Adverse reactions to trimethoprim-sulfamethoxazole among children with human immunodeficiency virus infection

Renal Impairment Associated With Trimethoprim-Sulfamethoxazole Use in the Pediatric Population

OBJECTIVE

Limited studies describe acute kidney injury (AKI) in children receiving trimethoprimsulfamethoxazole (SXT). The primary objective of this study was to describe AKI with SXT use in pediatric patients. Secondary objectives included describing the incidence of hyperkalemia and blood dyscrasias with SXT use.

METHODS

In this retrospective, single-center observational study, inpatient electronic medical records were reviewed for patients younger than 18 years of age who received at least 5 days of SXT for treatment of a bacterial infection. Patients were excluded if serum creatinine data prior to and after initiation of SXT were unavailable, they had AKI or were on hemodialysis prior to SXT initiation, or they were admitted to an oncology unit.

RESULTS

Of 98 patients who met inclusion criteria, 24 (24.5%) experienced stage I AKI and 16 (16.3%) experienced stage II or III AKI. The mean treatment duration with SXT at time of AKI development was 5.9 days. Coadministration of SXT with other nephrotoxic medications increased the risk of development of AKI (OR, 1.7; 95% CI, 1.2-2.4). Hyperkalemia was noted in 29 patients (29.6%), anemia in 39 patients (39.8%), thrombocytopenia in 30 (30.6%), and neutropenia in 39 (39.8%).

CONCLUSIONS

Changes in renal function suggestive of AKI occur frequently in pediatric patients receiving at least 5 days of treatment with SXT, particularly when using serum creatinine as a marker of AKI. In contrast, when using urine output rather than serum creatinine, the incidence is much lower and may be more reflective of a true change in renal function. Coadministration of nephrotoxic agents increases the risk of development of AKI. Anemia and hyperkalemia are common in patients receiving SXT and not associated with development of AKI. Further prospective study is warranted to validate these results.

Detection of Pneumocystis jirovecii in Hospitalized Children Less Than 3 Years of Age

Few data are available in the literature regarding Pneumocystis jirovecii infection in children under 3 years old. This retrospective cohort study aimed to describe medically relevant information among them. All children under 3 years old treated in the same medical units from April 2014 to August 2020 and in whom a P. jirovecii evaluation was undertaken were enrolled in the study. A positive case was defined as a child presenting at least one positive PCR for P. jirovecii in a respiratory sample. Medically relevant information such as demographical characteristics, clinical presentation, microbiological co-infections, and treatments were collected. The objectives were to describe the characteristics of these children with P. jirovecii colonization/infection to determine the key underlying diseases and risk factors, and to identify viral respiratory pathogens associated. The PCR was positive for P. jirovecii in 32 children. Cardiopulmonary pathologies (21.9%) were the most common underlying disease in them, followed by severe combined immunodeficiency (SCID) (18.8%), hyaline membrane disease (15.6%), asthma (9.4%) and acute leukaemia (6.3%). All SCID children were diagnosed with pneumocystis pneumonia. Co-infection with Pj/Rhinovirus (34.4%) was not significant. Overall mortality was 18.8%. Paediatric pneumocystis is not restricted to patients with HIV or SCID and should be considered in pneumonia in children under 3 years old.

Prophylaxis With Trimethoprim/Sulfamethoxazole Is Not Necessary in Children With Solid Tumors Treated With Low-medium Intensity Chemotherapy

Prophylaxis of Pneumocystis jiroveci pneumonia (PJP) with trimethoprim/sulfamethoxazole is a standard of care for children with hematologic malignancies, while its use in solid tumor patients is still debated. A retrospective study focusing on the use of PJP prophylaxis in patients with solid tumors was performed among 16 AIEOP centers: 1046/2863 patients did not receive prophylaxis and no cases of PJP were reported.

Effect of co-trimoxazole prophylaxis on morbidity and mortality of HIV-exposed, HIV-uninfected infants in South Africa: a randomised controlled, non-inferiority trial

BACKGROUND

WHO guidelines recommend co-trimoxazole prophylaxis for HIV-exposed, HIV-uninfected infants. These guidelines date back to an era in which HIV testing of infants was impossible and mothers had poor access to antiretroviral treatment. To determine whether this guideline requires revision in the current era of effective prevention of mother-to-child transmission and early infant diagnosis programmes, we aimed to investigate whether receiving no co-trimoxazole prophylaxis is inferior to receiving co-trimoxazole prophylaxis in the resulting incidence of grade 3 or 4 common childhood illnesses or mortality in breastfed HIV-exposed, HIV-uninfected infants.

