The usefulness of Olanzapine plasma concentrations in monitoring treatment efficacy and metabolic disturbances in first-episode psychosis

INTRODUCTION

The role of Olanzapine therapeutic drug monitoring is controversial. The present study explores the associations of Olanzapine plasma concentrations with clinical response and metabolic side effects in first episode psychosis (FEP) after 2 months of treatment.

METHODS

Forty-seven patients were included. Improvement in clinical symptomatology was assessed using the PANSS. Metabolic assessment included weight, blood pressure, waist circumference, blood glucose, total cholesterol, high-density lipoprotein, low-density lipoprotein, and triglycerides.

RESULTS

The Olanzapine plasma concentrations after 2 months of treatment were positively correlated with weight gain (r = 0.49, p = 0.003), and a concentration > 23.28 ng/mL was identified as a positive predictor of weight gain (≥ 7%). The Olanzapine concentration to dose (C/D) ratio was positively correlated with the percentage of improvement in the total PANSS (r = 0.46, p = 0.004), and a C/D ratio > 2.12 was identified as a positive predictor of a good response (percentage of improvement > 30%) after 2 months of treatment. We also identified several factors that could alter Olanzapine pharmacokinetics: gender (p = 0.03), diagnosis (p = 0.05), smoking habit (p = 0.05), and co-medications such as valproic acid (p = 0.05) and anxiolytics (p = 0.01).

DISCUSSION

In conclusion, our results suggest that therapeutic drug monitoring of Olanzapine could be helpful to evaluate therapeutic efficacy and metabolic dysfunction in FEP patients treated with Olanzapine.

Tenofovir disoproxil fumarate/emtricitabine plus ritonavir-boosted lopinavir or cobicistat-boosted elvitegravir as a single-tablet regimen for HIV post-exposure prophylaxis

Objectives

To assess HIV-1 post-exposure prophylaxis (PEP) non-completion at day 28, comparing ritonavir-boosted lopinavir versus cobicistat-boosted elvitegravir as a single-tablet regimen (STR), using tenofovir disoproxil fumarate/emtricitabine with both of these therapies.

Methods

A prospective, open, randomized clinical trial was performed. Individuals attending the emergency room due to potential sexual exposure to HIV and who met criteria for PEP were randomized 1:3 into two groups receiving either 400/100 mg of lopinavir/ritonavir (n = 38) or 150/150 mg of elvitegravir/cobicistat (n = 119), with both groups also receiving 245/200 mg of tenofovir disoproxil fumarate/emtricitabine. Five follow-up visits were scheduled at days 1, 10, 28, 90 and 180. The primary endpoint was PEP non-completion at day 28. Secondary endpoints were adherence, adverse effects and rate of seroconversions. Clinical trials.gov number: NCT08431173.

Results

Median age was 32 years and 95% were males. PEP non-completion at day 28 was 36% (n = 57), with a trend to be higher in the lopinavir/ritonavir arm [lopinavir/ritonavir 47% (n = 18) versus elvitegravir/cobicistat 33% (n = 39), P = 0.10]. We performed a modified ITT analysis including only those patients who attended on day 1. PEP non-completion in this subgroup was higher in the lopinavir/ritonavir arm than in the elvitegravir/cobicistat arm (33% versus 15%, respectively, P = 0.04). Poor adherence was significantly higher in the lopinavir/ritonavir arm versus the elvitegravir/cobicistat arm (47% versus 9%, respectively, P < 0.0001). Adverse events were reported by 73 patients (59%), and were significantly more common in the lopinavir/ritonavir arm (90% versus 49%, P = 0.0001). A seroconversion was observed in the elvitegravir/cobicistat arm in a patient with multiple exposures before and after PEP.

Conclusions

A higher PEP non-completion, poor adherence and adverse events were observed in patients allocated to the lopinavir/ritonavir arm, suggesting that STR elvitegravir/cobicistat is a well-tolerated antiretroviral for PEP.

