P450 oxidoreductase *28 (POR*28) and tacrolimus disposition in pediatric kidney transplant recipients--a pilot study.

BACKGROUND: Both age and CYP3A5 genotype are important determinants of tacrolimus disposition in pediatric kidney transplant recipients. In a recent study in adults, POR*28 was associated with increased dosing requirements early after transplant of CYP3A5-expressing kidney transplant recipients. The authors aimed to evaluate the additional contribution of POR*28 to early tacrolimus disposition in pediatric kidney transplant recipients. METHODS: Retrospective data of 43 pediatric kidney transplant recipients up to 14 days posttransplant were evaluated on tacrolimus dose and tacrolimus predose blood concentrations. Recipient POR*28 and CYP3A5 genotype were determined. RESULTS: CYP3A5 expressers carrying at least 1 POR*28 allele had on average 18.3% lower tacrolimus predose concentrations and 20.2% lower concentration/dose ratios compared with CYP3A5 expressers with POR*1/*1 genotype (P = 0.002 and P = 0.001, respectively). In CYP3A5 nonexpressers, tacrolimus disposition did not significantly differ between POR genotypes. CONCLUSIONS: In this small cohort of pediatric kidney transplant recipients, POR*28 genotype seems to explain part of the variability found in tacrolimus disposition, in addition to age and CYP3A5 genotype. This finding should be validated in a larger population, and it would be worthwhile to evaluate the clinical impact of this genotype.

Prevalence of renal dysfunction in tacrolimus-treated pediatric transplant recipients: a systematic review.

Renal dysfunction after non-renal transplantation in adult tacrolimus-treated transplant patients is well documented. Little is known about its prevalence in children. Age-related changes in both disposition and effect of tacrolimus as well as renal function may preclude extrapolation of adult data to children. To systematically review the literature on renal dysfunction in non-renal pediatric transplant recipients treated with tacrolimus. PubMed/Medline, Embase, and Google were searched from their inception until April 19, 2012, with the search terms "tacrolimus," "renal function," "transplantation," and "children." Eighteen of 385 retrieved papers were considered relevant. Twelve dealt with liver, four with heart transplant, one with heart and lung transplant, and one with intestinal recipients. Reported prevalences of mild and severe chronic kidney disease ranged from 0% to 39% and 0% to 71.4%, respectively, for liver, and from 22.7% to 40% and 6.8% to 46%, respectively, for heart and/or lung transplant recipients. Ranges remained wide after adjusting for follow-up time and disease severity. Possible explanations are inclusion bias and definitions used for renal dysfunction. A considerable proportion of pediatric non-renal transplant patients who receive tacrolimus-based immunosuppression, appear to suffer from chronic kidney disease. This conclusion warrants further research into the real risk, its risk factors, and individualization of immunosuppressant therapy.

CYP2D6 polymorphisms and codeine analgesia in postpartum pain management: a pilot study.

BACKGROUND: Codeine, a common opiate prescribed for pain postcesarean section (c-section), is biotransformed by the highly polymorphic Cytochrome P450 enzyme 2D6 (CYP2D6). Ultrarapid metabolizers (UMs), individuals with multiple active copies of CYP2D6, can biotranform up to 50% more codeine into morphine than normal individuals can. In contrast, poor metabolizers (PMs), individuals who have no active CYP2D6 genes, convert almost no codeine into morphine and as a result may take multiple doses of codeine without attaining analgesia. OBJECTIVE: The aim was to study the relationship between CYP2D6 genotype and codeine analgesia among women recovering from c-section. METHODS: Forty-five mothers prescribed codeine provided a blood sample for CYP2D6 genotyping and recorded their pain level 4 times a day for 3 days immediately after a c-section. Codeine was used on an as-needed basis; doses and times were recorded. The relationship between CYP2D6 genotype, pain scores, need for codeine, and adverse events was studied. Theoretical morphine dose, based on CYP2D6 genotype, was estimated. RESULTS: Women at the genotypic extremes reported codeine effects consistent with their genotype: the 2 PMs of codeine reported no analgesia as a result of taking codeine, whereas 2 of the 3 UMs reported immediate pain relief from codeine but stopped taking it due to dizziness and constipation. Much larger numbers are needed to study similar correlations among extensive and intermediate metabolizers. CONCLUSIONS: In this pilot study, the extreme CYP2D6 genotypes (PMs and UMs) seemed to predict pain response and adverse events. Larger sample sizes are needed to correlate the range of genotypes with pain response.

