Pharmacokinetic changes in drugs during protein-calorie malnutrition: correlation between drug metabolism and hepatic microsomal cytochrome p450 isozymes

Air pollution induces morpho-functional, biochemical and biomechanical vascular dysfunction in undernourished rats

Air pollution (gases and particulate matter -PM) and child undernutrition are globally recognized stressors with significant consequences. PM and its components breach the respiratory alveolar-capillary barrier, entering the vasculature transporting not only harmful particles and its mediators but, altering vascular paracrine and autocrine functions. The aim of this study was to investigate the effects of Residual Oil Fly Ash (ROFA), on the vasculature of young animals with nutritional growth retardation (NGR). Weanling rats were fed a diet restricted 20% (NGR) compared to ad libitum intake (control-C) for 4 weeks. Rats were intranasally instilled with 1 mg/kg BW of ROFA. After 24h exposure, histological and immunohistochemical, biochemical and contractile response to NA/ACh were evaluated in aortas. ROFA induced changes in the tunica media of the aorta in all groups regarding thickness, muscular cells and expression of Connexin-43. ROFA increased TGF-β1 and decreased eNOs levels and calcium channels in C and NGR animals. An increment in cytokines IL-6 and IL-10 was observed in C, with no changes in NGR. ROFA exposure altered the vascular contractile capacity. In conclusion, ROFA exposure could increase the risk for CVD through the alteration of vascular biochemical parameters, a possible step of the endothelial dysfunction.

The role of nutrition in children with cancer

In recent years, the influence of nutrition on the health and growth of children has become increasingly important. The relevance of nutrition is even greater for children who are facing cancer. Malnutrition, within the context of undernutrition and overnutrition, may impact not only the effectiveness of treatments and outcomes, but also the quality of life for patients and their families. In this article, we review nutritional assessment methods for children with cancer, focusing on the specific characteristics of this population and analyze the efficacy of nutritional interventions, which include enteral, parenteral, and nutritional education. From our analysis, two important conclusions emerged: i) there is a need to focus our attention on the nutritional status and the body composition of oncologic children, since these factors have a relevant impact on clinical outcomes during treatment as well as after their conclusion; ii) the support of skilled clinical nutrition personnel would be extremely helpful for the global management of these patients.

Review of nutritional status, body composition, and effects of antineoplastic drug disposition

The overall survival for children with cancer in high income countries is excellent. However, there are many disparities that may negatively affect survival, which are particularly problematic in low income countries, such as nutritional status at diagnosis and throughout therapy. Nutritional status as well as concomitant foods, supplements, and medications may play a role in overall exposure and response to chemotherapy. Emerging science around the microbiome may also play a role and should be further explored as a contributor to disease progression and therapeutic response. This article highlights some of these issues and proposes additional areas of research relevant to nutritional status and pharmacology that are needed in pediatric oncology.

The relevance of nutrition to pediatric oncology: A cancer control perspective

It is indisputable that adequate and appropriate nutrition is fundamental to the health, growth, and development of infants, children, and adolescents, including those with cancer. Nutrition has a role in most of the accepted components of the cancer control spectrum, from prevention through to palliation. The science of nutrigenomics, nutrigenetics, and bioactive foods (phytochemicals), and how nutrition affects cancer biology and cancer treatment, is growing. Nutritional epigenetics is giving us an understanding that there are possible primary prevention strategies for pediatric cancers, especially during conception and pregnancy, which need to be studied. Primary prevention of cancer in adults, such as colorectal cancer, should commence early in childhood, given the long gestation of nutritionally related cancers. Obesity avoidance is definitely a target for both pediatric and adult cancer prevention, commencing in childhood. There is now compelling evidence that the nutritional status of children with cancer, both overweight and underweight, does affect cancer outcomes. This is a potentially modifiable prognostic factor. Consistent longitudinal nutritional assessment of patients from diagnosis through treatment and long-term follow-up is required so that interventions can be implemented and evaluated. While improving, there remains a dearth of basic and clinical nutritional research in pediatric oncology. The perspective of evaluating nutrition as a cancer control factor is discussed in this article.

