Voriconazole-Induced QT Interval Prolongation and Ventricular Tachycardia: A Non--Concentration-Dependent Adverse Effect

A 15-year-old patient with acute lymphoblastic leukemia and Fusarium infection was treated with voriconazole. She developed asymptomatic bradycardia, QT interval prolongation, and nonsustained, polymorphic ventricular tachycardia, which recurred upon rechallenge with the drug. Voriconazole levels and metabolism were within expected normal values. This non-concentration-dependent, voriconazole-associated ventricular tachycardia mandates cardiac rhythm monitoring during voriconazole treatment.

Local effect of transdermal isosorbide dinitrate ointment on hand vein diameter

OBJECTIVE

To assess the effect of topically applied isosorbide dinitrate (ISDN) ointment on superficial hand veins preconstricted with phenylephrine.

METHODS

Using the hand vein compliance technique, venous diameter changes were measured in a double-blind, randomised, placebo-controlled cross-over trial in 12 healthy volunteers. During preconstriction with phenylephrine, placebo or ISDN ointment was administered to assess the dilator effect of transdermal ISDN. Finally a single i.v. dose of nitroglycerine was administered into the hand vein to assess the maximal venous response to organic nitrovasodilators.

RESULTS

ISDN ointment (equivalent to 13.4 +/- 3.61 mg ISDN) caused a significant dilator effect of 39.1 +/- 21.7% (mean +/- SEM, P=0.02) which reached its maximum after 42.5 +/- 16.6 min. Maximum ISDN effects were inversely correlated with venous baseline diameter (r2=0.38, P=0.03) and independent of the amount of ointment applied or the extent of preconstriction (P > 0.3).

CONCLUSION

Similar to nitroglycerine, topical ISDN may relax superficial hand veins within 60 min after application, suggesting that it might ease venepuncture particularly of small vessels. The large variability of the effect and the time to reach the effect, however, restrict its practical usefulness.

Ritonavir increases loperamide plasma concentrations without evidence for P-glycoprotein involvement

BACKGROUND

The antidiarrheal drug loperamide is frequently used to treat ritonavir-associated diarrhea in patients with human immunodeficiency virus. The absence of marked central opioid effects has been attributed to its low bioavailability and its poor penetration of the blood-brain barrier, both of which might be altered by ritonavir, a potent P-glycoprotein and cytochrome P4503A inhibitor.

METHODS

A 16-mg dose of loperamide was administered to 12 healthy male and female volunteers together with either 600 mg of ritonavir or placebo. Detailed pharmacokinetics of loperamide and its metabolites were determined over 72 hours. Central opioid effects were measured by evaluation of pupil diameter, cold pressor test, and transcutaneous PCO2 and PO2.

RESULTS

Ritonavir caused a major pharmacokinetic interaction, increasing the area under the concentration-time curve of loperamide from 104 +/- 60 h x pmol/ml after placebo to 276 +/- 68 h. pmol/ml and delayed formation of the major metabolite desmethylloperamide (time to reach maximum concentration after drug administration [t(max)], 7.1 +/- 2.6 hours versus 19.6 +/- 9.1 hours). The urinary metabolic ratio of loperamide increased 3 times whereas the total molar amount of loperamide and metabolites excreted in urine remained unchanged. No central pharmacodynamic effects were observed after coadministration of loperamide with either ritonavir or placebo.

CONCLUSION

This study demonstrates a major metabolic interaction probably by cytochrome P4503A4 with no evidence of P-glycoprotein involvement. This might explain the lack of central effects after ritonavir.

Risk of cataract in patients treated with statins

BACKGROUND

Studies in dogs showed that some hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) are associated with cataract when administered in excessive doses. Clinical safety data of statins regarding cataract development in humans have been of limited value so far.

OBJECTIVE

To determine whether long-term use of statins is associated with an increased risk of cataract.

METHODS

We conducted a case-control analysis using data from the United Kingdom-based General Practice Research Database. The main outcome was a first-time diagnosis of cataract and/or cataract extraction in patients aged 40 to 79 years. Controls were matched to cases on age, sex, practice, calendar time, and duration of medical history in the database. Use of statins, fibrates, or other lipid-lowering drugs was compared with nonuse of any lipid-lowering drug, stratified by exposure duration and dose.