METHODS

We investigated our aim in a randomised controlled, non-inferiority trial. We enrolled the HIV-negative infants of mothers living with HIV who were actively involved in transmission prevention programmes in two clinics in Durban, South Africa. Infants were included in the study if they were breastfeeding at the screening and enrolment visits, and their mother was planning to breastfeed for at least 6 months; were a singleton birth and had a birthweight of 2 kg or more; had no clinically observed genetic disorders; and had no serious illnesses and had not received antibiotics or traditional medications (such as herbal remedies). Infants were randomly assigned (1:1) to receive co-trimoxazole or no co-trimoxazole. In the co-trimoxazole group, infants received the drug until all exposure to HIV had ceased (ie, 6 weeks after last exposure to breastmilk) and the infant was confirmed to be uninfected with HIV. The drug was administered by mothers in once-daily regimens of 20 mg trimethoprim and 100 mg sulfamethoxazole orally (age <6 months or bodyweight <5 kg), or 40 mg trimethoprim and 200 mg sulfamethoxazole orally (age >6 months or bodyweight >5 kg). Clinical and laboratory staff always remained masked to group assignment, but mothers and study counsellors were not. Infants and their mothers attended study visits at ages 6 weeks (for enrolment and randomisation), 10 weeks, 14 weeks, and then monthly from 4 to 12 months. Our primary outcome was the incidence of grade 3 or 4 common childhood illnesses (pneumonia or diarrhoea) or mortality in breastfed HIV-exposed, HIV-uninfected infants by age 12 months. A non-inferiority bound of 5% was used. The study is registered with the Pan African Clinical Trials Registry, number PACTR201311000621110, and the South African National Clinical Trials Registry, number DOH-27-0614-4728.

FINDINGS

We screened 1570 mother-child pairs for study enrolment, from whom (78%) eligible infants were enrolled into the study between Oct 16, 2013, and May 23, 2018. Of the infants enrolled, 611 (50%) were randomly assigned to the co-trimoxazole group and 609 (50%) were randomly assigned to the no co-trimoxazole group. One (<1%) infant in the no co-trimoxazole group was excluded from the analysis of the final outcomes for having received traditional medicine (which only became apparent after randomisation); therefore, 611 (50%) infants in the co-trimoxazole group and 608 (50%) infants in the no co-trimoxazole group were included in the final intention-to-treat analysis. 136 (22%) infants in the co-trimoxazole group and 139 (23%) infants in the no co-trimoxazole group did not complete the 12-month study visit, predominantly because of loss to follow-up (93 [15%] infants in the co-trimoxazole group; 90 [15%] infants in the no co-trimoxazole group). The cumulative probability of the composite primary outcome was 0·114 (95% CI 0·076 to 0·147; 49 events) in the co-trimoxazole group versus 0·0795 (0·044 to 0·115; 39 events) in the no co-trimoxazole group. The risk difference (no co-trimoxazole group minus co-trimoxazole group) was -0·0319 (-0·075 to 0·011), meaning that the risk was around 3 percentage points lower in the no co-trimoxazole group on the additive scale.

INTERPRETATION

We can conclude that no co-trimoxazole is not inferior to daily co-trimoxazole among breastfed HIV-exposed, HIV-uninfected infants whose mothers are accessing a prevention of mother-to-child transmission programme in an area unaffected by malaria. We therefore believe that WHO should revise the co-trimoxazole guidelines for HIV-exposed, HIV-uninfected infants in areas unaffected by malaria.

FUNDING

HIV Prevention Research Unit of the South African Medical Research Council and the Family Larsson-Rosenquist Foundation.