Reducing Undernutrition through Counseling on Diversified Food Intake among Adult People Living with HIV on HAART, Northern Ethiopia

Background

HIV/AIDS and malnutrition are interrelated and exacerbate one another in a vicious cycle. As HIV infection progresses it causes catabolic state and increases susceptibility to other infections, leading to progressive aggravation of undernutrition. However, data are lacking in Ethiopia on determinants of undernutrition among people living with HIV on antiretroviral therapy. Therefore, this study aimed to assess determinants of undernutrition among adult HIV/AIDS patients in Northern Ethiopia.

Method

Facility-based unmatched case-control study was conducted among 324 randomly selected people living with HIV on antiretroviral therapy (ART). A structured and pretested interviewer questionnaire was used to collect data, while digital Seca weight and Seca measuring rod were used to measure weight and height, respectively. Logistic regression was used to identify independent factors of undernutrition, and p value <0.05 was declared for statistical significance. All statistical analyses were performed using SPSS 21™.

Result

This study revealed that people of younger age and those on ART (AOR = 0.29 (95% CI: 0.10, 0.84)) had low risk of being undernourished. However, average individual monthly income (AOR = 2.61 (95% CI: 1.48, 4.61)), not receiving nutritional counseling during visits (AOR = 2.5 (95% CI: 1.52–3.89)), and low diet diversity (AOR = 10.55 (95% CI: 4.17, 26.73)) had higher odds of undernutrition among people living with HIV/AIDS.

Conclusion

Age of patients, average monthly income, nutritional counseling during visits, and diet diversity were the independent factors of undernutrition. Counseling on well-timed and sufficient consumption of nutritious foods, economic strengthening, and livelihood activities is important. Future longitudinal study is necessary to elucidate the problem of undernutrition among people living with HIV/AIDS.

Apigenin alleviated acetaminophen-induced hepatotoxicity in low protein-fed rats: Targeting oxidative stress, STAT3, and apoptosis signals

Apigenin (API) is a natural flavonoid abundant in fruits and vegetables. The present study was undertaken to evaluate the effect of protein malnutrition (PMN) on acetaminophen (APAP)-induced hepatotoxicity, together with the protective effects of API, in male Wistar albino rats. In total, 64 male rats were divided into eight groups. Silymarin (SIL) (100 mg/kg, PO) as a reference standard and API (50 mg/kg, PO) were given to normal and APAP-induced hepatic injury in low protein-fed rats. The present results revealed that PMN significantly potentiated APAP-induced hepatotoxicity. Interestingly, the administration of SIL and API alleviated the induced damage, as revealed by reduced serum alanine aminotransferase and aspartate aminotransferase activities along with a significant improvement of the histopathological damage. API suppressed inflammatory response by reducing the interleukin-1β level and signal transducer and activator of transcription 3 expressions along with attenuating oxidative stress as shown by a significant reduction in liver contents of malondialdehyde and nitrite/nitrate as well as restoration of hepatic content of reduced glutathione and superoxide dismutase activity. API also counteracted apoptosis through downregulation of caspase-3 expression level. In conclusion, PMN greatly potentiated the hepatotoxic effects of APAP, and API produced a multimechanistic hepatoprotective activity that can be attributed to its antioxidant, anti-inflammatory, and antiapoptotic effects.

A Multidisciplinary Review of Nutrition Considerations in the Pediatric Oncology Population: A Perspective From Children's Oncology Group

Over the past few decades, great progress has been made in the survival rates of childhood cancer. As survival rates have improved, there has been an increased focus on supportive care. Nutrition is a supportive-care modality that has been associated with improved tolerance to chemotherapy, improved survival, increased quality of life, and decreased risk of infection in children undergoing anticancer therapy. Guidelines and assessment criteria have been proposed for the nutrition management of a child with cancer; however, there is no consistent use of criteria among institutions treating children with cancer. This review will present the current evidence and standards of practice incorporating aspects of nutrition, nursing, pharmacology, and psychosocial challenges to consider in the nutrition management of a child with cancer. Recommendations for clinical practice are presented.

