Drug-related admissions due to interaction with an old drug, lithium

Lithium is one of the oldest psychotropic drugs with a well-known narrow therapeutic range and the drugs that interact with lithium elimination are well established. However, patients are still admitted to the emergency department with lithium toxicity due to often overlooked interactions with concomitant drugs. We report on two patients, admitted to the emergency department, with lithium toxicity. One patient presented with aphasia and ataxia, showing moderate toxicity. The other was referred due to coma, illustrating severe lithium toxicity. In both cases, a non-steroidal anti-inflammatory drug was the underlying cause. We highlight the mechanism of this drug-drug interaction and underline the need for thoughtful use of other medications in patients taking lithium. Special attention has to be paid for the non-steroidal antiinflammatory drugs due to the low threshold of prescribing them for the control of acute pain and its availability as free over-the-counter drugs.

Identification of microRNA-based signatures for response and survival for non-small cell lung cancer treated with cisplatin-vinorelbine A ELCWP prospective study

Clinical variables, like stage and performance status (PS), have predictive and prognostic values in advanced non-small cell lung cancer (NSCLC) patients treated with chemotherapy, not allowing adequate individual prediction. MicroRNA (miRNA) are non-coding RNAs regulating gene expression. In a prospective study, we assessed the predictive value for response and survival of tumour miRNA in NSCLC patients treated by 1st line cisplatin and vinorelbine. miRNA expression was analysed on a biopsy obtained during the diagnostic bronchoscopy, using TaqMan Low Density Arrays. The signature for response was derived using logistic regression with stepwise variable selection. The associations between overall survival and miRNA expression levels were estimated by using the Kaplan-Meier method, log-rank test, and Cox proportional hazard regression models to estimate the hazard ratios. In total, 38 patients with adequate tumour biopsies, treated with cisplatin-vinorelbine were included: male (n = 27), 80-100 Karnofsky PS (n = 27), adenocarcinoma (n = 20), stage IV (n = 30). One patient was considered not assessable for response but remained included in the survival analyses. Out of the 37 patients assessable for response, 16 partial responses (43%) were observed. A two miRNA signature (miR-149 and miR-375) was found predictive for response and was also associated to progression-free survival (p = 0.05). Using a linear combination of the miR CT values with Cox's regression coefficients as weights, we constructed a prognostic score for overall survival including four miRNA (miR-200c, miR-424, miR-29c and miR-124). The signature distinguished patients with good (n = 18) and poor (n = 20) prognosis with respective median survival times of 47.3 months (95% CI 29.8-52.4) and 15.5 months (95% CI 9.1-22.8) (p < 0.001; hazard ratio 21.1, 95% CI 4.7-94.9).

CONCLUSIONS

miRNA signature allows predicting response and is of prognostic value for survival in patients with NSCLC treated with first line cisplatin and vinorelbine.

Stimulation of the i.v. to oral switch of bioavailable drugs by phone calls in a Belgian tertiary care hospital

INTRODUCTION

Early switch from intravenous to oral administration of drugs with an almost complete oral bioavailability, can have important benefits. Drugs with almost complete bioavailability, like clindamycin (Dalacin), levofloxacin (Tavanic) and paracetamol (Perfusalgan/Dafalgan), are very suitable for an early intravenous to oral switch in patients whose gastrointestinal absorption is intact. The aim of this study was to investigate the impact of direct phone contact between pharmacist and clinician on the intravenous to oral switch and to evaluate the reasons, mentioned by clinicians, that prevented an early switch.

MATERIALS & METHODS

The project was initiated in a Belgian 1900-bed tertiary care hospital with a poster, communicated through the hospital's intranet and spread to every hospital ward. During one month, all prescriptions for intravenous clindamycin, levofloxacin and paracetamol were evaluated. The treating clinician was contacted by phone to evaluate if an intravenous to oral switch was possible.

RESULTS

Clinicians were contacted concerning 377 patients. For 58.7% of patients, the switch from intravenous to oral administration was made. In case of refusal, several reasons were mentioned by the clinician, some more appropriate than others.

CONCLUSION

Despite several appropriate reasons preventing an early intravenous to oral switch, there are still some aberrant opinions circulating in the hospital environment. Active interventions of pharmacists to stimulate intravenous to oral switch, using phone contact with the treating clinicians, can possibly be an adequate technique to stimulate intravenous to oral switch, but this needs to be further optimized.