RESULTS

We identified 7405 cases and 28 327 controls. Long-term use of statins (eg, > or =30 prescriptions) was not associated with an increased cataract risk (adjusted odds ratio [OR], 0.9; 95% confidence interval [CI], 0.5-1.6), nor was use of fibrates or of other lipid-lowering drugs (adjusted OR, 0.5; 95% CI, 0.3-1.1; and OR, 0.7; 95% CI, 0.1-5.6, respectively). We found evidence that concomitant use of simvastatin and erythromycin, a potent inhibitor of simvastatin metabolism, is associated with an increased cataract risk (adjusted odds ratio, 2.2; 95% confidence interval, 1.2-4.1).

CONCLUSIONS

Our study provides evidence that long-term use of therapeutic statin doses does not increase the risk of developing cataract. Concomitant use of erythromycin and simvastatin may increase the cataract risk.

Drug dosage in patients with renal failure optimized by immediate concurrent feedback

OBJECTIVE

To examine the impact of immediate concurrent feedback on dose adjustment in patients with renal failure.

DESIGN

Prospective 12-month study in patients with various degrees of renal failure, with comparison to a retrospective control group.

SETTING

A 39-bed unit of a university hospital providing primary and tertiary care.

PATIENTS

Patients with renal failure (estimated creatinine clearance < or = 50 mL/min) receiving at least 1 pharmacologically active drug.

INTERVENTIONS

Education of physicians and immediate concurrent feedback on the ward giving estimated creatinine clearance and dose recommendations for renally eliminated drugs adjusted to individual renal function.

MEASUREMENTS AND MAIN RESULTS

The percentage of dosage regimens adjusted to renal function and cost assessment of drug therapy were calculated. Overall, 17% of the patients had at least 1 estimated creatinine clearance < or = 50 mL/min. In the intervention group, the dose of 81% of renally eliminated drugs was adjusted to renal function, compared with 33% in the control group ( P <.001). The mean difference in cost between standard and adjusted dose of renally eliminated drugs in the intervention and control groups was 5.3 +/- 12.3 and 0.75 +/- 2.8 Swiss francs (approximately US$3.5 and US$0.5), respectively ( P <.001), accounting for 16.5% and 2.8%, respectively, of daily medication costs of all drugs.

CONCLUSIONS

The proportion of doses of renally eliminated drugs adjusted to renal function can be substantially increased by immediate concurrent feedback. This saves drug costs and has the potential to prevent adverse drug reactions.

Disturbed ratio of erythrocyte and plasma S-adenosylmethionine/S-adenosylhomocysteine in peripheral arterial occlusive disease

Altered homocysteine metabolism associated with peripheral arterial occlusive disease (PAOD) may lead to impairment of vital methylation reactions through accumulation of S-adenosylhomocysteine (AdoHcy) as well as through alteration of the ratio S-adenosylmethionine (AdoMet)/AdoHcy. We determined AdoMet, AdoHcy, their ratio, and homocysteine in plasma as well as AdoMet, AdoHcy, and their ratio in erythrocytes of 61 patients with PAOD (age 49-93) and 50 healthy controls (age 41-87). Geometric mean values of plasma homocysteine, AdoMet, and AdoHcy were significantly increased in patients compared with controls (15.5 vs. 10.4 micromol/l**; 107 vs. 52.3* nmol/l; 55. 0 vs. 23.1** nmol/l, respectively; *P<0.01, **P<0.001), while the ratio of AdoMet/AdoHcy was decreased in patients (1.92 vs. 2.52*). In erythrocytes patients exhibited increased levels of AdoHcy compared with controls (309 vs. 205 nmol/l**) whereas AdoMet (3351 vs. 3732 nmol/l*) and the ratio of AdoMet/AdoHcy (11.8 vs. 19.1**) were decreased. The odds ratio (OR) for developing PAOD with decreased AdoMet/AdoHcy ratio after adjustment for kidney function was significant for erythrocyte levels < or =14.2 (OR, 7.1 (6.9-7.2, 95% CI). In addition, hematocrit levels were found to be significantly decreased in patients versus controls (0.35 vs. 0.42 l/l**) and were significantly correlated with the ratio of AdoMet/AdoHcy in erythrocytes of the patients. Since the ratio of AdoMet/AdoHcy is closely linked with the activity of numerous enzymatic methylation reactions, these results suggest that methylation may be impaired in these patients.