Carbonated soft drinks alter hepatic cytochrome P450 isoform expression in Wistar rats

The aim of the current study was to examine the effects of chronic consumption of soft drinks (SDs) on hepatic oxidative stress and cytochrome P450 enzymes (CYPs) expression in the livers of Wistar rats. For 3 consecutive months, the rats had free access to three different soft drinks, Coca-Cola, Pepsi-Cola and 7-UP. The rats were subsequently compared with control group rats that had consumed water. Blood and hepatic tissue samples were assayed for the changes in antioxidants, liver function biomarkers and hepatic gene expression for different isoforms of hepatic CYP. The results indicated that SD consumption (SDC) decreased serum antioxidant levels and increased malondialdehyde secretion, and increased liver biomarkers (glutamate pyruvate transaminase and glutamate oxaloacetate). SD induced alterations in mRNA expression of hepatic antioxidants and cytochrome isoforms. The expression of peroxidase, catalase, CYP1A2, CYP3A2 and CYP2C11 in the liver were upregulated following SDC. By contrast, CYP2B1 was downregulated after 3 months of SDC in liver tissue samples. Thus, the present findings indicate that SDs induced oxidative stress in the liver of Wistar rats and for the first time, to the best of our knowledge, indicate that SDC disrupts hepatic CYP enzymes that may affect drug metabolism. Therefore, drug-dosing programs should be carefully designed to take these novel findings into consideration for the treatment of diseases.

Association between nutritional status and the immune response in HIV + patients under HAART: protocol for a systematic review

BACKGROUND

Over 850 million people worldwide and 200 million adults in Sub-Saharan Africa suffer from malnutrition. Countries most affected by HIV are also stricken by elevated rates of food insecurity and malnutrition. HIV infection and insufficient nutritional intake are part of a vicious cycle that contributes to immunodeficiency and negative health outcomes. However, the effect of the overlap between HIV infection and undernutrition on the immune response following antiretroviral initiation remains unclear. A possible explanation could be the lack of consensus concerning the definition and assessment of nutritional status. Our objectives are to investigate the existence of an association between undernutrition and immune response at antiretroviral treatment initiation and the following year in low- and middle-income countries where malnutrition is most prevalent.

METHODS/DESIGN

Our systematic review will identify studies originating from low- and middle-income countries (LMICs) published from 1996 onwards, through searches in MEDLINE (PubMed interface), EMBASE (OVID interface), Cochrane Central (OVID interface) and grey literature. No language restrictions will be applied. We will seek out studies of any design investigating the association between the nutritional status (for example, undernourished versus well nourished) and the immune response, either in terms of CD4 count or immune failure, in seropositive patients initiating antiretroviral therapy or in their first year of treatment. Two reviewers will independently screen articles, extract data and assess scientific quality using standardized forms and published quality assessment tools tailored for each study design. Where feasible, pooled measures of association will be obtained through meta-analyses. Results will be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. This protocol has been registered in the PROSPERO database (registration number: CRD42014005961).

CONCLUSION

Undernutrition and weight loss are prevalent amongst highly active antiretroviral therapy (HAART)-treated patients in LMICs and contribute to excess early mortality. A possible intermediate pathway could be poor immune reconstitution secondary to deficient nutritional status. In the face of limited access to second line treatments, raising HIV resistance and cut backs to HIV programs, it is crucial to identify the factors associated with suboptimal response and therapeutic failure in order to better customize the care strategies employed in LMICs.

Pharmacokinetics of lopinavir/ritonavir and efavirenz in food insecure HIV-infected pregnant and breastfeeding women in Tororo, Uganda

Pregnancy and food insecurity may impact antiretroviral (ART) pharmacokinetics (PK), adherence and response. We sought to quantify and characterize the PK of lopinavir/ritonavir (LPV/r) and efavirenz (EFV) by pregnancy and nutritional status among HIV-infected women in Tororo, Uganda. In 2011, 62/225 ante-partum/post-partum single dried blood spot samples DBS and 43 post-partum hair samples for LPV/r were derived from 116 women, 51/194 ante-/post-partum DBS and 53 post-partum hair samples for EFV from 105 women. Eighty percent of Ugandan participants were severely food insecure, 26% lost weight ante-partum, and median BMI post-partum was only 20.2 kg/m(2) . Rich PK-data of normally nourished (pregnant) women and healthy Ugandans established prior information. Overall, drug exposure was reduced (LPV -33%, EFV -15%, ritonavir -17%) compared to well-nourished controls (P < 0.001), attributable to decreased bioavailability. Pregnancy increased LPV/r clearance 68% (P < 0.001), whereas EFV clearance remained unchanged. Hair concentrations correlated with plasma-exposure (P < 0.001), explaining 29% PK-variability. In conclusion, pregnancy and food insecurity were associated with lower ART exposures in this cohort of predominantly underweight women, compared to well-nourished women. Much variability in plasma-exposure was quantified using hair concentrations. Addressing malnutrition as well as ART-PK in this setting should be a priority.