Concomitant oral tyrosine kinase inhibitors and bisphosphonates in advanced renal cell carcinoma with bone metastases

BACKGROUND

The presence of bone metastases in patients with metastatic renal cell carcinoma treated with oral tyrosine kinase inhibitors (TKIs) is associated with poorer outcome as compared with patients without bone involvement. Concomitant bisphosphonates could probably improve outcomes but also induce osteonecrosis of the jaw (ONJ).

METHODS

Retrospective study on all the renal cell carcinoma patients with bone metastases treated with sunitinib or sorafenib between November 2005 and June 2012 at the University Hospitals Leuven and AZ Groeninge in Kortrijk.

RESULTS

Seventy-six patients were included in the outcome analysis: 49 treated with concomitant bisphosphonates, 27 with TKI alone. Both groups were well balanced in terms of prognostic and predictive markers. Response rate (38% vs 16% partial responses, P=0.028), median progression-free survival (7.0 vs 4.0 months, P=0.0011) and median overall survival (17.0 vs 7.0 months, P=0.022) were significantly better in patients receiving bisphosphonates. The incidence of ONJ was 10% in patients treated with TKI and bisphosphonates.

CONCLUSION

Concomitant use of bisphosphonates and TKI in renal cell carcinoma patients with bone involvement probably improves treatment efficacy, to be confirmed by prospective studies, but is associated with a high incidence of ONJ.

Calcium and phosphorus retention in the preterm infant during total parenteral nutrition. A comparative randomised study between organic and inorganic phosphate as a source of phosphorus

The preterm infant fed parenterally is prone to some demineralisation due in part to insufficient Calcium (Ca) and Phosphorus (P) retention. In an attempt to augment Ca and P retention, we prepared a standardised parenteral solution containing calcium gluconate and glucose-1-phosphate (Phocytan) as source of phosphorus, yielding a daily supply of 75 mg/kg Ca and 45 mg/kg P. 28 very low birthweight infants were randomly assigned to receive either this solution (high Ca P ; n = 15) or a conventional formulation containing calcium gluconate and potassium mono- and dibasic phosphate delivering 42 mg/kg Ca and 36 mg/kg P daily (low Ca P ; n = 13). In the high Ca P daily retention was respectively 80% and 99% for Ca and P whereas in the low Ca P group, retention was 70% and 82%. Serum parathormone levels were significantly lower in the high Ca P group. We conclude that parenteral nutrition with a new high Ca P supplement results in an augmented Ca and P retention in very low birthweight infants. This may help to prevent neonatal bone demineralization.

Selecting an appropriate and reimbursed anti-osteoporotic treatment option: a practical tool in the Belgian setting

Osteoporosis is a highly prevalent and often undertreated disease in the elderly. Osteoporosis-related fractures are associated with significant morbidity and mortality. Anti-osteoporotic drugs are only reimbursed by the Belgian government if strict conditions are fulfilled. The aim of this paper was to create a practical tool to guide the physician and other health care professionals to make an appropriate choice. Two flowcharts, based on Belgian reimbursement criteria and literature review were developed. Both tools provide an overview of the reimbursed pharmacological agents in the management of osteoporosis in male and female subjects.

Clostridium difficile infection after allogeneic hematopoietic stem cell transplantation: incidence, risk factors, and outcome