A randomized trial comparing the efficacy and tolerability of two HAART strategies at two years in antiretroviral naive patients

BACKGROUND

The use of HAART combining 2 nucleoside analogues reverse transcriptase inhibitors (NRTIs) plus one protease inhibitor (PI) or 2 NRTIs + 1 non-nucleoside reverse transcriptase inhibitor (NNRTI) has shown comparable efficacy. The study was designed to compare long term (2 years) effectiveness of two antiretroviral (ARV) treatment strategies in patients not previously treated: starting with a nelfinavir based HAART switching to nevirapine in case of failure or side effects or the reverse sequence.

METHODS

This multicenter, randomized, open label clinical trial enrolled ARV-naïve HIV patients with CD4 counts below 500 cells/mm3. They were randomly assigned to start ddI + d4T + nelfinavir (switching to ZDV + 3TC + NEV in case of failure or toxicity) (PI-NEV arm) or ddI + d4T + nevirapine, switching to ZDV + 3TC + NFV in case of failure or toxicity (NEV-PI arm). The primary study endpoint was the Kaplan-Meier estimates of the time to failure after switching to second regimen if necessary (considering failure as two consecutive plasma HIV-1 RNA determinations above 200 copies/mL, death, a new category C event or toxicity leading to treatment discontinuation of the second regimen) after a minimum follow-up of two years.

RESULTS

A total of 137 patients were evaluable (67 and 70 in the PI-NEV and NEV-PI arms respectively). Baseline characteristics did not differ among groups. Kaplan-Meier estimates of time to failure did not show differences between the two arms neither in the on-treatment (OT) analysis (log rank test, p = 0.81) nor in the intent-to-treat (ITT) analysis (p = 0.58). At 24 months, the estimated proportion of patients free of failure were 72% and 66% respectively in the PI-NEV and NEV-PI arms OT analysis (p = 0.54) and 73% and 64% in the PI-NEV and NEV-PI arms in the ITT analysis (p = 0.49). The difference in the median in CD4+ lymphocyte count at 24 months was not significantly different in the two groups: 393 and 307 CD4 cells/mm3 in the PI-NEV and NEV-PI arms respectively (p = 0.167). The incidence of adverse events (AEs) in the two arms was very similar: 50 (75%) in the PI-NEV and 54 (70%) in the NEV-PI group, as it was for grade 3-4 AEs leading to drug switching.

CONCLUSION

At two years both treatments strategies (PI-NEV vs NEV-PI) had a high and comparable efficacy and were generally well tolerated.

Hepatotoxicity in HIV-1-infected patients receiving nevirapine-containing antiretroviral therapy

OBJECTIVES

To assess the incidence and risk factors for hepatotoxicity associated with nevirapine.

DESIGN

A prospective cohort study in a teaching and referral hospital involving all consecutive patients who were prescribed a nevirapine-containing antiretroviral regimen between September 1997 and May 2000.

METHOD

Cutaneous and hepatic adverse reactions and clinical hepatitis were assessed. Blood analysis including plasma HIV-1 RNA CD4 cell counts, liver chemistry tests, and serology for hepatitis B and C viruses. Hepatotoxicity was defined as an increase of at least threefold in serum alanine aminotransferase or aspartate aminotransferase levels compared with baseline values.

RESULTS

Of a total of 610 patients, 82 (13.4%) were antiretroviral naive when commencing nevirapine, and 46.2 and 8.9% were coinfected with hepatitis C and B viruses, respectively. Median duration of exposure to nevirapine was 8.7 months (interquartile range 3.4--14.3). Hepatotoxicity developed in 76 (12.5%), an incidence of 13.1/100 person-years. Kaplan--Meier estimated incidence of hepatotoxicity at 3, 6 and 12 months was 3.7, 9.7 and 20.1%, respectively. In seven (1.1%) patients, hepatotoxicity was associated with clinical hepatitis, which was reversible upon discontinuation of therapy. Multivariate analysis identified the duration of prior exposure to antiretroviral drugs, hepatitis C virus, and higher baseline levels of alanine aminotransferase as independent risk factors for hepatotoxicity.

