Prevention of pneumocystis pneumonia in patients with hematological diseases: Efficacy of low-dose atovaquone.

OBJECTIVE: At our institution, patients with hematological disease who require Pneumocystis jirovecii pneumonia (PJP) prophylaxis were administered atovaquone at a low dose (750 mg/day). However, there have been few reports on the efficacy of low-dose atovaquone administration, and the purpose of this study is, therefore, to investigate its effectiveness. MATERIALS AND METHODS: We investigated the expression of PJP in patients with hematological disease who received atovaquone administration. Atovaquone was administered at a low dose of 750 mg once daily, and the follow-up time was the period of PJP prophylaxis that included atovaquone administration. RESULTS: 85 patients were included in the study. The median age of the study population was 72 years (range: 33 - 97). The duration of atovaquone treatment and follow-up time were 150 days (22 - 1,018) and 258 days (22 - 1,457), respectively. In hematologic diseases, multiple myeloma was high in 31 patients and malignant lymphoma in 28 patients. No patients exhibited PJP during the observation period. CONCLUSION: In hematological disease patients with relatively low risk of PJP, low-dose atovaquone may prevent the onset of PJP.

Symptoms of illness during travel and risk factors for non-adherence to malaria prophylaxis-a cross-sectional study in travellers from Germany.

BACKGROUND: Perceived adverse effects of antimalarial chemoprophylaxis can be difficult to distinguish from travel-related illness and are often cited as important reasons for non-adherence or refusal of antimalarial chemoprophylaxis. We aimed to investigate the occurrence of symptoms of illness in travellers with and without chemoprophylaxis in a cross-sectional study after travel and to identify risk factors for non-adherence to prophylaxis. METHODS: We enrolled 458 travellers to Africa and South America during their pre-travel medical consultation at the travel clinic of the University Medical Centre Hamburg-Eppendorf and conducted post-travel interviews on symptoms of illness and intake of malaria prophylaxis. RESULTS: Eleven percent (49/437) of the participants reported symptoms of illness during travel. In total, 36% (160/448) of the participants reported prescription of chemoprophylaxis, the vast majority of these travelled to Africa (98%) and received atovaquone/proguanil (93%). Frequency of symptoms did not differ significantly between participants without prophylaxis and those taking atovaquone/proguanil. Non-adherence to prophylaxis was frequent (20%), but only 3% (4/149) of the participants stopped the medication early because of perceived side effects. Risk factors associated with non-adherence to prophylaxis included age under 30 years, travel to West or Central Africa and travel duration greater than 14 days. CONCLUSIONS: Symptoms of illness during travel occurred at similar frequencies irrespective of intake of chemoprophylaxis. Travellers should be informed about chemoprophylaxis in a balanced way, without raising fear of side effects, especially among groups at higher risk for incorrect use of prophylaxis.

Comparative effectiveness of trimethoprim-sulfamethoxazole versus atovaquone for the prophylaxis of pneumocystis pneumonia in patients with connective tissue diseases receiving prolonged high-dose glucocorticoids.

We compared the prophylactic effect of trimethoprim-sulfamethoxazole (TMP-SMX) with atovaquone for pneumocystis pneumonia (PCP) in patients with connective tissue diseases (CTDs) receiving high-dose glucocorticoids. Patients with CTDs aged ≥ 18 years who were treated with a prolonged course (≥ 4 weeks) of glucocorticoids (≥ 20 mg/day prednisone) in a Japanese tertiary center between 2013 and 2017 were included. The patients were categorized into two groups: TMP-SMX and atovaquone group. Adjusted cumulative incidence of PCP was compared between the two groups after propensity score weighting for differences in confounding factors. A total of 480 patients with a prolonged high-dose glucocorticoid treatment were identified. Out of 383 patients with TMP-SMX prophylaxis, 102 (26.8%) patients experienced adverse events leading to discontinuation within 4 weeks of initiation, while no patient in the atovaquone discontinued the therapy. Two hundred eighty-one patients received TMP-SMX, while 107 received atovaquone for PCP prophylaxis. During a total of 397.0 person-years, 7 PCP cases (2 in the TMP-SMX, 5 in the atovaquone) occurred with a mortality rate of 54.5%. After adjusting for differences in baseline characteristics, the adjusted cumulative incidence of PCP was similar between the two group (HR 0.97, 95% CI 0.19-5.09, p = 0.97). Prophylactic effects for PCP in CTDs patients receiving prolonged high-dose glucocorticoids were similar between TMP-SMX and atovaquone. Atovaquone was well-tolerated with no side effects.