Clostridium difficile (C. difficile) infection was observed in 13% of recipients after hematopoietic stem cell transplantation (HSCT), mainly in the first month posttransplantation. Risk factors were cord blood as the source of stem cells, acute graft-versus-host disease (GVHD), and total body irradiation (TBI). No association was found with an increased risk of mortality. The purpose of this study was to evaluate the incidence, risk factors, and outcome of C. difficile infection (CDI) after HSCT. We conducted a single-center, retrospective, cohort study on all patients who received an allogeneic HSCT from January 2004 to December 2007. All patients with diarrhea in the first year after HSCT were tested for the presence of C. difficile in stools. Among the 407 assessable patients, 53 presented at least 1 CDI in the first year post-HSCT. The total incidence rate was 5.6 cases of CDI per 10,000 patient-days. Fifty percent of cases were diagnosed in the first month after HSCT, and 95% occurred during the first 6 months. Fewer than 5% of patients with CDI had severe diarrhea and severe complications were never observed. TBI in the conditioning regimen, cord blood as the source of stem cells, and acute graft-versus-host disease (aGVHD) were independently associated with CDI. Six patients (11%) had a recurrence of CDI. Four patients required second-line treatment with vancomycin. With a median follow-up of 22 months, the 2-year overall survival rates were similar between patients who presented a CDI and those who did not. CDI was observed in approximately 13% of recipients after HSCT, mainly in the first month posttransplantation and was associated with CB, aGVHD, and TBI. CDI was not associated either with severe complications or with an increased risk of mortality in this large cohort of patients.

Dual inhibition of PI3K and mTORC1/2 signaling by NVP-BEZ235 as a new therapeutic strategy for acute myeloid leukemia

PURPOSE

The growth and survival of acute myeloid leukemia (AML) cells are enhanced by the deregulation of signaling pathways such as phosphoinositide 3-kinase (PI3K)/Akt and mammalian target of rapamycin (mTOR). Major efforts have thus been made to develop molecules targeting these activated pathways. The mTOR serine/threonine kinase belongs to two separate complexes: mTORC1 and mTORC2. The mTORC1 pathway is rapamycin sensitive and controls protein translation through the phosphorylation of 4E-BP1 in most models. In AML, however, the translation process is deregulated and rapamycin resistant. Furthermore, the activity of PI3K/Akt and mTOR is closely related, as mTORC2 activates the oncogenic kinase Akt. We therefore tested, in this study, the antileukemic activity of the dual PI3K/mTOR ATP-competitive inhibitor NVP-BEZ235 compound (Novartis).

EXPERIMENTAL DESIGN

The activity of NVP-BEZ235 was tested in primary AML samples (n = 21) and human leukemic cell lines. The different signaling pathways were analyzed by Western blotting. The cap-dependent mRNA translation was studied by 7-methyl-GTP pull-down experiments, polysomal analysis, and [(3)H]leucine incorporation assays. The antileukemic activity of NVP-BEZ235 was tested by analyzing its effects on leukemic progenitor clonogenicity, blast cell proliferation, and survival.

RESULTS

The NVP-BEZ235 compound was found to inhibit PI3K and mTORC1 signaling and also mTORC2 activity. Furthermore, NVP-BEZ235 fully inhibits the rapamycin-resistant phosphorylation of 4E-BP1, resulting in a marked inhibition of protein translation in AML cells. Hence, NVP-BEZ235 reduces the proliferation rate and induces an important apoptotic response in AML cells without affecting normal CD34(+) survival.

CONCLUSIONS

Our results clearly show the antileukemic efficiency of the NVP-BEZ235 compound, which therefore represents a promising option for future AML therapies.

Perspectives on inhibiting mTOR as a future treatment strategy for hematological malignancies

Mammalian target of rapamycin (mTOR) is a protein kinase implicated in the regulation of various cellular processes, including those required for tumor development, such as the initiation of mRNA translation, cell-cycle progression and cellular proliferation. In a wide range of hematological malignancies, the mTORC1 signaling pathway has been found to be deregulated and has been designed as a major target for tumor therapy. Given that pre-clinical studies have clearly established the therapeutic value of mTORC1 inhibition, numerous clinical trials of rapamycin and its derivates (rapalogs) are ongoing for treatment of these diseases. At this time, although disease stabilization and tumor regression have been observed, objective responses in some tumor types have been modest. Nevertheless, some of the mechanisms underlying cancer-cell resistance to rapamycin have now been described, thereby leading to the development of new strategy to efficiently target mTOR signaling in these diseases. In this review, we discuss the rationale for using mTOR inhibitors as novel therapies for a variety of hematological, malignancies with a focus on promising new perspectives for these approaches.