Influence of dietary macronutrients on induction of hepatic drug metabolizing enzymes by Coleus forskohlii extract in mice

From studies in mice, we have reported that Coleus forskohlii extract (CFE), a popular herbal weight-loss ingredient, markedly induced hepatic drug metabolizing enzymes, especially cytochrome P450 (CYP), and interacted with co-administered drugs. This study was designed to examine how the induction of drug metabolizing enzymes by CFE was influenced by different levels of macronutrients in the diet. Mice were fed a non-purified diet or semi-purified diet with and without CFE (0.3-0.5%) for 14-18 d, and changes in the ratio of liver weight to body weight, an indicator of hepatic CYP induction, and hepatic drug metabolizing enzymes were analyzed. The ratio of liver weight to body weight, content and activities of CYPs, and activity of glutathione S-transferase were higher in a semi-purified standard diet (AIN93G formula) group than in high sucrose (62.9%) and high fat (29.9%) diet groups. Different levels of protein (7%, 20%, and 33%) in the diets did not influence CFE-induced CYP induction or increase the ratio of liver weight to body weight. The effect of CFE on the ratio of liver weight to body weight was higher with a semi-purified diet than with a non-purified diet, and was similar between dietary administration and intragastric gavage when the CFE dose and the diet were the same. There was a positive correlation between CFE-induced CYP induction and the content of starch in the diets, suggesting that dietary starch potentiates CFE-induced CYP induction in mice. The mechanism of enhanced CYP induction remains unclear.

Effect of low-protein diet on anthracycline pharmacokinetics and cardiotoxicity

OBJECTIVES

Anthracyclines are broad spectrum anticancer drugs with dose-dependent cardiotoxicity. Protein malnutrition commonly occurs in cancer patients and is considered a risk factor for development of cardiotoxicity. This study was designed to assess the modulatory effect of protein malnutrition on the pharmacokinetics and drug disposition properties of a single dose of doxorubicin and epirubicin and how these possible changes will affect the degree of cardiotoxicity of these drugs.

METHODS

A single interperitoneal dose of 15 mg/kg of either doxorubicin or epirubicin was injected into rats fed with either normal protein diet or low-protein diet. The plasma concentration-time profiles of doxorubicin and epirubicin and their concentrations in different tissues were determined. Serum creatine kinase level was determined at different time intervals and histopathological examination of heart tissue was carried out.

KEY FINDINGS

Protein malnutrition significantly altered the pharmacokinetics of doxorubicin and epirubicin, with a significant decrease in their elimination, and prolonged the exposure of the heart to these drugs. Histopathological examination and serum creatine kinase measurements supported the role of protein malnutrition in enhancement of anthracycline cardiotoxicity.

CONCLUSIONS

If similar alteration in anthracyclines' pharmacokinetics occurs in malnourished cancer patients, protein malnutrition will be a risk factor for development of anthracycline cardiotoxicity and dose adjustment will be required in nutritionally deprived patients.

Effects of Ginkgo biloba extract on the pharmacokinetics and pharmacodynamics of tolbutamide in protein-restricted rats

Objectives

Effects of repeated administration of Ginkgo biloba extract on pharmacokinetics and pharmacodynamics of tolbutamide were examined in rats fed a low-protein diet.

Methods

Rats were given a low (7% casein) or control (20% casein) protein diet for 21 days and administered Ginkgo biloba extract (100 mg/kg per day) for the last 5 days. Tolbutamide was co-administered on the last day. Blood glucose and plasma tolbutamide concentrations were determined over the subsequent 12 h and the activity of hepatic cytochrome P450s were determined at 12 h after dosing.

Key findings

There were significant decreases in body weight, the ratio of liver to body weight, and plasma albumin concentrations in rats on the low-protein diet compared with controls. The hypoglycaemic effect of tolbutamide was significantly greater and the concentration of the drug in plasma was higher in the former group. The repeated administration of Ginkgo biloba extract had little influence on the hypoglycaemic effect of tolbutamide, but tended to decrease the drug concentration in plasma of control rats, while it reduced significantly the hypoglycaemic action and plasma concentration of tolbutamide in the protein-restricted rats.