Effect of P-glycoprotein modulation on the clinical pharmacokinetics and adverse effects of morphine

AIMS

To investigate the effect of acute P-glycoprotein inhibition by the multidrug-resistance (MDR) modulator valspodar (SDZ PSC 833; PSC) on the pharmacokinetics, and potentially adverse pharmacodynamic effects of morphine, and its principal pharmacologically active metabolites, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G).

METHODS

In a double-blind, three-way crossover study, the pharmacokinetic and potentially adverse pharmacodynamic effects (reaction time, transcutaneous PCO2, blood pressure) of morphine were compared with and without acute inhibition of P-glycoprotein by PSC. The effects of PSC alone were also evaluated. The study was performed in 18 healthy male volunteers and pharmacodynamic effects analysed by measuring the area under the effect (AUE) curve. 150 mg PSC (or its placebo) was given as an i.v. infusion over 2 h. With the expected inhibition of Pgp 1 h after starting PSC infusion, 7.5 morphine HCl (or its placebo) was infused over 2 h.

RESULTS

The infusion of PSC resulted in blood concentrations expected to inhibit Pgp mediated transport. While the pharmacokinetics of plasma morphine and M6G. were unaffected there was a small but statistically significant increase in the AUC and Cmax of M3G (11.8 and 8.3%, respectively). The t(1/2) and tmax were unaffected. The pharmacokinetic parameters of PSC were not affected by coadministration with morphine. PSC did not significantly affect the adverse events of morphine, as assessed by spontaneous reporting. Compared with PSC alone, morphine elicited an increase in reaction time (Emax 48 ms, compared with the predose absolute reaction time of 644 ms), which was not detected by the alertness-drowsiness score, indicating only slight sedation. There was a significant decrease in systolic blood pressure (Emin -9 mm Hg), and a trend for a fall in diastolic blood pressure (Emin -14.5 mm Hg) and respiratory rate (Emin -1.8 breath x min(-1)). For all these parameters, the effects of PSC/morphine were similar to that of PSC alone, suggesting some attenuation of morphine's effect. In contrast, morphine caused a significant increase in PCO2 (Emax 0.69 kPa) compared to PSC alone, indicating slight respiratory depression. This increase was similar to that of the PSC/morphine combination.

CONCLUSIONS

Acute inhibition of P-glycoprotein by PSC in this setting does not affect the pharmacokinetic or safety-related pharmacodynamic profile of morphine in a clinically significant manner.

[Consideration of drug absorption in customizing drug therapy]

The rate and extent of drug absorption from the small intestine are related to the release of the active ingredient from a dosage form, its solubility in the liquid phase of gastrointestinal contents, and the transport of the dissolved compound or the intact dosage form from the stomach into the duodenum. With pharmaceutical preparations releasing the active compound within the stomach, and enteric-coated "micro"-formulations (micropellets), gastric emptying is possible during the interdigestive and the digestive period. Potential differences of drug absorption between fasting administration and intake during the digestive period are unpredictable, because they are related to the release characteristics of the dosage form. However, larger enteric-coated preparations like tablets can leave the stomach only with a phase 3 contraction of fasting motility; intake during the digestive period will result in gastric retention of this type of dosage form until all food has left the stomach and fasting motility is restored. Consequently the onset of drug absorption is delayed. This interaction between food and large enteric-coated dosage forms is predictable from pyloric function in relation to the gastric motility. As it occurs regularly, it can be taken into account when prescribing enteric-coated dosage forms. If concomitant intake of food and enteric-coated drugs is unavoidable, but a rapid onset of drug absorption is necessary, micropellets are the dosage form of choice. When the therapeutic effect is insufficient, drug dosage form and timing of drug administration should be checked before prescribing a different active compound.

[Individualized drug therapy--need for improvement]

The lack of dose adjustment to the individual needs of a patient is a major cause for the substantial difference between the efficacy of therapies established in large trials and the therapeutic results obtained in everyday practice (reduced effectiveness). In addition, these differences affect drug safety and ultimately also costs. Hence strategies to maintain good compliance and to avoid incompatibilities, drug interactions and adverse events should be applied whenever drugs are prescribed. This supplement compiles different techniques and measures which may support health professionals in reaching these goals.

[Clinically relevant adverse drug interactions]

Drug interactions may lead to adverse drug effects or therapeutic failure. Many clinically relevant unwanted interactions are caused by a change in the activity of cytochrome P450 isoenzymes or the activity of active drug transport systems (e.g. p-glycoprotein). Most drug interactions may be anticipated and prevented by dose modification or using alternative drugs.

