Drug policy: striking the right balance

Drug policy should strike the right balance between reducing the harm done by psychoactive drugs and reducing the harm that results from strict legal prohibitions and their enforcement. It is concluded, from a cost-benefit analysis based on pharmacologic, toxicologic, sociologic, and historical facts, that radical steps to repeal the prohibitions on presently illicit drugs would be likely, on balance, to make matters worse rather than better. Specific recommendations are offered for ameliorating the dangers to users and to society that are posed by each addictive drug.

Do-Do abuse

Three cases of prolonged abuse of Do-Do tablets, an over-the-counter remedy for "coughs, wheezing and breathlessness", are reported. They have an amphetamine-like action and were used as easily obtained amphetamine substitutes, in one case to relieve social anxiety. Withdrawal symptoms similar to those following cessation of amphetamines occurred in two cases. Do-Do tablets are CNS stimulants and their abuse may be accounted for by the fact that they perhaps affect amine neurotransmitters.

Phenylpropanolamine and caffeine use among diet center clients

We surveyed phenylpropanolamine (PPA) use and overuse among 309 diet center clients. Fifty-one percent of all subjects surveyed reported using PPA drugs: 44 percent used cold medicines and 16 percent used diet aids. Twenty-two percent of diet aid users and 7 percent of cold medicine users reported that they deliberately used more than the dosage recommended to improve efficacy. Among diet aid users, 59 percent also regularly consumed caffeine. Despite package warnings, individuals who had been told by their doctors that they were hypertensive used PPA products as often as normotensive individuals. PPA, the fifth most frequently used drug in the USA, is contained in over-the-counter (OTC) diet aids as well as OTC and prescription cold medicines. Severe adverse drug reactions (ADRs) including hypertensive crisis, stroke and death have been attributed to PPA products. Clinical studies have shown that using greater than recommended doses of PPA and using PPA in combination with caffeine may increase the risk of ADRs. Overweight patients may be particularly at risk for ADRs to PPA because they are likely to be hypertensive and to use diet aids. We recommend informing diet center clients of the potential dangers of consuming PPA products, especially more than the recommended dose, in the presence of hypertension, and when other sympathomimetic drugs are being taken.

Effects of the acute administration of caffeine in patients with schizophrenia

Caffeine, 10 mg/kg, was administered to 13 schizophrenic patients in a double-blind placebo-controlled study of its behavioral effects. Some measures of psychopathology were significantly increased: Brief Psychiatric Rating Scale (BPRS) total, BPRS subscales thought disorder, unusual thought content, and euphoria-activation, and several individual BPRS items. Nurses' Bunney-Hamberg ratings of psychosis and mania, comparing the day before with the day after pharmacological challenge, increased significantly. Compared to placebo, caffeine also produced significant increases of diastolic blood pressure and cortisol. Thus, these findings indicate that caffeine increases arousal and has a psychotogenic effect when administered to schizophrenic patients. The possible roles of various neurotransmitters is discussed with special emphasis on caffeine's actions on dopaminergic and adenosinergic systems.

[Granulomatous processes in the lungs]

Findings of lung granulomas are not rare but their etiology may be embarrassing in autoptic and especially in bioptic material which is shown in two such cases: a 19-year old drug addict man practising intravenous administration of Alnagon pills and a 54-year old woman working with acrylonitrile fibres. Differential diagnosis of granulomas is discussed at large.

Malignant hyperthermia in the otolaryngologic patient: prospective anesthetic and surgical management of eight children

Malignant hyperthermia (MH) is a rare genetic myopathy whose hallmark is rise in body temperature. This hypermetabolic state is triggered by inhalational anesthetics and/or depolarizing muscle relaxants such as succinylcholine. Even the use of dantrolene may not be protective against the hypermetabolic crisis. Eight patients at risk for MH undergoing tonsillectomy, adenoidectomy, and/or myringotomy with ventilation tube insertion were anesthetized with nitrous oxide, barbiturates, opiates, tranquilizers, and nondepolarizing muscle relaxants without dantrolene and without complication. Cardiac monitoring and rectal temperatures were followed. In order to provide additional evidence, all eight patients had vastus lateralis muscle biopsies with subsequent caffeine-halothane contracture studies performed. The contracture study showed positive results in seven of eight patients studied, indicating MH-susceptible muscle. No anesthetic or operative complications were encountered. This study demonstrates that patients at risk of developing MH crisis can have otolaryngologic procedures performed relatively safely while undergoing appropriately selected anesthesia.