Skin Microvascular Thrombosis in Fusarium Infection in Two Early Biopsied Cases

Fusarium species cause rare and severe infections. Their incidence is increasing in immunocompromised patients but they are also observed in healthy hosts. Because of the rapid dissemination of infection and the frequent resistance of Fusarium species to antifungal drugs, histopathologic evidence of hyphae is very helpful to obtain the diagnosis rapidly. We report the clinical and pathological features of two patients with initial cutaneous lesions. Cutaneous early biopsies showed microvessel involvement with hyphae and thrombosis. Fusarium infection was confirmed by skin culture. Hyphae within a microvessel thrombus in the skin were highly suggestive of disseminated fungal infection. These pathological features enabled to establish an early diagnosis and to start efficient antifungal treatment. In early cutaneous biopsies of immunocompromised patients, the presence of cutaneous vessel thrombosis can suggest a fungal infection and may help to start specific therapy without delay for these life-threatening infections.

Autocrine IGF-1/IGF-1R signaling is responsible for constitutive PI3K/Akt activation in acute myeloid leukemia: therapeutic value of neutralizing anti-IGF-1R antibody

BACKGROUND

Alterations in the PI3K/Akt pathway are found in a wide range of cancers and the development of PI3K inhibitors represents a promising approach to cancer therapy. Constitutive PI3K activation, reflecting an intrinsic oncogenic deregulation of primary blast cells, is detected in 50% of patients with acute myeloid leukemia. However, the mechanisms leading to this activation are currently unknown. As we previously reported IGF-1 autocriny in acute myeloid leukemia cells, we investigated whether IGF-1 signaling was involved in the constitutive activation of PI3K.

DESIGN AND METHODS

We analyzed the IGF-1/IGF-1R signaling pathway and PI3K activity in 40 acute myeloid leukemia bone marrow samples. Specific inhibition of IGF-1/IGF-1R signaling was investigated using neutralizing anti-IGF-1R, anti-IGF-1 antibodies or IGF-1 short interfering RNA. The anti-leukemic activity of the neutralizing anti-IGF-1R was tested by analyzing its effects on leukemic progenitor clonogenicity, blast cell proliferation and survival.

RESULTS

In all samples tested, we found that functional IGF-1R was constantly expressed in leukemic cells. In the acute myeloid leukemia samples with PI3K activation, we found that the IGF-1R was constitutively phosphorylated, although no IGF-1R activating mutation was detected. Specific inhibition of IGF-1R signaling with neutralizing anti-IGF-1R strongly inhibited the constitutive phosphorylation of both IGF-1R and Akt in 70% of the PI3K activated samples. Moreover, both incubation with anti-IGF-1 antibody and IGF-1 short interfering RNA inhibited Akt phosphorylation in leukemic cells. Finally, neutralizing anti-IGF-1R treatment decreased the clonogenicity of leukemic progenitors and the proliferation of PI3K activated acute myeloid leukemia cells.

CONCLUSIONS

Our current data indicate a critical role for IGF-1 autocriny in constitutive PI3K/Akt activation in primary acute myeloid leukemia cells and provide a strong rationale for targeting IGF-1R as a potential new therapy for this disease.

Role of the PI3K/AKT and mTOR signaling pathways in acute myeloid leukemia

The PI3K/AKT and mTOR signaling pathways are activated in acute myeloid leukemia, including in the more immature leukemic populations. Constitutive PI3K activation is detectable in 50% of acute myeloid leukemia samples whereas mTORC1 is activated in all cases of this disease. In leukemic cells, the PI3K activity relates to the expression of the p110delta isoform of class IA PI3K. Constitutive PI3K activation is the result of autocrine IGF-1/IGF-1R signaling in 70% of acute myeloid leukemia samples but specific inhibition of this pathway does not induce apoptosis. Specific inhibition of PI3K/AKT or mTORC1 alone in vitro has anti-leukemic effects which are essentially exerted via the suppression of proliferation. However, as mTORC1 activation is independent of PI3K/AKT in acute myeloid leukemia, dual PI3K and mTOR inhibitors may induce apoptosis in blast cells. Moreover, mTORC1 inhibition using sirolimus overactivates PI3K/AKT via the upregulation of IRS2 expression and by favoring IGF-1/IGF-1R autocrine signaling. Recent data also indicate that mTORC1 does not control protein translation in acute myeloid leukemia. These results open the way for the design of direct inhibitors of protein synthesis as novel acute myeloid leukemia therapies and also for the development of second generation mTOR inhibitors (the TORKinhibs).