Pneumocystis Pneumonia: Still a serious disease in children

Pneumocystis carinii pneumonia is a common opportunistic respiratory infection among children with human immunodeficiency virus and a weakened immune system. The primary infection in immunocompetent patients may be asymptomatic, whereas fever, shortness of breath, night sweats, nonproductive (dry) cough, pneumonia, progressive respiratory distress and apnea are cardinal symptoms of full-blown pneumocystis pneumonia. The diagnosis can be confirmed by histochemical staining of biological specimens or, recently, by polymerase chain reaction. International recommendations indicate that the drug of choice is the intravenously administered trimethoprim-sulfamethoxazole combination. Early diagnosis and appropriate treatment reduce the mortality of the disease. This article briefly highlights the epidemiology of Pneumocystis pneumonia, its diagnosis and therapeutic options in the pediatric population.

Miscibility of poly(acrylic acid)/poly(methyl vinyl ketone) blend and in vitro application as drug carrier system

A series of poly(acrylic acid)/poly(methyl vinyl ketone) (PAA/PMVK) blends with different compositions were prepared by the solvent casting method. The miscibility of this pair of polymers was investigated by differential scanning calorimetry(DSC), Fourier transform infra-red (FTIR) and X-Ray diffraction (XRD) techniques. An in-vitro cytotoxicity test of the drug-carrier system via MTT (3-(4,5-demethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay revealed no significant cytotoxic effects at concentrations up to 100 µg· ml⁻¹. The STX/PAA-50 drug carrier systems were also prepared by solvent casting of solutions containing the sulfamethoxazole (STX) used as drug model and PAA/PMVK blend in N.N-dimethylformamide then crosslinked with acidified ethylene glycol. The release dynamic of STX from the prepared hydrogels was investigated in which the diffusion through the polymer matrix, the enhancement of the water solubility of STX, the influence of the initial drug concentration, the pH of the medium, and the effect of the degree of swelling of the polymer matrix on the release dynamic was evaluated. According to the total gastrointestinal transit time estimated by Belzer, the estimate distribution of STX released in the different organs indicated that the performance is obtained with the drug – carrier-system containing equal ratios of polymer and 10 wt% of STX (STX-10/PAA-50).

Silver-filled MWCNT nanocomposite as a sensing element for voltammetric determination of sulfamethoxazole

Here, we introduce a new electrode based on Silver-filled multi-walled carbon nanotube (Ag-MWCNT) and methyltrioctyl ammonium chloride (MTOAC) for highly sensitive voltammetric measurement of Sulfamethoxazole (SMX). The electrode showed an electrocatalytic activity as it led to the diminution of the overpotential and an increase in peak current for SMX oxidation in a phosphate buffer solution (pH 6.0). Analysis of surface topography and electrochemical properties of the modified electrode was examined by TEM, EDX and EIS, respectively. Electrochemical performance of the modified electrode was investigated with cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques for determination of SMX in aqueous solution. In addition, the oxidation process was found to be dependent on the pH of the buffer solution. Under optimal conditions, a linear relationship between the oxidation current and SMX concentration was found in a range 0.05-70 μM (R² = 0.997) with a detection limit of 0.01 μM after 2 min of accumulating time. The electrode was successfully used to quantify SMX in pharmaceutical formulations and human urine by DPV.

Randomised controlled trial testing the effect of cotrimoxazole prophylaxis on morbidity and mortality outcomes in breastfed HIV-exposed uninfected infants: study protocol

INTRODUCTION

No randomised controlled trial (RCT) has examined the efficacy of cotrimoxazole (CTX) prophylaxis in HIV-exposed uninfected (HEU) infants during the breastfeeding period, in this new era of effective prevention of mother-to-child transmission (PMTCT) prophylaxis. The efficacy of CTX prophylaxis has presently been demonstrated only in HIV-infected children. The absence of proven benefits in HEU breastfed infants associated with infectious diseases justifies an RCT as proposed. Herewith lies the rationale for conducting the proposed study.

METHODS

A partially blinded RCT is proposed to evaluate the efficacy of CTX prophylaxis administered from 6 weeks of age to HEU infants receiving a PMTCT regimen. A non-inferiority design will be used, randomising 1298 infants to receive CTX or not to receive CTX. Participants will be reviewed at the following time points: 6 weeks (enrolment and randomisation), 10 weeks, 14 weeks, 4 months and monthly thereafter until 12 months of age. They will be evaluated for anthropometric growth, interval illness, CTX adherence, signs and symptoms of study drug toxicity, concomitant medication use, breastfeeding status and HIV infection status. The study will compare the incidence of grade 3 and grade 4 common childhood illnesses (focusing on pneumonia and diarrhoea) and all-cause mortality until 12 months of age. In a subset of participants, we will compare grade 3 and grade 4 haemoglobin and alanine aminotransferase results as well as investigate gut integrity.