The mechanism of cryoinjury: In vitro studies on human internal mammary arteries

The mechanism of cryoinjury was investigated in human internal mammary arteries (IMA) by monitoring contractile responses to ET-1 and KCl. For cryopreservation segments of IMA were equilibrated for 20 min with the cryomedium (RPMI 1640 culture medium containing 1.8 M DMSO and 0.1 M sucrose), frozen at a mean cooling rate of 1.3 degrees C min(-1) to -70 degrees C and stored in liquid nitrogen. Before use, samples were thawed slowly and the cryomedium removed by dilution. Compared to unfrozen controls, ET-1 stimulated frozen/thawed IMA with similar efficacy but at 3 fold lower concentrations (P<0.001). Addition of ET-1 (100 nM) induced maximal contraction of unfrozen IMA within 10 min, declining thereafter to 25% after 90 min. In frozen/thawed IMA the ET-1-induced contraction was sustained but could be reversed if protein kinase C was blocked by staurosporine (100 nM). Responses to ET-1 of cryostored IMA were 5 fold more susceptible to blockade by nifedipine than those of controls. After cryostorage the efficacy of KCl was diminished to 40% (P<0.05) and the KCl curve was shifted to the left (2 fold, P<0. 001). In both unfrozen and cryostored IMA the KCl (60 mM) effect was sustained and equally susceptible to nifedipine. It is suggested that the smooth muscle cell of IMA is receptive to physical forces which occur during cryopreservation. These forces modify transmembrane signal transduction and intracellular pathways, that are common to pharmacological agonists thereby changing vascular responses to several contractile agonists after thawing.

Correlation between apolipoprotein B and endothelin-1-induced vasoconstriction in humans

Low-density lipoprotein (LDL) concentrations have been linked to altered responses to endogenous vasodilators and vasoconstrictors. We evaluated retrospectively the relationship between LDL and vasoconstrictor (endothelin-1, phenylephrine) responsiveness of the forearm vasculature in 15 elderly healthy volunteers with apolipoprotein B and LDL levels in the normal range. In contrast to phenylephrine, changes in forearm vascular resistance induced by endothelin-1 were correlated with apolipoprotein B, LDL, and total cholesterol concentrations in women but not in men. These findings might suggest that lipids may increase vascular tone through both impaired endothelial vasodilation and increased vasoconstriction to endothelin-1 at least in women.

Inspired oxygen fraction after cardiopulmonary bypass: effects on pulmonary function with regard to endothelin-1 concentrations and venous admixture

Twenty consecutive patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) were allocated at random to group 1 (n = 10, high inspired oxygen fraction (FIO2) after CPB), or group 2 (n = 10, moderate FIO2 after CPB). The effects of each FIO2 on arterial and mixed venous concentrations of endothelin-1 (ET-1) and its precursor, Big ET-1, were measured. Venous admixture was calculated to assess the efficiency of pulmonary gas exchange. Patients whose lungs had been ventilated with a FIO2 of 1.0 (exposure time 70 min) after weaning from the CPB machine had significantly greater arterial and mixed venous Big ET-1 concentrations and venous admixture than patients whose lungs were ventilated with a FIO2 of 0.35. In contrast, ET-1 concentrations in the two groups were not significantly different. A reduction of FIO2 from 1.0 to 0.6 reduced venous admixture without lowering endothelial peptide concentrations. On the first postoperative day all peptide concentrations were similar in the two groups, whereas venous admixture remained non-significantly higher in group 1. A short period of high FIO2 immediately after CPB increases endothelin concentrations and pulmonary venous admixture.

Overconsumption detected by electronic drug monitoring requires subtle interpretation

BACKGROUND

Electronic compliance monitoring has provided new variables to describe drug intake behavior and new strategies to improve compliance. However, as evaluated in this study, the recording of opening events of pill bottles does not necessarily mean drug intake.

METHODS

In an open 3-week trial with an oral vitamin combination, drug intake was recorded with use of an electronic pill box that contained 25 capsules and that registered each opening of the bottle. Thirty-seven patients were asked to take one capsule every morning for 21 days. Opening and closing events were related to the results of pill counts and patient interviews at the end of the trial.

RESULTS

Drug consumption was 101.8% (663 recorded opening and closing events) in the 31 patients who completed the trial. Pill boxes were opened more than once by 10 patients on at least one monitored day. For seven patients the total number of openings was >25 (range, 26 to 29) and thus exceeded the number of capsules provided. A third interview of these patients revealed real overconsumption in only two patients. Six patients remembered that they had shown the device to relatives or friends or that they had checked to see whether they had closed the pill box well, thus turning a "curiosity event" into a drug intake event.