Contracture test and histologic and histochemical analyses of muscle biopsy specimens from horses with exertional rhabdomyolysis

Biopsy specimens of the cutaneous omobrachialis muscle were obtained from 10 horses with a problem of myositis from mild exercise. One horse had been evaluated previously and malignant hyperthermia-like contractures developed in its muscle biopsy specimen during the contracture test. In this study, the halothane-caffeine contracture test and histologic and histochemical evaluations were performed on muscle biopsy specimens. In the contracture test, no muscle biopsy specimen developed contracture in the presence of 2 or 4% halothane alone. The mean (+/- SEM) caffeine-specific concentration in the presence of halothane was 5.23 +/- 0.5 mM for 2% halothane, and 4.46 +/- 0.6 mM for 4% halothane. The caffeine-specific concentration values were not significantly different. Contracture response for any muscle specimen did not resemble contracture associated with malignant hyperthermia. The cutaneous omobrachialis muscle was composed of type-II fibers, with type-I fibers seldom seen. For 9 of the 10 horses, overall fiber morphology was normal; 1 horse had necrotic fibers. Of the 10 muscle specimens, 9 had fibers that had positive reaction for alkaline phosphatase activity; 3 muscle specimens contained ringed myofibers. Three horses of this study were administered general anesthesia; 2 were research horses, anesthetized with halothane and succinylcholine, and 1 was a clinical case given halothane anesthesia plus a non-depolarizing muscle relaxant. One research horse developed a malignant hyperthermia-like reaction to anesthesia, with severe rhabdomyolysis evident after anesthesia, and an episode of muscle cramping in its stall 2 days after anesthesia. The other 2 horses had unremarkable postanesthetic periods.

Safety of general anesthesia in patients previously tested negative for malignant hyperthermia susceptibility

Anesthetic management and outcome were examined in patients with negative in vitro contracture tests for malignant hyperthermia (MH). Contracture testing was performed in a standardized fashion using 3% halothane alone and incremental doses of caffeine alone. Medical records were examined for 54 anesthetic exposures in 42 MH(-) patients who had received anesthesia since their MH testing. Sixteen patients received anesthesia with known MH triggering agents on 23 occasions, all without incident. In six MH(-) patients with previous masseter muscle rigidity, no adverse reactions occurred in response to volatile anesthetic agents. Succinylcholine was avoided in these patients. Eleven MH(-) patients were managed as if MH-susceptible, although it was known that these patients had tested MH(-). Two of these patients also receive prophylactic iv dantrolene. These results suggest that "triggering" anesthetic agents may be safely administered to patients who test MH(-) by in vitro contracture testing. However, until the anesthetic experience of larger numbers of MH(-) patients is known, these results should be interpreted cautiously.

Use of quantitative liver function tests--caffeine clearance and galactose elimination capacity--after orthotopic liver transplantation

To establish the potential value of quantitative tests of liver function following orthotopic liver transplantation (OLT), a total of 100 determinations of caffeine clearance (CafCl) and galactose elimination capacity (GEC) were made in ten OLT recipients early in the post-operative course (days 2, 4, 6, 8 and 12) and later when clinically stable (3-12 months). Values were compared with a reference range in six normal volunteers in whom it was shown that the standard doses of caffeine (125 mg) and galactose (0.5 g per kg body weight) could be given together without interference. In orthotopic liver transplantation recipients initial GEC and CafCl measurements showed no correlation with peri-operative blood loss, donor ischaemia time, initial bile flow or survival. Throughout the early post-operative period, there were wide inter- and intra-individual variations in both CafCl (17-fold range from 0.16 to 2.7 ml.min-1.kg-1) and GEC (2.4-fold range from 5.1 to 12 mg.min-1.kg-1), but the only correlation of test values with standard liver function tests results was between GEC and gamma-glutamyltranspeptidase. However, GEC values fell by 19% during periods of acute rejection and there was an inverse correlation of GEC with white cell count probably related to sepsis.(ABSTRACT TRUNCATED AT 250 WORDS)