ETHICS AND DISSEMINATION

The study has ethical approval from the University of KwaZulu-Natal Biomedical Research Ethics Committee (BFC212/13).

TRIAL REGISTRATION NUMBERS

PACTR201311000621110 and DOH-27-0614-4728; Pre-results.

The expanding role of co-trimoxazole in developing countries

Co-trimoxazole is an inexpensive, broad-spectrum antimicrobial drug that is widely used in developing countries. Before antiretroviral therapy (ART) scale-up, co-trimoxazole prophylaxis reduced morbidity and mortality in adults and children with HIV by preventing bacterial infections, diarrhoea, malaria, and Pneumocystis jirovecii pneumonia, despite high levels of microbial resistance. Co-trimoxazole prophylaxis reduces early mortality by 58% (95% CI 39-71) in adults starting ART. Co-trimoxazole provides ongoing protection against malaria and non-malaria infections after immune reconstitution in ART-treated individuals in sub-Saharan Africa, leading to a change in WHO guidelines, which now recommend long-term co-trimoxazole prophylaxis for adults and children in settings with a high prevalence of malaria or severe bacterial infections. Co-trimoxazole prophylaxis is recommended for HIV-exposed infants from age 4-6 weeks; however, the risks and benefits of co-trimoxazole during infancy are unclear. Co-trimoxazole prophylaxis reduces anaemia and improves growth in children with HIV, possibly by reducing inflammation, either through direct immunomodulatory activity or through effects on the intestinal microbiota leading to reduced microbial translocation. Ongoing trials are now assessing the ability of adjunctive co-trimoxazole to reduce mortality in children after severe anaemia or severe acute malnutrition. In this Review, we discuss the mechanisms of action, benefits and risks, and clinical trials of co-trimoxazole in developing countries.

Impact of HIV exposure on health outcomes in HIV-negative infants born to HIV-positive mothers in Sub-Saharan Africa

BACKGROUND

Up to 30% of infants may be HIV-exposed noninfected (ENI) in countries with high HIV prevalence, but the impact of maternal HIV on the child's health remains unclear.

METHODS

One hundred fifty-eight HIV ENI and 160 unexposed (UE) Mozambican infants were evaluated at 1, 3, 9, and 12 months postdelivery. At each visit, a questionnaire was administered, and HIV DNA polymerase chain reaction and hematologic and CD4/CD8 determinations were measured. Linear mixed models were used to evaluate differences in hematologic parameters and T-cell counts between the study groups. All outpatient visits and admissions were registered. ENI infants received cotrimoxazol prophylaxis (CTXP). Negative binomial regression models were estimated to compare incidence rates of outpatient visits and admissions.

RESULTS

Hematocrit was lower in ENI than in UE infants at 1, 3, and 9 months of age (P = 0.024, 0.025, and 0.012, respectively). Percentage of CD4 T cells was 3% lower (95% confidence interval: 0.86 to 5.15; P = 0.006) and percentage of CD8 T cells 1.15 times higher (95% confidence interval: 1.06 to 1.25; P = 0.001) in ENI vs. UE infants. ENI infants had a lower weight-for-age Z score (P = 0.049) but reduced incidence of outpatient visits, overall (P = 0.042), diarrhea (P = 0.001), and respiratory conditions (P = 0.042).

CONCLUSIONS

ENI children were more frequently anemic, had poorer nutritional status, and alterations in some immunologic profiles compared with UE children. CTXP may explain their reduced mild morbidity. These findings may reinforce continuation of CTXP and the need to understand the consequences of maternal HIV exposure in this vulnerable group of children.

Stevens-Johnson syndrome and HIV in children in Swaziland

BACKGROUND

Stevens-Johnson syndrome (SJS) can be a severe and life-threatening reaction with many potential causes, including multiple medications used in HIV care and treatment. Specific risk factors, especially in children, are not currently well-understood.

