Spanish version of the 49-item short form of the Addiction Research Center Inventory (ARCI)

The Spanish version of the 49-item short form of the Addiction Research Center Inventory (ARCI) was assessed in simulated drug conditions. After the translation process was completed, the questionnaire was administered to forty-five adult polydrug abusers who were residing in a general hospital. Subjects answered the questionnaire on four occasions, describing the feelings they usually experienced under the effects of four classes of drugs of abuse (morphine-like opioids, alcohol, stimulants and hallucinogens). The scales showed an acceptable level of internal consistency. A characteristic pattern of response was obtained for each condition. A discriminant analysis revealed that four scales PCAG (pentobarbital-chlorpromazine-alcohol group), MBG (morphine-benzedrine group), LSD (lysergic acid dyethylamide scale) and BG (benzedrine group) significantly discriminated between the conditions studied. Sixty percent of the questionnaires answered were correctly classified according to the discriminant functions constructed. The results from this study are similar to those obtained with the English ARCI, and suggest that the Spanish version of the 49-item ARCI may be an useful instrument for the evaluation of subjective effects produced by psychoactive drugs in Spanish populations.

CYP1A2-catalyzed conversion of dietary heterocyclic amines to their proximate carcinogens is their major route of metabolism in humans

The contribution of CYP1A2 to the metabolism of the dietary heterocyclic amines, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) in vivo in humans, has been determined with furafylline, a highly selective inhibitor of this enzyme. The inhibitory potential of furafylline in vivo was first assessed by determining its effect on clearance of phenacetin to paracetamol by the model CYP1A2-dependent O-deethylation pathway. Furafylline inhibited this reaction by > 99% in all subjects, thus demonstrating its applicability to determining the contribution of CYP1A2 to a given reaction in vivo. A group of 6 healthy male volunteers received either placebo or 125 mg furafylline, in a double-blind balanced crossover design, 2 h prior to consuming a test meal of fried beef containing a known amount of amines. The excretion of PhIP and MeIQx in urine was determined during the subsequent 28 h, using gas chromatography-mass spectrometry. Following furafylline, the excretion of unchanged MeIQx increased 14.3-fold, while that of PhIP increased 4.1-fold (P < 0.01, paired t test). Elimination of both amines was first order and very rapid, with half-lives of < 5 h. The elimination rate constants did not change following furafylline, suggesting that total clearance is limited by hepatic blood flow. Because the elimination of the amines was first order, it was possible to calculate the contribution of CYP1A2 to the clearance of the amines. CYP1A2-catalyzed metabolism accounts for 91% of the elimination of ingested MeIQx and 70% of ingested PhIP, most likely via N-hydroxylation.

Acute effects of tramadol in methadone-maintained volunteers

The opioid agonist and antagonist properties of tramadol were assessed in 6 male opioid-dependent volunteers enrolled in a methadone maintenance programme. Subjects participated in 3 experimental sessions in which the effects of intramuscular tramadol 100 and 300 mg and placebo were evaluated. Tramadol neither produced morphine-like effects nor precipitated a withdrawal syndrome; its subjective, behavioural and physiological effects were not different from those of placebo. Although the results of this study suggest that tramadol has a low abuse liability in opioid-dependent subjects, higher doses should be tested to confirm these data.

Alcohol and cocaine interactions in humans

The effects of 100 mg of intranasal cocaine (COC) in acute alcohol intoxication (1 g/kg) was assessed in nine experienced and non-dependent healthy volunteers in a double-blind, controlled, randomized, cross-over clinical trial. Alcohol alone impaired psychomotor performance, whereas COC alone produced subjective effects related to euphoria and well-being, improved the reaction time and increased heart rate and blood pressure. The combination of COC and alcohol induced a nonsignificant decrease in the subjective feelings of drunkeness, an increase in COC-induced euphoria, a significant improvement in alcohol-related changes in psychomotor performance and a marked increase in heart rate. Subjects experienced subjective and performance effects that could be self-interpreted as more pleasant compared to the effects of alcohol alone. When alcohol was given simultaneously, COC plasma levels were higher (possibly as a result of an inhibition of hepatic metabolism of COC produced by alcohol), norcocaine plasma levels almost doubled and cocaethylene was detected in plasma, so that its basic pharmacokinetic profile could be described. The simultaneous use of both drugs produced changes in heart rate and blood pressure that could increase the risk of cardiovascular toxicity associated with the use of COC.