CONCLUSIONS

Hepatotoxicity but not clinical hepatitis was common in HIV-1-infected patients receiving nevirapine-containing regimens and the incidence steadily increased over time. Prolonged exposure to any antiretroviral therapy, coinfection with hepatitis C virus and abnormal baseline levels of alanine aminotransferase identified patients at a higher risk.

The use of evidence in pharmacovigilance

OBJECTIVE

Withdrawal of a drug from the market for safety reasons is a serious and sometimes complex decision. The scientific evidence supporting drug withdrawals in the past years is critically appraised.

METHODS

With data provided by the Spanish Medicines Agency, all drugs withdrawn from the Spanish market for safety reasons from January 1990 to December 1999 were identified. The adverse drug reactions (ADRs) were classified by the year of withdrawal, by the organ/system affected and by the alleged type of reaction (Rawlins and Thompson classification). A systematic review of the literature was performed.

RESULTS

A total of 22 drugs were withdrawn from the market due to safety reasons. In 18 of 22 cases (82%), the evidence supporting the drug withdrawal came from individual case reports, cases series or the combination of data provided by randomised clinical trials and case reports. Hepatic (eight cases) and cardiac (five cases) reactions accounted for 59% (13 of 22) of the total withdrawals. In 10 of 22 (45%) cases, drug withdrawal was clearly due to type-B reactions. Only four withdrawals were based on evidence from observational studies including a comparison group.

CONCLUSION

Case reports are the main source of information used to withdraw a drug from the market for safety reasons. It is necessary to improve the quality of evidence supporting the withdrawal process of drugs linked to unexpected and severe ADRs. The use of large databases to perform cohort or nested case-control analyses is the most efficient and reliable method to study type-A class effect ADRs. The implementation of such databases in different countries could increase the quality of the information on ADRs by allowing researchers to conduct efficiently these type of studies.

Dose-finding study of once-daily indinavir/ritonavir plus zidovudine and lamivudine in HIV-infected patients

BACKGROUND

Strategies for treatment of HIV need to be considered in terms of combining potency, safety, and convenience of dosage. However, regimens including once-daily protease inhibitors are not yet available. We have performed a pilot study to determine an indinavir/ritonavir (IND/RTV) regimen for once-daily dosing, by monitoring plasma levels.

METHODS

Antiretroviral-naive HIV-infected adults were eligible. Therapy was zidovudine/lamivudine 1 pill twice daily plus IND/RIT (liquid formulation) 800/100 mg twice daily with food. At 4-week intervals, plasma levels were measured and dosage of IND/RIT switched to 1000/100 mg daily and then 800/200 mg daily. If 12-hour minimum concentrations (Cmin12h) of IND were too low (<0.1 microg/ml) with IND/RIT 1000/100 mg once daily in the first half of the patients, it was planned to switch directly to 800/200 mg once daily in the other half.

RESULTS

In all, 27 patients were recruited. Mean baseline CD4+ lymphocyte count was 107 x 106/L (range, 4-623 x 106/L). Eleven patients (40%) discontinued the study medication within the first 4 weeks due to clinical progression (n = 3) or grade 1-2 RTV related side effects (n = 8). Nine patients (group A) switched from 800/100 mg twice daily to 1000/100 mg once daily and then to 800/200 mg once daily. Seven patients (group B) switched directly to 800/200 mg once daily. At week 32, viral load was <5 copies/ml in 15 of 16 patients (94%). RTV levels were always <2.1 microg/ml. The mean and 95% confidence interval for IND Cmin and Cmax in microg/ml was: using IND/RTV 800/100 mg twice daily (n = 16) 1.4 (0.5-2.3) and 6.7 (4.4-9.1), respectively; using IND/RTV 1000/100 mg once daily (n = 9) 0.18 (0-0.41) and 8.6 (3.3-14), respectively; and using 800/200 mg once daily (n = 16) 0.38 (0-0.9), and 7.5 (0.8-14.8). For all 16 patients who received IND/RTV 800/100 mg twice daily, the Cmin value for IND was >/=0.1 microg/ml. Conversely, IND Cmin was <0.1 microg/ml in 4 of 9 receiving 1000/100 mg once daily but in only 1 of 16 receiving 800/200 mg once daily.