Caffeine and halothane contracture testing in swine using the recommendations of the North American Malignant Hyperthermia Group

Caffeine and halothane contracture testing is widely used to detect malignant hyperthermia (MH) susceptibility. The accuracy and reliability of the 3% halothane test and the incremental caffeine test, as recommended by the North American MH Group, were assessed in 11 swine (five MHS, six control). Nine swine were tested twice, 4-6 weeks apart. Accuracy of the in vitro diagnosis was also assessed by in vivo anesthetic challenge. Of all muscle bundles from MH-susceptible swine, 65% reacted positively to 3% halothane and 70% to 2 mM caffeine. Only 35% had a positive caffeine-specific concentration, and 25% developed an increase in baseline tension greater than or equal to 7% at 2 mM caffeine. However, when only the most positive response to 3% halothane or to 2 mM caffeine was used (a minimum of three fresh muscle strips is recommended), these two tests were highly sensitive and specific. In control swine one of 30 muscle bundles reacted positively to 3% halothane. A positive caffeine-specific concentration developed in one of 25 control muscle bundles exposed to caffeine. The variability in the results of these tests mandated that at least three muscle bundles be used for each test. Nonviable muscle bundles could not be relied upon to provide accurate results. In this porcine model, MH susceptibility could be detected by performing the Caffeine Halothane Contracture Test (CHCT) according to the guidelines of the North American MH Group. However, only the 3% halothane test and the response to 2 mM caffeine produced adequate diagnostic results in this breed of swine.

Clinical concentrations of verapamil affect the in vitro diagnosis of susceptibility to malignant hyperpyrexia

We examined the effects of verapamil on the in vitro caffeine and halothane tests for malignant hyperpyrexia (MH) susceptibility. Ten consecutive MH-susceptible patients were investigated according to the protocol of the European MH group. Additional tests were carried out in the presence of verapamil 10(-6) mol litre-1. In four of the 10 patients, the halothane contracture response following pretreatment with verapamil was classified as positive to halothane. In contrast, in nine of the 10 patients, contracture tests of muscle in the presence of verapamil were classified as negative to caffeine. It is advised that verapamil should be discontinued before performing a contracture test.

Isolation of a Ca2(+)-releasing factor from caffeine-treated skeletal muscle fibres and its effect on Ca2+ release from sarcoplasmic reticulum

In the presence of 2 mM caffeine, skeletal muscles of the frog exert small irregular oscillations of single sarcomeres. A factor, released from these oscillating muscles, was partially purified, and its activity was tested on skinned fibres and isolated vesicles of the sarcoplasmic reticulum (SR). Purification was achieved in three steps by gel filtration and reversed phase chromatography, and the active compound of the released material was shown probably to be a small peptide. In skinned fibres, the purified factor evoked repetitive contractions and subthreshold sarcomeric oscillations. In 'heavy' SR vesicles passively loaded with 45Ca2+, the factor induced a small but significant increase in the 45Ca2+ efflux rate. At the single channel level, the open probability of the SR Ca2+ release channel increased when the factor was added to the cytoplasmic side of the channel. The results reveal that the released factor potentiates Ca2+ release from the SR by increasing the open time of the Ca2+ release channel.

Aging is associated with increased Weber ratios for caffeine, but not for sucrose

To investigate whether age-associated changes in the human taste system are quality-specific, we compared young and elderly subjects' suprathreshold discrimination abilities for caffeine and sucrose. The method of constant stimuli was used to obtain just noticeable differences and Weber ratios. The elderly generated larger Weber ratios than did the young for both the medium and high concentrations of caffeine, but not for the low concentration. For example, a 74% increase in .005 M caffeine was required to obtain a perceptible difference for the elderly, whereas a 34% increase produced a perceptible difference for the young. The Weber ratios for sucrose did not differ for the two age groups. The results of this study indicate that age-associated changes in the taste system are quality-specific.

