Simultaneous quantification of 55 psychotropic drugs and metabolites in human plasma with a fast UPLC-MS/MS method

OBJECTIVES

Therapeutic drug monitoring is strongly recommended for psychotropic drugs, which present a strong inter- and intra-individual variability due to multiple factors like inflammatory state, smoking, diet, drug interactions due to polypharmacy, and genetic profile. The aim of this study was to develop and validate a fast, simple, and sensitive method allowing the simultaneous quantification of a large number of psychotropic drugs.

METHODS

After a simple sample preparation with a one-step protein precipitation, a total of 55 compounds, including 22 antidepressants, 18 antipsychotics, 2 other psychotropic drugs (bupropion and nefopam), and their metabolites, was separated on a Waters Acquity HSS T3 ultra-performance liquid chromatography column, and subsequently detected and quantified by a triple quadrupole Quantis mass spectrometer with electrospray ionization operated in positive mode.

RESULTS

Total run time was only 5.7 min. Limits of detection ranged from 0.01 to 0.18 µg/L depending on compound. Measuring ranges were from 0.195 to 1000 µg/L depending on compound, and were defined according to therapeutic ranges. Inter- and intra-assay precisions values were less than 15 %. After validation, this method was successfully applied in daily practice for therapeutic drug monitoring of polymedicated psychiatric patients.

CONCLUSION

We developed and validated one of the most sensitive and complete UPLC-MS/MS methods in psychopharmacology, allowing the simultaneous determination of 55 psychotropic drugs in only 5.7 min after a simple sample preparation. This method has been successfully used in daily practice for therapeutic drug monitoring of psychiatric patients and is especially useful in polymedicated patients.

Microelimination or Not? The Changing Epidemiology of Human Immunodeficiency Virus-Hepatitis C Virus Coinfection in France 2012–2018

Background

The arrival of highly effective, well-tolerated, direct-acting antiviral agents (DAA) led to a dramatic decrease in hepatitis C virus (HCV) prevalence. Human immunodeficiency virus (HIV)-HCV–coinfected patients are deemed a priority population for HCV elimination, while a rise in recently acquired HCV infections in men who have sex with men (MSM) has been described. We describe the variations in HIV-HCV epidemiology in the French Dat’AIDS cohort.

Methods

This was a retrospective analysis of a prospective cohort of persons living with HIV (PLWH) from 2012 to 2018. We determined HCV prevalence, HCV incidence, proportion of viremic patients, treatment uptake, and mortality rate in the full cohort and by HIV risk factors.

Results

From 2012 to 2018, 50 861 PLWH with a known HCV status were followed up. During the period, HCV prevalence decreased from 15.4% to 13.5%. HCV prevalence among new HIV cases increased from 1.9% to 3.5% in MSM but remained stable in other groups. Recently acquired HCV incidence increased from 0.36/100 person-years to 1.25/100 person-years in MSM. The proportion of viremic patients decreased from 67.0% to 8.9%. MSM became the first group of viremic patients in 2018 (37.9%). Recently acquired hepatitis represented 59.2% of viremic MSM in 2018. DAA treatment uptake increased from 11.4% to 61.5%. More treatments were initiated in MSM in 2018 (41.2%) than in intravenous drug users (35.6%). In MSM, treatment at the acute phase represented 30.0% of treatments in 2018.

Conclusions

A major shift in HCV epidemiology was observed in PLWH in France from 2012 to 2018, leading to a unique situation in which the major group of HCV transmission in 2018 was MSM.

Clinical Trials Registration. NCT02898987.

Determination of free extracellular levels of methotrexate by microdialysis in muscle and solid tumor of the rabbit

PURPOSE

To determine of the pharmacokinetic profile of methotrexate (MTX) in blood and extracellular fluid (ECF) of VX2 tumor and muscle in rabbits.