CONCLUSION

In short-term studies particularly, such curiosity events may substantially modify the electronic assessment of compliance surrogates. In these trials the combined evaluation of electronic openings, pill counts, and interviews may be a suitable way to reveal such openings without pill intake.

Auditory and electroencephalographic effects of midazolam and alpha-hydroxy-midazolam in healthy subjects

AIMS

Whereas cortical EEG effects of benzodiazepines are well characterized, information about benzodiazepine effects in other areas of the central nervous system is sparse. This study investigated the action of midazolam and its active metabolite alpha-hydroxy-midazolam on different parts of the auditory pathway in six healthy volunteers in a randomized, double-blind, three-way cross-over study.

METHODS

Acoustically evoked short (SLP) and middle (MLP) latency potentials, transitory evoked otoacoustic emissions (TEOAE), and EEG power spectra were analysed after short i. v. injections of placebo, or 0.15 mg kg-1 midazolam, or alpha-hydroxy-midazolam, respectively.

RESULTS

All subjects fell asleep during the 4 min infusion of active drug. SLP showed a significant transient increase of Jewett wave V 10 min after injection for midazolam and alpha-hydroxy-midazolam while the latency of wave I was unchanged. Both benzodiazepines induced a marked and long-lasting MLP amplitude decrease for 240 min with slow recovery over the following 360 min. No changes of TEOAE were observed. In agreement with earlier reports, increases in EEG beta activity and decreases in alpha activity were observed after administration of either drug.

CONCLUSIONS

Systemically administered benzodiazepines modulate the auditory pathway above the level of the cochlea. While SLP changes were closely associated with sedation and high plasma benzodiazepine concentrations, MLP effects persisted for hours after sedation even at low benzodiazepine plasma levels. Evoked potentials may therefore be more sensitive than EEG as a tool to monitor benzodiazepine effects.

Methylenetetrahydrofolate reductase polymorphism, plasma homocysteine and age

BACKGROUND

Elevated fasting levels of total homocysteine are now accepted as an independent risk factor for the development of arteriosclerotic vascular diseases. A polymorphism in the gene encoding methylenetetrahydrofolate reductase (MTHFR), caused by the C677T point mutation, leads to increased thermolability of the enzyme, with reduced enzyme activity. We studied the frequency of this mutation in different groups of the Swiss adult population.

PATIENTS AND METHODS

DNA from 361 subjects was screened for the thermolabile MTHFR variant with PCR. Included were healthy subjects without vascular disease (n = 118), older healthy subjects (n = 106), patients with coronary artery disease (CAD, n = 75), and patients with peripheral arterial occlusive disease (PAOD, n = 63).

RESULTS

In the different groups studied, homozygosity for the mutation ranged from 4.8 to 16.2%, with a frequency of 16.2% in the healthy cohort. The allele frequencies of the thermolabile allele were 38.5 and 27.3 in young and old controls, and 37.3 and 33.3 in CAD and PAOD patients. In the healthy younger subjects the mutant allele was 1.4 times more frequent compared to the older subjects (P = 0.01). No difference in either MTHFR genotype distribution (P = 0.33) or allele frequencies (P = 0.48) between patients and controls was found. Except for the PAOD group with elevated tHcy levels for the +/+ carriers compared to the other genotypes, no statistically significant difference was found comparing homocysteine levels with genotype.

CONCLUSION

This study shows no link between the mutation and the occurrence of vascular disease but we found evidence pointing to a correlation between the mutation and longevity in our population.

Isoniazid plus sulphadoxine-pyrimethamine can reduce morbidity of HIV-positive patients treated for tuberculosis in Africa: a controlled clinical trial