METHODS

We describe a series of cases of SJS that occurred from 2006 to 2010 in an HIV-focused clinic in Mbabane, Swaziland. The electronic medical and pharmacy records of all pediatric patients <20 years old were reviewed to identify cases of SJS. Patient demographic, immunosuppression and outcome data were also collected.

RESULTS

A total of 19 cases of SJS were documented. Eighty-four percent of cases were attributed to nevirapine (NVP) exposure whereas the remaining cases were caused by cotrimoxazole (11%) and efavirenz (5%). Median symptom onset was 22 days after initiation of the offending medication (interquartile range = 14-25 days). At time of SJS, 84% had advanced or severe immunosuppression. Forty-two percent of patients required hospitalization, and no SJS-associated deaths were known to occur. Use of efavirenz was attempted in 8 NVP-associated cases after SJS resolution and was successful in all except 1.

CONCLUSIONS

SJS occurrence was rare in this population, with the majority of cases being associated with NVP. All occurred within 32 days of medication initiation, providing a target window for intensified monitoring and anticipatory guidance. SJS can occur in children at any age, with any level of immunosuppression, and can occur during the lead-in dosing period of NVP.

Trends in adverse reactions to trimethoprim-sulfamethoxazole

OBJECTIVE

To examine temporal trends of adverse drug reactions (ADRs) associated with trimethoprim-sulfamethoxazole (TMP-SMX) use in children.

METHODS

We performed a retrospective observational study to characterize TMP-SMX ADRs in children between 2000 and 2009. We completed a chart review at our institution by identifying children diagnosed with TMP-SMX ADRs. To compare local trends to comparable institutions, we estimated the frequency of hospitalizations for TMP-SMX ADRs at 25 tertiary pediatric hospitals utilizing the Pediatric Health Information System database. To determine whether changes in outpatient prescribing rates occurred, we used the National Ambulatory Medical Care Survey/National Hospital Ambulatory Medical Care Survey.

RESULTS

At our institution, 109 children were diagnosed with a TMP-SMX ADR (5 cases from 2000 to 2004 as compared with 104 cases from 2005 to 2009). Fifty-eight percent had been treated for a skin and soft tissue infection (SSTI). A similar trend was observed nationally, where the incidence of TMP-SMX ADRs more than doubled from 2004 to 2009 at comparable pediatric hospitals (P < .001). Although national outpatient data revealed no change in overall TMP-SMX prescribing, the percentage of children prescribed TMP-SMX for SSTI sharply increased during the study period (0%-2% [2000-2004]; 9%-17% [2005-2009]).

CONCLUSIONS

The majority of TMP-SMX ADRs at our institution occurred in conjunction with SSTI treatment. TMP-SMX ADRs have occurred more frequently coincident with increased prescribing for SSTI. Increased usage alone may explain the increasing trend of TMP-SMX ADRs in children; however drug-disease interaction may play a role and requires further investigation.

Extended prophylaxis with nevirapine and cotrimoxazole among HIV-exposed uninfected infants is well tolerated

OBJECTIVE

Nevirapine and cotrimoxazole are associated with hematologic toxicities and skin-rash. Safety of their concurrent use for prophylaxis over extended periods among HIV-exposed uninfected infants has not been previously assessed.

DESIGN

Secondary data analysis of the 'HIV Prevention Trials Network-046 protocol' (version 2.0), a phase-III, randomized, placebo-controlled trial that assessed efficacy and safety of nevirapine prophylaxis against breast milk transmission of HIV-1.

METHODS

Trial infants received 6-month study nevirapine/placebo, and standard-of-care peripartum single-dose nevirapine+/- zidovudine 'tail', and cotrimoxazole prophylaxis from 6 weeks through breastfeeding cessation. Adverse events were monitored using United States Division of AIDS Toxicity Tables (2004). Risk of neutropenia, anemia and skin-rash in the cotrimoxazole + nevirapine and the cotrimoxazole + placebo groups were compared using negative-binomial regression.