METHODS

Microdialysis probes were inserted into VX2 tumor and in muscle tissue. Following intravenous administration of MTX (30 mg/kg), serial collection of arterial blood samples and dialysates of muscle and tumor ECF for 4 h was carried out. Quantitation of MTX and determination of free plasma concentrations was performed by fluorescence polarization immunoassay and ultrafiltration, respectively. Correlations were established between the unbound plasma and ECF MTX concentrations.

RESULTS

Total and free plasma concentrations exhibited a parallel three exponential decay in both healthy and tumorigenic animals. Total clearance (8.9 vs 6.5 ml-1.min-1.kg-1) and volume of distribution (4.0 vs 2.9 l.kg-1), however, tended to decrease in the tumor-bearing group. The ECF/plasma AUC ratio equaled 14.2 +/- 8.8% in muscle and 23.9 +/- 15.9% in tumor. The concentration-time profile of muscle ECF MTX was parallel and highly correlated (r = 0.97) to that determined in plasma. In contrast, free MTX plasma levels were not correlated with tumor ECF concentrations (r = 0.564).

CONCLUSIONS

In addition to the well-known pharmacological variability in the concentration-effect relationship, the important inter-individual variability in tumor exposure to MTX may partly explain that studies in patients with solid tumors have often failed to demonstrate firm correlations between MTX blood pharmacokinetics and the chemotherapeutic response.

[Cutaneous vasculitis: how to recognize, interpret, treat it?]

Clinical and histopathological features of cutaneous vasculitis are presented by means of 14 case reports. Proof of vasculitis in skin biopsy consecutively demands for a search of a cause and of the extension of the vasculitic process in the sense of a systemic disease. The most frequent form of cutaneous vasculitis is hypersensitivity angiitis, a disease in which always an exogenous (drugs, infections) or an endogenous (malignant neoplasia, connective tissue disease) trigger should be sought if cutaneous vasculitis persists after removal or treatment of the suspected cause. Then, antihistaminic or--particularly in cases with systemic involvement--immunosuppressive drugs (corticosteroids or cyclophosphamide) should be considered.

Compared plasma and brain pharmacokinetics of clomipramine and its metabolite demethylclomipramine in two strains of mice (NMRI and CD1)

The fate of clomipramine (CMI) and its main demethylated metabolite demethylclomipramine (DCMI) was studied in two strains of Swiss mice (NMRI and CD1) after intraperitoneal injection. A study of its distribution among various tissues showed that fixation was most marked in lungs, perirenal fat and kidneys, and only moderate in the brain. The pharmacokinetic parameters of both molecules were determined in brain tissue and plasma. Absorption was rapid (tmax CMI = 14 min), metabolism prompt (tmax DCMI = 17 or 18 min according to the breed) and elimination rapid from both plasma and brain tissue. The first two stages were similar in the two strains, but elimination of CMI from both plasma and brain was faster in the NMRI mice (plasma t1/2 = 53 min against 165 min in the CD1 mice). Both values were well below that reported for man (mean plasma t1/2 = 24 h). The data presented can serve as a basis for designing true chronic administration protocol in animals.

Comparative effects of different uptake inhibitor antidepressants in two pain tests in mice

The purpose of this study was to compare the analgesic effect of acute injections (1.25 and 20 mg/kg, ip) of several antidepressants with different effects on monoamine reuptake, on two pain tests in mice (hot-plate and phenylbenzoquinone-induced abdominal writhes). Serotonergic inhibitors (citalopram, fluvoxamine and clomipramine) were more effective in the hot-plate test whereas noradrenaline reuptake inhibitors (desipramine and maprotilline) were more effective in the writhing test. The mixed antidepressants (amitriptyline and to a lesser degree trimipramine) were more effective in the two tests than the other antidepressant drugs. Changes in motor activity of clomipramine and amitriptyline could not account for the modifications of pain threshold. Amineptine (a dopamine reuptake inhibitor) failed to induce any antinociceptive effect in the hot-plate test and was hyperalgesic in the writhing test, which could be explained by an increased motor activity. These findings indicate that the antinociceptive potency of reuptake inhibitors varies according to their monoamine specificity and the nature of stimuli. They would suggest that the preferential choice of serotonergic antidepressants in the management of chronic pain is arguable.