Safety and efficacy of hydroxyurea and eflornithine against most blood parasites Babesia and Theileria.

BACKGROUND: The plenteous resistance to and undesirable consequences of the existing antipiroplasmic therapies have emphasized the urgent need for new chemotherapeutics and drug targets for both prophylaxis and chemotherapy. Hydroxyurea (HYD) is an antineoplastic agent with antitrypanosomal activity. Eflornithine (α-difluoro-methyl ornithine, DFMO) is the best choice therapy for the treatment of late-stage Gambian human African trypanosomiasis. METHODS: In this study, the inhibitory and combination efficacy of HYD and DFMO with existing babesicidal drugs (diminazene aceturate (DA), atovaquone (ATV), and clofazimine (CLF)) deoxyribonucleotide in vitro against the multiplication of Babesia and Theileria. As well as, their chemotherapeutic effects were assessed on B. microti strain that infects rodents. The Cell Counting Kits-8 (CCK-8) test was used to examine their cytotoxicity on human foreskin fibroblast (HFF), mouse embryonic fibroblast (NIH/3T3), and Madin-Darby bovine kidney (MDBK) cells. FINDINGS: HYD and DFMO suppressed the multiplication of all tested species (B. bigemina, B. bovis, B. caballi, B. divergens, and T. equi) in a dose-related manner. HFF, NIH/3T3, or MDBK cell viability was not influenced by DFMO at 1000 µM, while HYD affected the MDBK cell viability at EC50 value of 887.5±14.4 µM. The in vitro combination treatments of DFMO and HYD with CLF, DA, and ATV exhibited synergistic and additive efficacy toward all tested species. The in vivo experiment revealed that HYD and DFMO oral administration at 100 and 50 mg/kg inhibited B. microti multiplication in mice by 60.1% and 78.2%, respectively. HYD-DA and DFMO-DA combined treatments showed higher chemotherapeutic efficacy than their monotherapies. CONCLUSION: These results indicate the prospects of HYD and DFMO as drug candidates for piroplasmosis treatment, when combined mainly with DA, ATV, and CLF. Therefore, further studies are needed to combine HYD or DFMO with either ATV or CLF and examine their impact on B. microti infection in mice.

Malarone® induced pancreatitis and alopecia in a dog: a case report.

BACKGROUND: Malarone® is a drug used for the treatment of malaria in humans. This drug is also particularly effective in the treatment of canine Babesia gibsoni infections. Malarone® is rarely used in dogs, and its adverse effects have not been widely reported. Its mechanism of action is related to the inhibition of cytochrome b and electron transport in the cell. This is the first known report of the development of acute pancreatitis and alopecia in a dog following the administration of Malarone®. CASE PRESENTATION: A 3-year-old, intact, female Maltese was referred to our clinic with intermittent vomiting and sudden, generalized alopecia. Two months previously, the dog had been prescribed Malarone® for the treatment of a suspected B. gibsoni infection. The dog was evaluated using hematology, radiography, ultrasonography, a PCR for Babesia detection, and a canine pancreatic lipase immunoreactivity (cPLI) assay. The result of the PCR test was negative, whereas the cPLI assay yielded a positive result. Dermatologic examination revealed bacterial infection with hair cycle arrest. CONCLUSIONS: Based on these findings, drug-induced acute pancreatitis and alopecia with superficial pyoderma were diagnosed. Malarone® may induce severe adverse reactions in dogs. Therefore, careful monitoring for adverse effects is required when using Malarone® in dogs.