RESULTS

Incidence of neutropenia and/or anemia, and skin-rash was highest during the first 6 weeks of life and declined, thereafter, regardless of study group. Time to first adverse event after 6 weeks was similar in cotrimoxazole + nevirapine and cotrimoxazole + placebo groups: hazard ratio (95% confidence interval) was 1.26 (0.96-1.66) for neutropenia and/or anemia (all grades), 1.27 (0.80-2.03) for neutropenia and/or anemia (grade ≥3) and 1.16 (0.46-2.90) for skin-rash (grade ≥2). There were no statistically significant differences in immediate (6 weeks-6 months) and long-term (6-12 months) adverse event risk among infants on cotrimoxazole + nevirapine versus cotrimoxazole + placebo.

CONCLUSION

Extended nevirapine and cotrimoxazole prophylaxis through 6 months of age among HIV-exposed uninfected infants did not appear to increase the immediate or long-term risk of neutropenia, anemia or skin-rash. Concurrent use beyond 6 months, however, needs to be evaluated.

Pneumocystis pneumonia in children

Pneumocystis pneumonia (PCP) is a life-threatening infection in immunocompromised children with quantitative and qualitative defects in T lymphocytes. At risk are children with lymphoid malignancies, HIV infection, corticosteroid therapy, transplantation and primary immunodeficiency states. Diagnosis is established through direct examination or polymerase chain reaction (PCR) from respiratory secretions. Trimethoprim-sulphamethoxazole is used for initial therapy in most patients, while pentamidine, atovaquone, clindamycin plus primaquine, and dapsone plus trimethoprim are alternatives. Prophylaxis of high-risk patients reduces but does not eliminate the risk of PCP. Improved understanding of the pathogenesis of PCP is important for future advances against this life-threatening infection.

TNF, LTA, HSPA1L and HLA-DR gene polymorphisms in HIV-positive patients with hypersensitivity to cotrimoxazole

AIMS

Sulfamethoxazole in combination with trimethoprim (cotrimoxazole) is used for prophylaxis and treatment of several opportunistic infections in HIV-infected patients. It is associated with a high incidence of hypersensitivity reactions, which is thought to have an immune basis. Genetic polymorphisms in MHC are known to predispose to hypersensitivity reactions to a structurally diverse group of drugs in HIV-positive patients. The aim of the study was to determine whether functional polymorphisms in TNF, LTA, HSPA1L and HLA-DRB1 genes influence the risk of cotrimoxazole hypersensitivity in HIV-infected patients.

METHODS

We genotyped 136 HIV-positive patients with (n = 53) and without (n = 83) cotrimoxazole hypersensitivity using a combination of PCR-based techniques, including PCR-restriction fragment length polymorphisms, PCR-sequence specific oligonucleotides and real-time PCR. Genotypes and the haplotype frequencies were analyzed using the chi(2) test in the Haploview and CLUMP programs.

RESULTS

No statistically significant difference in SNP or haplotype frequencies were found in HIV-infected sulfamethoxazole hypersensitive patients compared with controls.

CONCLUSION

Our data show that MHC polymorphisms are not major predisposing factors for cotrimoxazole hypersensitivity, although we cannot exclude a minor contribution. An environmental factor (i.e., HIV infection) seems to predominate over any of the genetic factors so far investigated in increasing the risk of cotrimoxazole hypersensitivity.

Increased adverse drug reactions to antimicrobials and anticonvulsants in patients with HIV infection

OBJECTIVE

To review the incidence, signs, symptoms, and mechanisms of adverse drug reactions (ADRs) to sulfonamides, anticonvulsants, and antimycobacterial medications among people with HIV.

DATA SOURCES

Searches of MEDLINE/PubMed (1980-November 2005) and National Library of Medicine Meeting Abstracts (1989-November 2005), as well as hand searches of journals and abstracts, were conducted to identify primary literature. Reference lists were reviewed to identify additional relevant reports.

STUDY SELECTION AND DATA EXTRACTION

Relevant articles and abstracts, particularly of in vitro experiments and clinical studies, were compiled and reviewed.

DATA SYNTHESIS

ADRs, especially in HIV-infected patients, are a cause for concern. Sulfonamides, anticonvulsants, and antimycobacterial drugs are commonly used to prevent and treat complications of HIV, including seizures and opportunistic infections. Patients with HIV have a much greater rate of ADRs to these drug classes, including severe and life-threatening hypersensitivity reactions. Several mechanisms of these ADRs have been postulated. Sulfamethoxazole and anticonvulsant hypersensitivity may involve the increased formation and decreased detoxification of reactive metabolites. The mechanisms for the marked increase in hypersensitivity ADRs to antimycobacterial drugs may be related to an altered immune profile in patients infected with both tuberculosis and HIV.