An annual 20% excess mortality rate is observed in HIV-seropositive patients after treatment for tuberculosis. An affordable secondary prophylaxis against main opportunistic diseases is needed, i.e. against tuberculosis, toxoplasmosis, pneumocystosis and other infections occurring in this target population. This open prospective randomized study assessed morbidity and mortality in 2 cohorts of HIV-seropositive patients having recently recovered from pulmonary tuberculosis: 134 patients assigned to prophylactic treatment with isoniazid (INH, 300 mg once daily) plus sulphadoxine-pyrimethamine (S, 500 mg/P, 25 mg once weekly), and 129 were controls, comparable for sex, age, weight and HIV-serology. Patients were followed-up for up to 2 years: 192 person-years (PY) in the prophylaxis group and 142 PY in the control group. Four patients developed tuberculosis and 20 patients died in the prophylaxis group, compared to 10 and 23 controls, respectively. Sick days were reported by 22 patients in the prophylaxis group and by 77 patients in the control group. This prophylaxis was associated with a moderate decrease of mortality (log rank test: p = 0.1736), a significant decrease of tuberculosis incidence (log rank test: p = 0. 0234), a highly significant reduction of adverse events and sick days, and a prevention of wasting (p = 0.008) and anaemia (p = 0. 045). No death from toxoplasmosis occurred in the prophylaxis group as compared to 2 possible cases among controls; toxoplasmosis IgG levels declined in treated patients, but increased in controls (p = 0.01). There was no adverse drug reaction due to SP (10,006 doses) or to INH. Compliance with SP intake was good, but moderate as with INH intake. We conclude that a secondary prophylaxis with INH+SP represents a cost-effective measure to improve health conditions of HIV-infected adults in Côte d'Ivoire, following a full treatment course against tuberculosis.

Neurokinin-1 receptor antagonist R116301 inhibits substance P-induced venodilation

OBJECTIVE

To test the effect of the neurokinin-1 receptor antagonist hydroxybutanedioate (R116301) in human hand veins in vivo.

METHODS

In a randomized, double-blind, placebo-controlled crossover study we used the hand vein compliance method to evaluate the inhibition of the response to substance P by R116301.

RESULTS

In hand veins preconstricted with phenylephrine to 21% +/- 2.6% (mean +/- SEM, placebo) and 25% +/- 3.0% (R116301) of the initial diameter, substance P resulted in a mean venodilation of 84% +/- 7% and 87% +/- 13% (P = .8) before administration of placebo and R116301, respectively. Oral administration of 300 mg R116301 resulted in peak plasma concentrations of 1.16 +/- 0.1 microg/mL within 128 +/- 14 minutes. With increasing R116301 plasma concentrations, substance P-induced venodilation decreased significantly (P < .001), whereas placebo had no effect. Mean substance P-induced venodilation was markedly reduced to 8% +/- 7%.

CONCLUSION

This study confirms the presence of neurokinin-1 receptors in human veins and the effectiveness of the neurokinin-1 receptor antagonist R116301 in human hand veins.

[Conviction as a basis for compliance and strategies for improving compliance]

The aim of the present study was to correlate statements made by 100 patients of an internal medicine ward regarding their compliance before hospitalization, with their personal knowledge of an convictions about their own pharmacotherapy. Data were collected in structured interviews of 9 questions carried out by a medical person not involved in current treatment. The patient sample (mean age +/- SE: 6.8 +/- 1.3 years) included 42 women and 58 men whose mean number of prescribed medications before hospitalization was 4.7 +/- o.22. Good treatment compliance was reported by 78% of the patients, while 13% admitted non- compliance. Knowledge about the drugs they had been prescribed ranged from perfect (30%) to none (34%) and was significantly different between compliers and non-compliers, with patients who know their medications at least by name being fairly compliant (p = 0.048). Independently of the statement about compliance, the patients used three main strategies to ensure regular intake of daily medication: visual aids (69%), coupling to a ritual (26%) or supervision by a third person (6%). Criteria such as gender, the number of prescribed medications, personal perseverance, or personal definition of the sense of the prescribed pharmacotherapy, or the arguments expected to be used by a physician when recommending a pharmacotherapy did not differ between compliers and non-compliers. Thus, compliance appears to have its roots mainly in the conviction level of each patient : intention will be transformed into action when deemed correct according to the individual's personal criteria. This may lead to both compliance and to non-compliance with medical recommendations. This study, which is based on patient reports, supports the conclusion that drug compliance may be enhanced by increasing patient's knowledge about their own pharmacotherapy and by having patients use specific strategies to guarantee regular daily intake of drugs. Prospective studies should therefore address the question of whether providing specific information according to a patient's convictions will untimately translate into improved compliance.