The safety of atovaquone-proguanil for the prevention and treatment of malaria in pregnancy: A systematic review.

BACKGROUND: Malaria infection poses a significant risk in pregnancy, yet chemoprophylaxis for pregnant women is limited. A systematic review was conducted to evaluate the incidence of adverse outcomes after atovaquone-proguanil (AP) exposure during pregnancy. METHODS: Following PRISMA guidelines, the authors searched PubMed, MEDLINE, and the Malaria in Pregnancy Consortium Library to identify relevant literature including infant outcomes after exposure to atovaquone, proguanil, or AP in pregnancy. Two authors independently screened the titles, abstracts, and full texts, and extracted data into an EpiInfo database. Overall proportions and 95% confidence intervals of adverse outcomes were determined by pooling data across studies. RESULTS: Of 455 records identified, 16 studies were included: ten AP studies and six proguanil studies. The overall proportions and 95% confidence intervals (CI) of adverse outcomes reported for the 446 women exposed to AP include miscarriage (8.08% CI: 5.07, 12.08%), stillbirth (1.05% CI: 0.03, 5.73%), early neonatal death (0% CI: 0, 7.4%), and congenital anomalies (2.56% CI: 1.28, 4.53%). CONCLUSIONS: The limited available data suggest that outcomes following AP exposure during pregnancy are similar to expected rates in similar populations. AP may be a promising option for pregnant women, but further data are needed on its safety in pregnancy.

Safety of atovaquone-proguanil during pregnancy.

BACKGROUND: Malaria during pregnancy increases the risk of maternal and foetal complications. There are very limited options for prophylaxis in pregnant travellers. Atovaquone-Proguanil (AP or Malarone®) is an effective and well-tolerated antimalarial medication, but is not recommended for use in pregnancy due to limited data on safety. Passively reported adverse event data may provide additional information on the safety of AP during pregnancy. METHODS: We analysed adverse event data on pregnancy and birth outcomes following accidental exposures to AP during pregnancy, which were passively reported to GlaxoSmithKline LLC (GSK) between 13 May 1997 and 15 August 2017. Birth outcomes of interest included live birth, miscarriage, and stillbirth. Adverse outcomes of interest were defined as any of the following: small for gestational age (SGA), low birth weight (LBW, <2500 gm), congenital anomalies, and a composite 'poor live birth outcome,' including preterm birth (PTB), LBW or SGA. RESULTS: Among 198 women who received AP during pregnancy or breastfeeding, 96.5% occurred in women taking malaria prophylaxis, and 79.8% of exposures occurred in the first trimester. Among 195 with available birth outcome data, 18.5% resulted in miscarriage and 11.8% were elective terminations. Available adverse outcomes included SGA in 3.5% (3/85), LBW in 7.0% of infants (6/86), and the composite 'poor live birth outcome' in 13.7% (14/102). Congenital anomalies were reported in 30/124 (24.2%), with no specific pattern to suggest an effect related to AP. CONCLUSIONS: These data provide a description of outcomes in the pregnancies reported to this dataset, and it should be noted that there is likely a bias towards reporting cases resulting in poor outcomes. While there was no specific signal to suggest a teratogenic effect of AP, AP data during pregnancy were too limited to determine AP's safety with confidence. As inadvertent exposures are not infrequent, better data are needed.

Managing emerging mutagenicity risks: Late stage mutagenic impurity control within the atovaquone second generation synthesis.