Antinociceptive activity of metapramine in mice. Relationship with its pharmacokinetic properties

The antinociceptive effect of acutely and chronically (every brain elimination half-life time) administered metapramine, a tricyclic antidepressant without anticholinergic or cardiotoxic effects, was studied in three different pain tests. In the hot plate test, its action was more potent when jumping was used as a pain parameter (acute ED50 = 19 +/- 3 mg/kg, i.p.) than when pain was assessed by licking of forepaws (only 20 mg/kg, i.p. was weakly active). Five chronic doses of 15 mg/kg were as active in the tail-flick test as an acute dose of 20 mg/kg (only active dose). Metapramine was more effective in the PBQ-induced writhing test after acute (ED50 = 9.9 +/- 0.1 mg/kg, i.p.) and chronic administration. A significant linear correlation was found between the effect in this test and plasma and overall brain levels of metapramine. No correlation was observed with levels of its three desmethylated metabolites. The usefullness of using a well-defined pattern of administration based on pharmacokinetic parameters and the involvement of monoaminergic mechanisms and of some metabolites of metapramine are discussed.

[Atypical giant cell arteritis]

The atypical clinical course of giant-cell arteritis in the elderly (who may develop a clinical picture of severe consumptive disease) is illustrated by two observations with histologically confirmed temporal arteritis. In addition to fever and loss of weight, the inflammatory vascular process in a 78-year old female was reflected in arrhythmias (atrial fibrillation and atrial flutter), probably due to involvement of the coronary arteries, and occlusion of the left axillary artery. Similar general symptoms and various neurological deficits comprising amaurosis, mononeuritis multiplex, polyneuropathy, myopathy and finally subarachnoid hemorrhage characterized the disease in a 72-year-old man. The picture was further complicated by intestinal perforation. In both patients steroids brought considerable improvement and the disease process came to a standstill.

[Salsolinol, an endogenous molecule. Possible implications in alcoholism, Parkinson's disease and pain]

Salsolinol can be formed either by condensation of dopamine with acetaldehyde, or by condensation of dopamine with pyruvic acid followed by decarboxylation. Salsolinol has a complex pharmacologic profile. Its opium-like activity may be related to alcohol dependency and to the effectiveness of naloxone during acute alcohol intoxication. Because they had noticed that alcoholism and Parkinson's disease rarely coexist, the authors undertook a study to confirm this fact and attempt to explain it by implicating salsolinol. Urinary excretion of salsolinol was found to increase following ingestion of alcohol, as well as in Parkinson patients under L-dopa treatment. The authors also found that urinary salsolinol was very low in untreated patients with Parkinson's disease. Salsolinol was detected in a number of foods and beverages. Separate assays of enantiomeres showed that the S enantiomere predominates in some foods whereas the R enantiomere is more abundant in humans. Lastly, the antinociceptive effects of salsolinol and its enantiomeres were studied in mice and antidepressant effects were evidenced using predictive tests.

Lack of importance of caffeine as an analgesic adjuvant of dipyrone in mice

The analgesic effect of caffeine used alone and in combination with dipyrone and butalbital was evaluated after oral administration in mice, using two different pain tests: the hot plate test and the phenylbenzoquinone-induced writhing test. Neither caffeine (5 to 200 mg/kg) nor butalbital (10 and 20 mg/kg) (20 mg/kg was the highest dose that did not induce sleep) produced a significant antinociceptive effect, whereas dipyrone was active from 400 mg/kg in the hot plate test and from 50 mg/kg in the writhing test. The scores obtained with the combinations were not different from those of the dipyrone-treated group, except for the butalbital-dipyrone combination. Thus caffeine is not an analgesic adjuvant in mice; its presence in the combination studied appears to be justifiable only insofar as it inhibited the sedative effect of butalbital.