Flunitrazepam consumption among heroin addicts admitted for in-patient detoxification

The use of benzodiazepines among 973 heroin addicts admitted for inpatient detoxification over a 10-year period was assessed in a cross-sectional study. A total of 780 (80.2%) patients had a history of benzodiazepine use; 666 (68.5%) were consuming benzodiazepines at the time of admission and 419 (43.1%) on an almost daily basis. Seventy-five (7.7%) patients fulfilled criteria for sedative-hypnotic abuse or dependence. Consumption of benzodiazepines began after subjects had become addicted to heroin. Flunitrazepam was ranked first by 68.4% of patients, followed by clorazepate (13%), and diazepam (12.4%). The prevalence of benzodiazepine use, in particular flunitrazepam, among heroin addicts is very high. Specific abuse liability studies are needed to determine whether pharmacologic reasons exist to explain heroin addicts' preference for this compound.

Pharmacokinetics and tolerance of sertaconazole in man after repeated percutaneous administration

The local and systemic tolerance of 7-chloro-3-[1-(2,4-dichlorophenyl)-2-(1H- imidazol-1-yl)ethoxy-methyl]benzo[b]thiophene (sertaconazole, FI-7045, CAS 99592-32-2) 2% cream was studied in healthy volunteers after cutaneous application in an increasing-dose schedule during 13 days. Blood and urine samples were collected after the application of 16 g of cream. Percentage of absorption was determined in eight 3 x 3 cm areas of the volar arm skin after 2 mg cream topical application. No changes on vital signs (blood pressure, heart rate and body temperature) or in the ECG were found during the trial. Sertaconazole did not produce skin irritation nor systemic side effects. Sertaconazole was not detected in either the serum and urine samples obtained. The percentage of cutaneous absorption at 24 h after administration reached 72% of the applied dose.

[Treatment of acute pain in a general hospital: opinions of physicians and nurses]

A survey was carried amongst physicians and nurses of a general hospital, in order to know their opinion about acute pain treatment. Out of 106 physicians and 153 nurses questioned, 72 and 105 respectively answered the questionnaire. Two thirds of them though that analgesic treatment was currently good, although, it could be improved if they increased their knowledge about it. Twenty nine per cent of physicians thought that their patients were receiving lower doses than what they had prescribed and that this fact could be responsible for the treatment failure. Those questioned believed that approximately 30% of patients treated with opium derivatives for over a week could develop addiction problems. Our study confirmed the existence of inadequate attitudes towards the need for analgesics in patients with acute pain.

Pharmacokinetic considerations in abuse liability evaluation

The behavioral effects of a drug are related to three factors: its intrinsic pharmacological activity, its physicochemical properties, and its pharmacokinetic parameters. In many cases differences in absorption, distribution, metabolism, and elimination may explain the different abuse liability profiles of drugs from within the same pharmacological class. Rapid absorption rate and high lipid solubility are the most important factors contributing to early drug concentrations in the brain. Differences in drug metabolism may be related to dose-dependent kinetics, first-pass metabolism, and variations in genetic traits (e.g. poor or extensive metabolizers). Metabolic pathways may produce active metabolites with similar or greater pharmacological activity than the parent substance. Drugs with a rapid elimination rate have been associated with greater self-administration and with early emergence of withdrawal symptoms. More pharmacokinetic studies are needed in human drug abuse liability evaluations. Knowledge of the plasma concentrations of drugs and their pharmacokinetic parameters can be essential to interpret differences among similar drugs in human abuse liability assessments.

[Digestive manifestations and metabolic acidosis secondary to intravenous administration of cotrimoxazol]

BACKGROUND

Digestive features and metabolic acidosis have been observed in patients with Pneumocystis carinii pneumonia treated with intravenous high dose co-trimoxazole.