[The action of ketamine on muscle contractile behavior. In vitro studies on the musculature of subjects susceptible to malignant hyperthermia]

Since ketamine has been incriminated as triggering malignant hyperthermia (MH) [3, 9, 13, 14, 18], but has still been used uneventfully in MH susceptible patients, we performed an in vitro study to examine the safety of ketamine for use in human MH. METHODS. Muscle specimens of 20 patients who had muscle biopsies to diagnose MH were investigated. In every patient diagnostic contracture tests (2 halothane (Hal) and 2 caffeine (Caf) were done according to the protocol established by the European MH group (EMHG). In addition, one test unit for investigating the effect of stepwise increased bath-concentrations of ketamine (5, 10, 20, 60, 120, 240 and 960 mumol/l) and a further one serving as control (no drugs added to the bath) were used. Combined Hal (2 vol%) and Ket (960 mumol/l) tests were performed in 9 patients (4 MHS, 4 MHN, 1 MHEh). Changes in baseline contractures and mechanical twitch tension were evaluated. RESULTS. The diagnostic test showed MHS in 8, MHN in 8 and MHEh in 4 patients. Ketamine did not induce baseline contractures in any of the tests performed. Contractures induced by 2 vol% of halothane in 4 MHS muscles did not change significantly when ketamine was added to the bath (concentration 960 mumol/l). A significant, dose-related decrease in mechanical twitch tension occurred, when ketamine was added to the test. At the highest concentration (960 mumol) twitch tension was reduced by 55%. Twitch tension remained stable in untreated muscles. No significant differences were found between the specimens from MHS, MHN and MHE patients. This reduction in twitch tension was more pronounced in specimens exposed to both halothane (2 vol%) and ketamine (960 mumol/l), resulting in an average decrease of 71%. CONCLUSION. In accordance with Fletcher et al., our results indicate that ketamine - at least in vitro - does not trigger MH. In MHS muscles, ketamine does not augment halothane-induced baseline contractures. The ketamine-induced reduction of mechanical twitch tension in directly stimulated human muscles has not been described before. Analogous findings in frog sartorius muscles can be found in the literature. Whereas the effect of ketamine on indirectly stimulated muscle has been investigated by several authors, the underlying mechanism of ketamine-induced twitch suppression in directly stimulated muscles is not known. Inhibition of calcium release from or accelerated uptake into the sarcoplasmatic reticulum have been reported.

Maturation of AFMU excretion in infants

The maturation of the N-acetyltransferase-dependent AFMU production from caffeine was studied during infancy. The group of children (N = 14) consisted of 4 premature newborn infants and ten 1-19 month-old infants who received caffeine citrate solution for the treatment and prevention of apnea. Caffeine, AFMU, 1X and 9 other metabolites were measured in urine using HPLC. The AFMU/1X ratio did not vary significantly in this population with increasing age. In one of the infants serially studied, the AFMU/1X ratio increased dramatically between 6 and 12 months of age. This observation suggests that the maturation of N-acetyltransferase activity is not completed before 1 year of age implying that acetylator status cannot reliably be determined before that age. Patients studied before 1 year of age whose AFMU/1X ratio was below 0.4 may be either true slow acetylators or still immature fast acetylators.

[Elevation of the blood kynurenine level in caffeine-induced anxiety]

Concentration of neuroactive tryptophane--kynurenine metabolite was studied in healthy men volunteers in conditions of anxiety artificially elicited by caffeine. At peak of the alarm the level of the kynurenine significantly increased and came to norm after anxiety cessation. Possible causes of this increase are discussed. High correlation has been obtained between the kynurenine concentration and initial values of personal and reactive anxiety. The conclusion is made about the participation of the kynurenine in formation of personal and reactive anxiety in man.