Conclusions

The effects of Ginkgo biloba extract on the pharmacokinetics and pharmacodynamics of tolbutamide were significantly enhanced in rats on the low-protein diet.

Influence of CYP2C9 genetic polymorphism and undernourishment on plasma-free phenytoin concentrations in epileptic patients

The objective of this study was to study the effect of CYP2C9 genetic polymorphism and undernourishment on free phenytoin concentrations in epileptic patients. The study was done in 70 patients who were taking phenytoin therapy for the treatment of epileptic seizures. Genotyping of CYP2C9 (*2 and *3) was determined by the polymerase chain reaction-restriction fragment length polymorphism method. Bound and free plasma phenytoin was separated using equilibrium dialysis technique. Total and free phenytoin concentrations were measured by the reverse-phase high-performance liquid chromatography method. Patients were broadly classified into well-nourished and undernourished and further subclassified by CYP2C9 genotypes. In well-nourished groups (G1 to G3 group), free phenytoin concentrations were significantly higher in the heterozygous poor metabolizer of CYP2C9 genotype (G2) group (3.1 ± 0.62 μg/mL) and homozygous poor metabolizer of CYP2C9 genotype (G3) group (4.3 ± 1.76 μg/mL) when compared with patients with the wild-type CYP2C9 (G1) group (1.1 ± 0.72 μg/mL). Similarly, in undernourished patient groups (G4-G6 group), free phenytoin concentrations were significantly higher in the wild-type CYP2C9 (G4) group (2.5 ± 0.52 μg/mL), heterozygous poor metabolizer of CYP2C9 genotype (G5) group (4.3 ± 1.76 μg/mL), and homozygous poor metabolizer of CYP2C9 genotype (G6) group (8.2 ± 1.08 μg/mL) when compared with well-nourished patients with the wild-type CYP2C9 (G1) group (1.1 ± 0.72 μg/mL). The percentage increase in free phenytoin concentration by undernourishment, CYP2C9 allelic variants, and undernourishment cum CYP2C9 allelic variants were 127%, 290%, and 472%, respectively, compared with well-nourished patients with the wild-type CYP2C9 genotype (G1) group. The contribution of undernourishment and genetic factors (CYP2C9 allelic variant) for developing phenytoin toxicity was calculated to have an odds ratio of 37.3 (P < 0.0001). Undernourishment and variant CYP2C9 alleles elevate free phenytoin concentrations individually and in combination show additive effects.

Drug disposition in obesity and protein–energy malnutrition

Clinical response to medication can differ between patients. Among the known sources of variability is an individual's nutrition status. This review defines some pharmacokinetic terms, provides relevant body size metrics and describes the physiologic influences of protein–energy malnutrition and obesity on drug disposition. Weight-based drug dosing, which presumes a healthy BMI, can be problematic in the protein–energy malnourished or obese patient. The use of total body weight, lean body weight, or an adjusted body weight depends on the drug and how it is differently handled in malnutrition or obesity. Most of the recognized influences are seen in drug distribution and drug elimination as a result of altered body composition and function. Distribution characteristics of each drug are determined by several drug-related factors (e.g. tissue affinity) in combination with body-related factors (e.g. composition). Drug elimination occurs through metabolic and excretory pathways that can also vary with body composition. The current data are limited to select drugs that have been reported in small studies or case reports. In the meantime, a rational approach to evaluate the potential influences of malnutrition and obesity can be used clinically based on available information. Antimicrobials are discussed as a useful example of this approach. Further advancement in this field would require collaboration between experts in body composition and those in drug disposition. Until more data are available, routine monitoring by the clinician of the protein–energy malnourished or obese patient receiving weight-based drug regimens is necessary.