[Anticonvulsant hypersensitivity syndrome. 2 case reports and an overview]

Anticonvulsants with aromatic ring structure such as phenytoine, carbamazepine, phenobarbital and lamotrigine can induce a drug hypersensitivity syndrome ("anticonvulsant hypersensitivity syndrome", AHS). Though the incidence of AHS is low, correct and early diagnosis are crucial to stop further progression by immediately withholding the causative drug. AHS usually starts within the first 2-8 weeks after initiation of therapy with fever, followed over the next 1-2 days by a cutaneous reaction and lymphadenopathy. The skin reaction is usually exanthematous but can also manifest itself as Stevens-Johnson or Lyell syndrome. AHS is commonly associated with symptomatic or asymptomatic internal organ involvement usually affecting the liver, although haematologic, renal or pulmonary impairment may also occur. We report two cases illustrating the clinical course and discuss theories about the potential pathogenesis and the treatment of AHS.

Academic detailing improves identification and reporting of adverse drug events

In a prospective, crossover study, we assessed the impact of a clinical pharmacist on identification and reporting of adverse drug events (ADEs) in hospitalized patients. The study was conducted on four units of a medical ward of a university hospital, with two units serving as test, the other two as control units. After 12 months, test and control units were switched. In the test units, a pharmacist participated in daily ward rounds, solicited additional information from physicians and nurses, and reviewed the charts of all patients. In control units, information on ADEs was based solely on voluntary reports from physicians and nurses. A total of 1,959 patients (941 in test, 1,018 in control units) were hospitalized during the study period. In 137 test units patients, 224 ADEs (14.6%; 95%-CI: 12.3%-16.9%) were detected (8 severe, 60 moderate, 156 mild), while 25 ADEs (1 severe, 11 moderate, 13 mild) occurring in 21 patients (2.1%; 95%-CI: 1.2%-3.0%) were reported from the control units (p < 0.0001). Of the ADEs in the test units, 51% were reported spontaneously, 39% were identified on rounds, and 10% by chart review. After changing the status of test and control units, the number of identified ADEs returned to preintervention levels. Clinical pharmacists as part of the medical care team can improve the identification of ADEs which may ultimately translate into improved quality of care.

Pharmacokinetics and pharmacodynamics of clomethiazole after oral and rectal administration in healthy subjects

Clomethiazole, a sedative-hypnotic and anticonvulsant drug, has been successfully administered orally and intravenously, but in cases where either of these methods presents complications, rectal administration may represent a practical alternative. We sought to compare the single-dose pharmacokinetics and pharmacodynamics of clomethiazole after oral and rectal administration. Ten healthy adult volunteers were given 600 mg clomethiazole edisylate (corresponding to 390 mg clomethiazole base) in 2 capsules as a single oral or rectal dose in a double-masked, double-dummy, crossover fashion. Serum concentrations were measured up to 10 hours after administration using a specific high-performance liquid chromatography method. Computerized reaction-time measurement and visual analogue scales (VAS) were used to assess drug effects. Peak serum concentrations were significantly higher after oral administration (mean +/- SEM, oral 1.76 +/- 0.47 microg/mL vs rectal 0.48 +/- 0.14 microg/mL; P = 0.03) and appeared earlier (55 +/- 12 vs 89 +/- 11 min; P = 0.04). Area under the concentration-time curve values were similar after administration by both routes (oral 116 +/- 20.6 vs rectal 105 +/- 36.0 microg x min/mL), with a relative rectal bioavailability of 90% compared with oral administration. The objective pharmacodynamic effects on reaction time (increase of 104 +/- 26 vs 66 +/- 22 ms, oral vs rectal) and working speed (decrease of 132 +/- 38 vs 97 +/- 32 ms, oral vs rectal) were not significantly different. Subjective pharmacodynamic effects, as measured on the VAS, were comparable with both routes of administration. Clomethiazole was well tolerated, with a similar adverse effect profile for both routes of administration. The effects of rectal dosing of clomethiazole were similar to those of oral dosing but appeared to occur later. Our results suggest that rectal administration of a single 600-mg clomethiazole edisylate dose bears no safety risk. Therefore, rectal administration could be considered when neither oral nor parenteral administration is possible and a later onset of effect is not critical.

[Tablets in stool? A common problem!]

Patients and their physicians are often thrown into doubt by the excretion of apparently intact tablets in stools after oral drug administration. This occurs whenever patients receive certain pharmaceutical forms designed to prolong the rate of drug release. The active compound is continuously released during intestinal passage of these pharmaceutical forms and their insoluble coats are visibly excreted into stools wholly or in part. The assumption that the drug was not released from the tablet in these cases is therefore erroneous and no further action is required.