used. Simple sugars were restricted. Compared with their usual, low-carbohydrate diabetic diet this diet resulted in a fall in basal plasma glucose concentration (average of values measured at 0300, 0500, and 0700), mean preprandial plasma glucose concentration (average of values measured at 0800, 1230, and 1730), and percentage of glycosylated haemoglobin. Modifying dietary fat also decreased the fasting plasma cholesterol concentration. The findings suggest that it is no longer justifiable to prescribe a low-carbohydrate diet for maturity-onset diabetes.

High-density lipoprotein, lipid, and carbohydrate metabolism during increasing fitness

Eleven unfit bank executives in sedentary employment exercised daily for 10 weeks according to the Canadian Air-Force 5BX Exercise Programme. Over this period no changes were observed in the glucose or insulin responses to a standard breakfast or to intravenous glucose, or in the glucose response to intravenous insulin. There was a significant reduction in high-density-lipoprotein cholesterol, but total plasma triglyceride and cholesterol levels were unaffected by exercise.