Effects of cysteine on metformin pharmacokinetics in rats with protein-calorie malnutrition: partial restoration of some parameters to control levels

Metformin is metabolized primarily via hepatic microsomal cytochrome P450 (CYP)2C11, CYP2D1 and CYP3A1/2 in rats. The expression and mRNA levels of hepatic CYP2C11 and CYP3A1/2 are decreased in rats with protein-calorie malnutrition (PCM), but these levels are fully or partially restored to control levels in PMC rats by oral cysteine supplementation (PCMC rats). Thus, it would be expected that the pharmacokinetic parameters of metformin in PCM rats would be returned to control levels in PCMC rats. Metformin was administered i.v. (100 mg kg−1) and orally (100 mg kg−1) to control, CC (control rats with oral cysteine supplementation), PCM and PCMC rats. The following pharmacokinetic parameters of metformin following i.v. administration were restored from levels in PCM rats to levels in control rats in PCMC rats: intrinsic clearance (0.0350, 0.0309, 0.0253 and 0.0316 mL min−1 mg−1 protein for control, CC, PCM, and PCMC rats, respectively), total area under the plasma concentration-time curve from time zero to time infinity (AUC; 4110, 4290, 5540 and 4430 μg min mL−1, respectively), and time-averaged non-renal clearance (8.12, 7.95, 5.94 and 8.17 mL min−1 kg−1, respectively). AUC values following oral administration were comparable between control and PCMC rats (1520, 1480, 2290 and 1680 μg min mL−1, respectively).

Potential interaction between warfarin and high dietary protein intake

A 55-year-old Caucasian man was receiving warfarin therapy after undergoing aortic valve replacement. His international normalized ratio (INR) was stabilized with warfarin 95 mg/week for 5 weeks. Commencement of a low-carbohydrate, high-protein diet resulted in a series of subtherapeutic INRs that led to a 16% increase in the dosage requirement to maintain therapeutic INRs. After the patient discontinued the diet, his INR increased, and several dosage reductions were required until his INR stabilized with his original dosage of 95 mg/week. Two additional case reports have described a possible interaction between warfarin and a high-protein diet. The potential for increased dietary protein intake to raise serum albumin levels and/or cytochrome P450 activity has been postulated as mechanisms for the resulting decrease in INRs. Given the available animal and human data that demonstrate alterations in drug metabolism in the presence of altered dietary protein intake, an increase in warfarin metabolism due to cytochrome P450 activation appears to be the most likely cause. In addition to the previously reported cases, this case indicates a potential interaction between warfarin and a high-protein diet. Because of the popularity of high-protein diets and because of the risks associated with inadequate or excessive warfarin anticoagulation, patients and health care providers should be aware of this interaction to ensure appropriate monitoring when warranted.

Effects of cysteine on the pharmacokinetic parameters of omeprazole in rats with protein-calorie malnutrition: partial restoration of some parameters to control levels by oral cysteine supplementation

BACKGROUND

It has been reported that omeprazole is mainly metabolized via the hepatic cytochrome (CYP) 1A1/2, 3A1/2, and 2D1, and the expressions and mRNA levels of CYP1A2, 2C11, and 3A1/2 decreased in protein-calorie malnutrition (PCM) rats compared with controls. Interestingly, the decreased CYP1A2, 2C11, and 3A1/2 in PCM rats returned fully or partially to control levels by oral cysteine supplementation (PCMC rats). Hence, it could be expected that some pharmacokinetic parameters of omeprazole might change in PCM rats and partially restore to control levels in PCMC rats. The purpose of this study is to investigate the pharmacokinetic changes of omeprazole in PCM rats and restoration of the parameters in PCMC rats to control levels.

METHODS

Omeprazole was administered intravenously (20 mg/kg) and orally (40 mg/kg) to control, PCM, and PCMC rats.

RESULTS

The following pharmacokinetic parameters were changed in PCM rats and partially returned to control levels in PCMC rats: the area under the plasma concentration-time curve (AUC; 387, 762, and 539 microg min/mL for control, PCM, and PCMC rats, respectively, after intravenous [IV] administration, and the corresponding values after oral administration: 115, 304, and 201 microg min/mL), total body clearance (51.7, 25.5, and 37.1 mL/min/kg, respectively), nonrenal clearance (51.5, 25.4, and 36.1 mL/min/kg, respectively), and in vitro intrinsic clearance (0.158, 0.118, and 0.138 mL/min/mg protein).

CONCLUSIONS

PCM was associated with significant changes in some omeprazole pharmacokinetics and the pharmacokinetic parameters restored to control levels by oral cysteine.