Probability of rash related to gabapentin therapy in a child.

OBJECTIVE: To describe a child who developed a skin reaction during gabapentin therapy and discuss how we evaluated the probability of an adverse drug reaction. CASE SUMMARY: An 8-year-old boy with a neurodegenerative disease of unknown origin and an epilepsy disorder developed an urticarial rash and irritability 10 and 4 days, respectively, after the start of gabapentin 20 mg/kg 3 times a day for epilepsy control. Otherwise, the child was well; no changes in other medication or diet had recently been made. After gabapentin discontinuation and administration of one dose of methylprednisolone 10 mg/kg intravenously and diphenhydramine 1 mg/kg every 4 hours via gastric tube, the rash disappeared over 3 weeks. DISCUSSION: In contrast to other antiepileptic drugs, skin reactions to gabapentin are considered uncommon. In adults, reported prevalence of rash possibly related to gabapentin range from 1% to 10%. A postmarketing surveillance study reported gabapentin treatment failure as a consequence of rash in 0.4% of 3000 patients. The product monograph does not mention rash in children. In our patient, assessment using an objective causality scale revealed that the rash was probably caused by gabapentin. CONCLUSIONS: This case, and limited literature data, suggest that gabapentin may cause rash that is severe enough to necessitate discontinuation in a small percentage of children. Further research is needed to determine the actual incidence and severity of gabapentin-related rash in this population.

CYP3A4*22 and CYP3A combined genotypes both correlate with tacrolimus disposition in pediatric heart transplant recipients.

BACKGROUND: Tacrolimus metabolism depends on CYP3A4 and CYP3A5. We aimed to determine the relationship between the CYP3A4*22 polymorphism and combined CYP3A genotypes with tacrolimus disposition in pediatric heart transplant recipients. METHODS: Sixty pediatric heart transplant recipients were included. Tacrolimus doses and trough concentrations were collected in the first 14 days post-transplantation. CYP3A phenotypes were defined as extensive (CYP3A5*1 + CYP3A4*1/*1 carriers), intermediate (CYP3A5*3/*3 + CYP3A4*1/*1 carriers) or poor (CYP3A5*3/*3 + CYP3A4*22 carriers) metabolizers. RESULTS: CYP3A4*22 carriers needed 30% less tacrolimus (p = 0.016) to reach similar target concentrations compared with CYP3A4*1/*1 (n = 56) carriers. Poor CYP3A metabolizers required 17% (p = 0.023) less tacrolimus than intermediate and 48% less (p < 0.0001) than extensive metabolizers. Poor metabolizers showed 18% higher dose-adjusted concentrations than intermediate (p = 0.35) and 193% higher than extensive metabolizers (p < 0.0001). CONCLUSION: Analysis of CYP3A4*22, either alone or in combination with CYP3A5*3, may help towards individualization of tacrolimus therapy in pediatric heart transplant patients.

Tacrolimus-induced nephrotoxicity and genetic variability: a review.

BACKGROUND: Calcineurin inhibition (CNI) is the mainstay of immunosuppressant therapy for most solid organ transplant patients. High tacrolimus levels are related with acute nephrotoxicity, but the relationship with chronic toxicity is less clear. Variation in disposition of tacrolimus is associated with genetic variation in CYP3A5. Hence, could genetic variation in CYP3A5 or other genes involved in tacrolimus disposition and effect be associated with a risk for tacrolimus-induced nephrotoxicity? To perform a review of the literature and to identify if genetic variation in CYP3A5 or other genes involved in tacrolimus disposition or effect may be associated with tacrolimus-induced nephrotoxicity and/or renal dysfunction in solid organ transplant recipients. MATERIAL/METHODS: Pubmed/Medline, Embase and Google were searched from their inception till November 8th 2010 with the search terms 'tacrolimus', 'genetics', and 'nephrotoxicity' or 'renal dysfunction'. References of relevant articles were screened as well. RESULTS: We identified 13 relevant papers. In kidney recipients, associations between donor ABCB1, recipient CCR5 genotype and tacrolimus-induced nephrotoxicity were found. CYP3A5 genotype studies in kidney recipients yielded contradictory results. In liver recipients, a possible association between recipient ACE, CYP3A5, ABCB1 and CYP2C8 genetic polymorphisms and tacrolimus-induced nephrotoxicity was suggested. In heart recipients, TGF-ß genetic polymorphisms were associated with tacrolimus-induced nephrotoxicity. The quality of the studies varied considerably. CONCLUSIONS: Limited evidence suggests that variation in genes involved in pharmacokinetics (ABCB1 and CYP3A5) and pharmacodynamics (TGF-ß, CYP2C8, ACE, CCR5) of tacrolimus may impact a transplant recipients' risk to develop tacrolimus-induced nephrotoxicity across different transplant organ groups.