CONCLUSIONS

ADRs to antimicrobial and anticonvulsant therapy cause markedly increased morbidity and mortality in HIV-positive patients. Further research involving the interaction between HIV and the increased ADRs to these drugs is required.

Hypersensitivity of HIV-1-Infected Cells to Reactive Sulfonamide Metabolites Correlated to Expression of the HIV-1 Viral Protein Tat

Impairment of human immunodeficiency virus (HIV)-infected cells to deal with reactive drug metabolites may be a mechanism for the increased rate of adverse drug reactions seen in AIDS. HIV Tat protein expression may be associated with increased oxidative stress within HIV-infected cells. To determine the relationship between expression of HIV Tat and sensitivity to reactive drug metabolites, we studied toxicity of sulfamethoxazole (SMX) and its reactive hydroxylamine intermediate (SMX-HA) in lymphocytes transfected with the HIV tat gene. Over a concentration range from 0 to 400 microM SMX-HA, there was a significant concentration-dependent increase in cell death in transfected cell lines expressing Tat compared with controls. Jurkat T cells transfected with a dose-dependent inducible tat gene showed increased toxicity in response to SMX-HA as more Tat expression was induced. Enhanced sensitivity to SMX-HA was accompanied by significantly lower concentrations of total intracellular glutathione compared with controls (P < 0.05). Sensitivity to reactive drug metabolites in HIV-infected cells seems to be mediated by the viral protein Tat.

Antiparasitic therapy in children

Treatment of parasitic infections in children presents many challenges for the clinician. Although parasitic infections are ubiquitous on a worldwide basis, with an estimated 1 billion persons infected with intestinal helminthes alone, physicians in the United States and other developed countries are often unfamiliar with the management of these diseases. Children are traveling internationally in larger numbers than ever before, however, and emigration from developing countries to the United States and other Western countries is increasing, so clinicians in these countries are confronted more frequently with parasitic diseases from the tropics. This article describes current approaches to antiparasitic therapy. Drugs used in the treatment of more than one type of parasite are presented once in detail, with reference to the detailed description in subsequent sections.

Genotoxicity studies on the antimicrobial drug sulfamethoxazole in cultured human lymphocytes

The genotoxicity of the antimicrobial drug sulfamethoxazole was evaluated in cultured human peripheral blood lymphocytes. The frequencies of sister-chromatid exchange (SCE) and micronuclei (MN) were scored as genetic endpoints. Both tests cover a wide range of induced genetic damage such as primary DNA damage, clastogenicity and aneugenicity. Cultures were set up with blood samples from two healthy donors and the treatment was done with different sulfamethoxazole concentrations ranging from 10 to 500 microg/ml. From the results obtained it appears that this drug is able to induce weak genotoxic effects, as revealed by the slight increase in the SCE and MN frequencies, at least at one of the two highest concentrations tested. However, the results of the SCE assay should be interpreted with caution because the increase is just significant. In addition, cyotoxic/cytostatic effects of sulfamethoxazole were revealed by a decrease in the proliferative rate index (PRI) and in the cytokinesis block proliferation index (CBPI).

ADVERSE REACTIONS OF NITROFURANTOIN, TRIMETHOPRIM AND SULFAMETHOXAZOLE IN CHILDREN

PURPOSE

Many children with urological disease require long-term treatment with antibiotics. In many cases the choice of medical instead of surgical management hinges on the implied safety of certain drugs. Recently some groups have advocated subureteral injection procedures to avoid long-term antibiotics for low grade reflux. We present a concise and relevant review on the use and adverse reactions of nitrofurantoin, trimethoprim and sulfamethoxazole in children.

MATERIALS AND METHODS

We reviewed the literature regarding the safety and toxicity of these drugs. Information regarding absorption, excretion and dosing was also gathered to explain better the mechanisms of toxicity.