The association between the neuroleptic malignant syndrome and malignant hyperthermia

The neuroleptic malignant syndrome (NMS) is an uncommon but dangerous complication of treatment with neuroleptic drugs. A primary defect in skeletal muscle has been suggested in view of similarities in the clinical presentations of NMS and anaesthetic-induced malignant hyperthermia (MH). The in vitro halothane-caffeine contracture tests are the most reliable method of identifying individuals susceptible to MH. The aim of this study was to define if a relationship exists between NMS and MH susceptibility. Hence, the in vitro halothane and caffeine contracture tests were performed on muscle tissue obtained from eight NMS, ten MH-susceptible and ten control patients. The results, which are expressed in accordance with the criteria of the European MH Group, defined the eight NMS subjects as MH non-susceptible. The response to halothane and caffeine exposure of skeletal muscle from NMS and control subjects was the same and significantly different from that of muscle from patients susceptible to MH. Furthermore, muscle from subjects in NMS and control group responded similarly to increasing concentrations of chlorpromazine. These results do not point towards an association between NMS and MH.

Malignant hyperthermia in humans--standardization of contracture testing protocol

Malignant hyperthermia (MH) diagnostic biopsy centers across North America have not previously been standardized in regard to protocols and specific muscles. Recent standardization criteria prompted this study of the vastus and rectus abdominis muscles. This study evaluated changes in contracture tension after electrical stimulation of 271 bundles taken from the vastus (n = 16) and rectus abdominus (n = 19) muscle biopsies of normal individuals when exposed to tissue baths in the absence of and in the presence of caffeine (0.5, 1.0, 2.0, 4.0, 8.0, and 32.0 mM) alone, halothane (1% or 3%) alone, or the combination of halothane (1%) plus caffeine (0.25, 0.5, 1.0, 2.0, 4.0, and 32.0). Caffeine threshold concentration was that concentration of caffeine that produced a 7% increase in tension. Caffeine specific concentration (CSC) and halothane caffeine specific concentration (HCSC) were those concentrations of caffeine alone or of halothane plus caffeine that produced a 1 g increase in tension. The concentration of caffeine alone that increased the contracture tension by 7% averaged 6.7 +/- 0.3 mM for vastus, significantly greater than 4.1 +/- 0.2 mM for the rectus muscle biopsies. Caffeine specific concentration was significantly greater for vastus muscle (7.7 +/- 0.7 mM) than it was for rectus muscle (4.9 +/- 0.4 mM). Three percent halothane alone showed contractures in 3/41 vastus (all less than 0.5 g) and 18/54 rectus muscle bundles (8 greater than 0.5 g). Mean HCSC was statistically significantly greater for vastus muscle (1.9 +/- 0.2 mM) than for rectus muscle (1.2 +/- 0.2 mM).(ABSTRACT TRUNCATED AT 250 WORDS)

[Behavioral study on an antitussive and expectorant, and of its constituents. II. Effects on ambulatory activity after repeated administration, and a modification of the methamphetamine sensitivity in mice]

Effects of repeated oral administration of a commercial preparation of antitussive and expectorant, BRON-W Solution (SS Pharmaceut., BRON; 10ml/kg), and of single and combination of dihydrocodeine (2HCOD; 10mg/kg), methylephedrine (MEPH; 20mg/kg), caffeine (CAF; 20.6mg/kg) and chloropheniramine (CPA; 4mg/kg) were investigated by means of ambulatory activity in mice. The drug doses tested were identical with those in BRON 10ml/kg. The drug administration was conducted 5 times at intervals of 3-4 days. Furthermore, 4 days after the final treatments, all mice were given methamphetamine 2 mg/kg s.c. In the single administration regimen of individual drugs, only CAF significantly increased the ambulatory activity. However, there was no significant change in the ambulation-increasing effect of CAF after the repeated administration. The other 3 drugs failed to elicit any marked change in the activity throughout the 5 times administration. Such the repeated administration of the individual drugs induced no significant change in the sensitivity to the ambulation-increasing effect of methamphetamine. BRON and BRON-corresponding combination of 4 drugs increased the ambulatory activity in the 1st administration, and the ambulation-increasing effect was progressively enhanced by the repeated administration of these preparations. On the other hand, although CAF-containing solutions significantly increased the ambulatory activity in the 1st administration, the proportions of the changes in the ambulatory activity during the repeated administration regimen were different from that observed after BRON. The combined administration of 2HCOD + MEPH + CPA failed to increase the ambulatory activity in the 1st administration, but significantly increased it in the 2nd and 3rd administration, then elicited again no significant increase in the activity in the 4th and 5th administration.(ABSTRACT TRUNCATED AT 250 WORDS)