CONCLUSION

Once-daily regimen of IND/RIT is feasible and deserves further evaluation in larger randomized trials. Liquid formulation of RIT was not well tolerated by our antiretroviral-naive patients despite lower than suggested doses.

Methodological and political issues in clinical pharmacology research by the year 2000

Parallel groups in a large, multicenter, phase III "pivotal" randomized clinical trial (RCT) with clinically relevant end-points are seen by the medical community as the "gold standard" of clinical research. However, there are limitations, some methodological and others political. The main one is the external validity of the method because a treatment, as studied in RCTs, does not necessarily reflect how it is used in clinical practice. Also, the method, as it stands, is not really predictive of the success in a particular patient of a certain intervention studied in a trial. To overcome these methodological drawbacks, different options have been implemented. The most important ones are: (1) the performance of pragmatic RCTs intended to address effectiveness rather than efficacy; (2) meta-analysis; and (3) the use of observational studies, with or without a comparison group. Recent experience has shown that type-A adverse drug reactions (ADRs) related to a specific class of drugs have been successfully characterized throughout cohort- or population-based case-control studies, whereas the evidence linking a specific drug entity to a type-B ADR, apparently severe enough to withdraw the drug from the market, has come mainly from case reports or case series. Other limitations of the RCT are more of a political nature. These large "pivotal" trials are mostly sponsored by the pharmaceutical industry, and to guarantee the scientific and ethical integrity of data produced, they are performed following standard operating procedures (SOPs) and good clinical practice (GCP) guidelines. Sometimes industry is not interested in sponsoring trials; thus, RCTs performed are in practice highly biased because of their potential economical profits. Furthermore, applying SOPs and GCPs is expensive and difficult to implement, and it is hard to find funding in public institutions. As a result, there is an urgent need to create a network of independent, skilled groups interested in sponsoring and performing institutional RCTs following "user friendly" GCP when the profits are low, but scientific interest high.

Topical heparin for the treatment of acute superficial phlebitis secondary to indwelling intravenous catheter. A double-blind, randomized, placebo-controlled trial

OBJECTIVE

To assess the clinical efficacy of a topical gel containing 1000 IU x g(-1) of heparin, applied three times daily for a maximal period of 7 days to patients with acute superficial phlebitis secondary to indwelling intravenous catheter.

METHODS

A Double-blind, randomized, placebo-controlled study was conducted in one of the internal medicine wards of a tertiary General Hospital in Barcelona, Spain. Inpatients of both genders over 18 years of age that developed superficial phlebitis and gave informed consent were included in the study. The sample size estimation was 132 patients. Sixty-six patients were allocated to each group. There were five protocol deviations and 24 withdrawals in the intervention group, and one protocol deviation and 25 withdrawals in the control group. Consequently, 37 patients in the intervention group and 40 in the control group completed the trial. The main outcome measure was the disappearance of the symptoms and signs of superficial phlebitis. Clinical course, investigator's global impression and adverse events were also recorded.

RESULTS

According to the intention-to-treat analysis, after treatment for 7 days superficial phlebitis healed in 27 of the 61 patients (44.3%) who received topical heparin, and in 17 of the 65 patients (26.1%) receiving placebo, giving a relative risk [95% confidence interval (CI)] of 1.69 (1.03-2.78). This indicates that six patients (95% CI, 3-72) have to be treated in order to induce one additional healing. The clinical course and the overall clinical impression were similar in both groups. One patient treated with topical heparin developed mild urticaria.

CONCLUSION

Topical heparin is safe and effective for the treatment of superficial phlebitis secondary to indwelling intravenous catheter.

[Omeprazole: a new treatment for paranasal sinus polyps in Widal syndrome. Preliminary study]

A preliminary report is made of the potential therapeutic effect of omeprazol in reducing nasosinusal polyps. This study is based on the empirical observation of nasal airflow improvement in patients suffering from nasosinusal polyposis after administering omeprazol. Different phases of the study suggested that patients with Widal's syndrome benefited the most. Based on the results of this study, we have undertaken a randomized, parallel, double-blind, placebo-controlled clinical trial.