RESULTS

Adverse reactions in children reported in the literature related to nitrofurantoin are gastrointestinal disturbance (4.4/100 person-years at risk), cutaneous reactions (2% to 3%), pulmonary toxicity (9 patients), hepatoxicity (12 patients and 3 deaths), hematological toxicity (12 patients), neurotoxicity and an increased rate of sister chromatid exchanges. Adverse reactions in children related to trimethoprim/sulfamethoxazole are almost exclusively due to the sulfamethoxazole component, including cutaneous reactions (1.4 to 7.4 events per 100 person-years at risk), hematological toxicity (0% to 72% of patients) and hepatotoxicity (5 patients). The majority of adverse reactions were found in children on full dose therapy and not prophylaxis.

CONCLUSIONS

The use of nitrofurantoin, trimethoprim and sulfamethoxazole is safe in children for long-term prophylactic therapy. The antibiotic safety issue should not be misconstrued as an argument for surgical therapy, whether minimally invasive or not. Adverse reactions exist to these medicines but they are less common than seen in adults, presumably because of the lower dose used for therapy, and the lack of significant comorbidities and drug interactions in children. Serious side effects are extremely rare and most are reversible by discontinuing therapy. The extremely low potential for significant adverse reactions should be discussed with parents.

Opportunistic infections and other clinical manifestations of HIV disease in children

As the decade draws to a close, physicians can be cautiously optimistic about the prevention and treatment of opportunistic infections in children with HIV disease. As more children receive therapy with powerful antiretroviral regimens, fewer are likely to be at risk for opportunistic pathogens. The widespread use of protease inhibitor combination therapies has already resulted in a dramatic decrease in morbidity and mortality in the population of HIV-infected adults. The same effect has been seen at pediatric care centers throughout the United States. Clinicians caring for HIV-infected children are now considering the safety of discontinuing prophylactic therapies for children with sustained immunologic improvement on antiretroviral therapy. For children who remain at risk, prophylactic regimens for PCP and MAC have been shown to decrease the risk for these infections. Preventive regimens for several other opportunistic infections are also available. The understanding of the pathogenesis of HIV and many of the opportunistic pathogens has led to the development of a variety of efficacious therapies for these infections. Despite these advances, physicians can anticipate that HIV-infected children will continue to develop opportunistic infections and other related complications. Some children fail to respond to antiretroviral therapies, whereas others are unable to tolerate the complex medication regimens. Prophylactic therapies are not 100% protective and, despite improved treatments, few opportunistic infections are cured. Most require lifelong maintenance therapy in the absence of immune reconstitution. Drug interactions, complex dosing schedules, adverse side effects, and high costs further limit the efficacy of these therapies. The prophylaxis, diagnosis, and treatment of opportunistic infections are likely to remain integral components of HIV care for the near and distant future.

Cytotoxicity of sulfonamide reactive metabolites: apoptosis and selective toxicity of CD8(+) cells by the hydroxylamine of sulfamethoxazole

Treatment with sulfonamide antibiotics in HIV-infected patients is associated with a high incidence (> 40%) of adverse drug events, including severe hypersensitivity reactions. Sulfonamide reactive metabolites have been implicated in the pathogenesis of these adverse reactions. Sulfamethoxazole hydroxylamine (SMX-HA) induces lymphocyte toxicity and suppression of proliferation in vitro; the mechanism(s) of these immunomodulatory effects remain unknown. We investigated the cytotoxicity of SMX-HA via apoptosis on human peripheral blood mononuclear cells and purified cell subpopulations in vitro. CD19(+), CD4(+), and CD8(+) cells were isolated from human peripheral blood by positive selection of cell surface molecules by magnetic bead separation. SMX-HA induced significant CD8(+) cell death (67 +/- 7%) at 100 microM SMX-HA, with only minimal CD4(+) cell death (8 +/- 4%). No significant subpopulation toxicity was shown when incubated with parent drug (SMX). Flow cytometry measuring phosphatidylserine externalization 24 h after treatment with 100 microM and 400 microM SMX-HA revealed 14.1 +/- 0.7% and 25. 6 +/- 4.2% annexin-positive cells, respectively, compared to 3.7 +/- 1.2% in control PBMCs treated with 400 microM SMX. Internucleosomal DNA fragmentation was observed in quiescent and stimulated PBMCs 48 h after incubation with SMX-HA. Our data show that CD8(+) cells are highly susceptible to the toxic effects of SMX-HA through enhanced cell death by apoptosis.