METHODS

To evaluate this phenomenon, a retrospective study of 22 patients (group A) and a prospective study of 12 patients (group B) were carried out. Group B patients were investigated following a protocol lasting for the 21 days of treatment.

RESULTS

Metabolic acidosis developed in 23 (67%) of the overall number of study patients, and it was associated with digestive features such as nausea, vomiting and epigastralgia in 12. One patient had digestive features without metabolic acidosis. Metabolic acidosis developed early, between the days 4 and 7 of administration of the drug. The mean value of bicarbonate at the onset of therapy was 24,55 mEq; the mean value in the patients with metabolic acidosis was 16,43 mEq. The overall mean value of base excess at the onset of therapy was -2,39, and it was -8,46 in the patients who developed metabolic acidosis.

CONCLUSIONS

As in all patients other causes of metabolic acidosis were ruled out, it became obvious that intravenous co-trimoxazole was directly related to the development of digestive features and metabolic acidosis, which disappeared with bicarbonate administration or with cessation of therapy.

Drug-induced priapism. Its aetiology, incidence and treatment

Priapism is characterised by a persistent erection that cannot be relieved by sexual intercourse or masturbation. Although priapism subsides spontaneously in a few days, impotence frequently follows. Both vascular and neural mechanisms are implicated in the pathophysiology of priapism, but it is not clear which initiates the process. Idiopathic cases of priapism are the most frequent (near 50%); other medical conditions that can result in priapism are haematological diseases (mainly sickle cell anaemia and leukaemia), traumatism, and neoplastic processes. Drug-induced priapism comprises about 30% of cases. The drugs most frequently implicated are psychotropic drugs (phenothiazines and trazodone), antihypertensives (mainly prazosin) and heparin. Recently, the intracavernosal injection of vasoactive drugs (papaverine and phentolamine) has been described in patients treated for impotence. With the exception of heparin, an alpha-adrenergic blocking mechanism has been suggested in the priapism-inducing action of these drugs. A significant number of anecdotal case reports link priapism and drugs, and it is possible that certain cases of idiopathic priapism could be reclassified if accurate pharmacological anamnesis were to be performed. Priapism must be considered a urological emergency. Surgical procedures are the most preferred treatment for this condition but, in selected cases, drug treatment seems to be an alternative approach.

Comparison of the nephrotoxicity and auditory toxicity of tobramycin and amikacin

A total of 157 patients were treated with tobramycin or amikacin in a controlled prospective randomized trial. Dosages were adjusted to renal function according to a nomogram. Trough and peak aminoglycoside levels were available at the end of the trial. Of the above total, 113 recipients of nine or more doses of tobramycin or six or more doses of amikacin, without other apparent cause of renal failure, were evaluated for nephrotoxicity. Thirty-six patients were evaluated for auditory toxicity. The patients in groups evaluated for either nephrotoxicity or auditory toxicity were similar with respect to intensity and etiology of bacterial disease, concurrent exposure to other antimicrobial drugs, age and sex distribution, initial serum creatinine level, and total dose and duration of antimicrobial therapy. Nephrotoxicity of similar severity developed in 4 of 59 (6.8%) recipients of tobramycin and in 7 of 54 (13.1%) recipients of amikacin (P greater than 0.05). Mild auditory toxicity developed in 3 of 19 (15.7%) recipients of tobramycin and in 2 of 17 (11.7%) recipients of amikacin (P greater than 0.05). When patients with abnormally high mean trough or peak aminoglycoside levels were excluded from comparison, nephrotoxicity was 6.12 and 5.12% (P greater than 0.05) and auditory toxicity was 17.6 and 7.69% (P greater than 0.05) in the groups given tobramycin and amikacin, respectively. We conclude that the nephrotoxicity and auditory toxicity of amikacin and tobramycin are not significantly different and that such toxicities are indeed infrequent events when the dosages of these drugs are adjusted to hold blood levels within the safe boundaries suggested by the studies of others.