Pharmacokinetic patterns of repeated administration of antidepressants in animals. II. Their relevance in a study of the influence of clomipramine on morphine analgesia in mice

Many studies have shown tricyclic antidepressants (TCAs) to potentiate morphine analgesia, but more recent work, using different modes of administration, has revealed inhibition of morphine analgesia by TCAs. The influence of different modes of administration of clomipramine (CMI) on morphine analgesia assessed by the hot-plate test was studied in mice. The administration procedure was based on the pharmacokinetic parameters of CMI determined in the strain used. Acute and chronic (i.e., every half-life of 130 min for five half-lives) administration of CMI (10 or 20 mg/kg i.p.) had opposite effects; the former potentiated morphine analgesia and the latter inhibited it. Five closely repeated administrations (i.e., every 40 min) suppressed the potentiation without producing inhibition. The time course of the influence of CMI showed that the inhibition of morphine analgesia observed after repeated administration of a given dose of CMI occurred if the latter was present for sufficient time; this time decreased when the dose of CMI was increased. Moreover, comparison with literature data shows the importance of standardized patterns of repeated administration: the variability in the frequency of repeated administration and in the time-lag between the last injection of TCA and the test may account for the varying results observed. The discrepancies in the literature regarding TCA/morphine interaction are thus only apparent, and arise merely from varying conditions. Possible mechanisms for the CMI-morphine interaction are discussed: involvement of opiate receptors and/or the serotonergic system.

Antinociceptive activity of salsolinol (racemate, R(+)-, S(-)-enantiomers): evidence of a peripheral mechanism

The existence and the characteristics of the antinociceptive action of salsolinol (racemate) and its two R(+)- and S(-)-enantiomers were studied using different pain tests in mice. None of these drugs possessed a significant activity on the tests sensitive to central acting analgesics (hot-plate and tail-flick tests), either after systemic (i.p.) or central (i.c.v.) injections. However, injected i.p., they reduced the number of writhes induced by phenylbenzoquinone; the ED50 was 79 +/- 2, 73 +/- 2 and 61 +/- 2 mg/kg for racemate, R(+)- and S(-)-enantiomer respectively. This activity was not antagonized by naloxone. Moreover, racemate and S(-) reduced, only for the highest used active dose on the PBQ test (128 mg/kg, i.p.), the edema induced by an intraplantar injection of carrageenin. These results provide evidence of an analgesic activity independent of the endogenous opiate systems and involving a peripheral mechanism.

Pharmacokinetic patterns of repeated administration of antidepressants in animals. I. Implications for antinociceptive action of clomipramine in mice

The pattern of repeated administration of antidepressants in animals varies from one study to another, making comparison of results difficult. We propose a means of standardizing the pattern of administration for any particular animal, based on a pharmacokinetic study of the antidepressant [here clomipramine (CMI)] in that animal. The plasma half-life (127 min) in the Swiss CD1 mouse was used as a basis for chronic administration, which was strictly every half-life as in clinical use. Daily administration is thus merely repeated acute administration. The antinociceptive action of CMI was compared under four sets of conditions of injection: single, chronic, daily and closely repeated (every 40 min). The antinociceptive effect obtained after an acute injection of CMI (10 or 20 mg/kg i.p.) was increased 2-fold after five chronic injections. Closely repeated injections gave a more marked effect than chronic administration, and daily administration was ineffective. The time course of the antinociceptive action correlated with that of blood and brain levels of CMI and its monodemethylated derivative. The enhancement of the antinociceptive action observed after chronic and closely repeated administration was shown not to be due to any modification of motor activity. It was suppressed by naloxone. Comparison with results reported in the literature shows the benefit of using a well-defined pattern of administration.