The effect of distant reiki on pain in women after elective Caesarean section: a double-blinded randomised controlled trial.

INTRODUCTION: Approximately 25% of all babies in North America are delivered via Caesarean section (C-section). Though a common surgical procedure, C-section recovery can be painful. Opioids, specifically codeine, are commonly used to ease pain; however, its active metabolite, morphine, passes into breast milk, and may produce unwanted side effects in neonates; therefore, alternatives to opioids are being sought. Reiki is an ancient Japanese form of healing where practitioners transfer healing energy through light touch and positive healing intention. Although 1.2 million Americans use reiki to reduce pain or depression, there is a lack of strong evidence supporting its effectiveness. A recent systematic review showed existing studies to be of poor methodological quality, with the common limitation of lack of blinding. To overcome this issue, the authors used distant reiki to assess its effectiveness in reducing pain following an elective C-section. METHODS: In this randomised, double-blinded study, women who underwent an elective C-section were allocated to either usual care (control, n=40) or three distant reiki sessions in addition to usual care (n=40). Pain was assessed using a visual analogue scale (VAS). The primary endpoint was the Area Under the VAS-Time Curve (AUC) for days 1-3. Secondary measures included: the proportion of women who required opioid medications and dose consumed, rate of healing and vital signs. RESULTS: AUC for pain was not significantly different in the distant reiki and control groups (mean ± SD; 212.1 ± 104.7 vs 223.1 ± 117.8; p=0.96). There were no significant differences in opioid consumption or rate of healing; however, the distant reiki group had a significantly lower heart rate (74.3 ± 8.1 bpm vs 79.8 ± 7.9 bpm, p=0.003) and blood pressure (106.4 ± 9.7 mmHg vs 111.9 ± 11.0 mmHg, p=0.02) post surgery. CONCLUSION: Distant reiki had no significant effect on pain following an elective C-section. Clinical Trial Registration Number ISRCTN79265996.

A systematic review of the therapeutic effects of Reiki.

INTRODUCTION: Reiki is an ancient form of Japanese healing. While this healing method is widely used for a variety of psychologic and physical symptoms, evidence of its effectiveness is scarce and conflicting. The purpose of this systematic review was to try to evaluate whether Reiki produces a significant treatment effect. METHODS: Studies were identified using an electronic search of Medline, EMBASE, Cochrane Library, and Google Scholar. Quality of reporting was evaluated using a modified CONSORT Criteria for Herbal Interventions, while methodological quality was assessed using the Jadad Quality score. DATA EXTRACTION: Two (2) researchers selected articles based on the following features: placebo or other adequate control, clinical investigation on humans, intervention using a Reiki practitioner, and published in English. They independently extracted data on study design, inclusion criteria, type of control, sample size, result, and nature of outcome measures. RESULTS: The modified CONSORT Criteria indicated that all 12 trials meeting the inclusion criteria were lacking in at least one of the three key areas of randomization, blinding, and accountability of all patients, indicating a low quality of reporting. Nine (9) of the 12 trials detected a significant therapeutic effect of the Reiki intervention; however, using the Jadad Quality score, 11 of the 12 studies ranked "poor." CONCLUSIONS: The serious methodological and reporting limitations of limited existing Reiki studies preclude a definitive conclusion on its effectiveness. High-quality randomized controlled trials are needed to address the effectiveness of Reiki over placebo.