An automated method to analyze vocalization of unrestrained rats submitted to noxious electrical stimuli

Unrestrained rats were subjected to electrical stimuli applied to their paws via an electrified cage floor. Intensity, duration, and order of stimulation were chosen after preliminary tests. Vocalization threshold and vocalization as a behavioral response were studied. The vocalization was recorded and the signal analyzed by a simple computerized method that calculated five parameters: delay, maximal amplitude, duration, area, and maximal derivative with respect to time. The last four parameters increased with increasing intensity of stimulation and remained stable when the same stimulation was given repeatedly. Sensitivity to morphine (2.5 and 5 mg/kg s.c.) was tested. Morphine raised the threshold and lowered vocalization parameters, and it was antagonized by naloxone, thus validating the method. The sensitivity of the test and its capacity to separate sensory and affective components of pain are discussed.

[Effect of meteorologic and atmospheric health factors on acute diseases of the respiratory tract in children--as exemplified by the Biel region]

In the region of the small town of Biel, cases of various acute respiratory illnesses among children were recorded and correlated with measured parameters of meteorology and air pollution (sulfur dioxide, dust) during a period of one and a half years. An increase of cases was noted during the fall and winter months, by low temperatures, high humidity and meteorological conditions with northerly synoptic winds. Also the correlation of the cases to SO2 deposition values revealed a significant connection that may possibly be simulated by identical seasonal changes. No significant connection could be found between concentrations of SO2 respectively dust values and frequency of illness.

[Effect of meteorologic and air hygiene factors on acute respiratory tract diseases in children--based on the example of the Biel region]

In the area of a Swiss town (Biel) and its surroundings, cases of various acute respiratory illnesses among children were recorded and correlated with measured parameters of weather and air pollution (sulfur dioxide, dust) during a period of 17 months. An increase in cases was noted during the fall and winter months, involving low temperatures, high humidity and weather conditions with northerly synoptic winds. Also, correlation of the cases to SO2 deposition values revealed a significant connection that may possibly be simulated by identical seasonal changes. No significant connection could be found between concentrations of SO2 or dust values and frequency of illness.

[Pseudo-Bartter syndrome in diuretics abuse]

In a 45-year-old woman with chronic hypokalemia, clinical, chemical and endocrinological results pointed to Bartter's syndrome as cause of the disturbance. By screening the patient's urine twice, positive results for furosemide were obtained and we came to the conclusion, that the patient was suffering from Pseudo-Bartter's syndrome due to chronic abuse of diuretics.

[Pernicious anemia as cause of secondary sterility]

After starting treatment with vitamin B12, a 32-year-old woman with pernicious anaemia and secondary infertility became pregnant again and gave birth to a healthy child. It has been found that pernicious anaemia, which is rare during childbearing age, usually leads to infertility in men and women. This is reversible by treatment with vitamin B12.

[Drug side effects as the probable cause of death. Results of the Berne Comprehensive Hospital Drug Monitoring Program]

During the years 1974-1980, 19 of 17,285 inpatients of the divisions of internal medicine of two teaching hospitals showed a probable or definite adverse drug reaction (ADR) which was considered to be a major cause of death. In 7 patients the decisive ADR occurred during the hospital stay. The overall mortality from ADR is 0.040%. For each therapeutic group of drugs the following rate of drug-related death was calculated: for anticoagulants 0.047% (3/6378 inpatients), for cardiac glycosides 0.016% (1/6368), for analgesic/antirheumatic drugs 0.014% (1/7112) and for cytostatic drugs 0.38% (2/531). In 12 patients the ADR was already present on hospital admission.

[Transient neonatal macrocephaly. The differential diagnosis of abnormally fast-growing skull in newborn infants]

In a twin baby of low birth weight a transient abnormally increased growth velocity of the head circumference could be observed. Sodium and water retention were recognized as the underlying disturbance responsible for brain edema. This mechanism is one of several possible etiologic factors leading to macrocephaly in early infancy. Pathogenesis, therapy and prophylactic measures are discussed.