The mutagenic-impurity control strategy for a second generation manufacturing route to the non-mutagenic antipneumocystic agent atovaquone (2-((1R,4R)-4-(4-chlorophenyl)cyclohexyl)-3-hydroxynaphthalene-1,4-dione) 1 is described. Preliminary assessment highlighted multiple materials of concern which were largely discharged either through returning a negative bacterial mutagenicity assay or through confidence that the impurity would be purged during the downstream processing from when it was first introduced. Additional genotoxicity testing highlighted two materials of concern where initial assessment suggested that testing for these impurities at trace levels within the drug substance would be required. Following a thorough review of process purging detail, spiking and purging experimentation, and an understanding of the process parameters to which they were exposed an ICH M7 Option 4 approach could be justified for their control. The development of two 1H NMR spectroscopy methods for measurement of these impurities is also described as well as a proposed summary table for describing the underlying rationale for ICH M7 control rationales to regulators. This manuscript demonstrates that process purging of potential mutagenic impurities can be realised even when they are introduced in the later stages of a process and highlights the importance of scientific understanding rather than relying on a stage-counting approach.

A survey on outcomes of accidental atovaquone-proguanil exposure in pregnancy.

BACKGROUND: Malaria chemoprophylaxis options in pregnancy are limited, and atovaquone-proguanil (AP) is not recommended because of insufficient safety evidence. An anonymous, internet-based survey was disseminated to describe outcomes of pregnancies accidentally exposed to AP. Outcomes of interest included miscarriage (defined as pregnancy loss before 20 weeks), stillbirth (defined as pregnancy loss at or after 20 weeks), preterm birth or live birth prior to 37 weeks, and the presence of congenital anomalies. RESULTS: A total of 487 women responded and reported on 822 pregnancies. Of the 807 pregnancies with information available on exposure and outcomes, 10 (1.2%) had atovaquone-proguanil exposure, all in the first trimester, and all resulted in term births with no birth defects. CONCLUSIONS: Use of an anti-malarial not recommended in pregnancy is likely to occur before the woman knows of her pregnancy. This study adds to the limited evidence of the safety of AP in pregnancy. Further study on use of AP in pregnancy should be a high priority, as an alternative option for the prevention of malaria in pregnancy in non-immune travellers is urgently needed.

Mefloquine for preventing malaria during travel to endemic areas.

BACKGROUND: Mefloquine is one of four antimalarial agents commonly recommended for preventing malaria in travellers to malaria-endemic areas. Despite its high efficacy, there is controversy about its psychological side effects. OBJECTIVES: To summarize the efficacy and safety of mefloquine used as prophylaxis for malaria in travellers. SEARCH METHODS: We searched the Cochrane Infectious Diseases Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), published on the Cochrane Library; MEDLINE; Embase (OVID); TOXLINE (https://toxnet.nlm.nih.gov/newtoxnet/toxline.htm); and LILACS. We also searched the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP; http://www.who.int/ictrp/en/) and ClinicalTrials.gov (https://clinicaltrials.gov/ct2/home) for trials in progress, using 'mefloquine', 'Lariam', and 'malaria' as search terms. The search date was 22 June 2017. SELECTION CRITERIA: We included randomized controlled trials (for efficacy and safety) and non-randomized cohort studies (for safety). We compared prophylactic mefloquine with placebo, no treatment, or an alternative recommended antimalarial agent. Our study populations included all adults and children, including pregnant women. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed the eligibility and risk of bias of trials, extracted and analysed data. We compared dichotomous outcomes using risk ratios (RR) with 95% confidence intervals (CI). Prespecified adverse outcomes are included in 'Summary of findings' tables, with the best available estimate of the absolute frequency of each outcome in short-term international travellers. We assessed the certainty of the evidence using the GRADE approach. MAIN RESULTS: We included 20 RCTs (11,470 participants); 35 cohort studies (198,493 participants); and four large retrospective analyses of health records (800,652 participants). Nine RCTs explicitly excluded participants with a psychiatric history, and 25 cohort studies stated that the choice of antimalarial agent was based on medical history and personal preference. Most RCTs and cohort studies collected data on self-reported or clinician-assessed symptoms, rather than formal medical diagnoses. Mefloquine efficacyOf 12 trials comparing mefloquine and placebo, none were performed in short-term international travellers, and most populations had a degree of immunity to malaria. The percentage of people developing a malaria episode in the control arm varied from 1% to 82% (median 22%) and 0% to 13% in the mefloquine group (median 1%).In four RCTs that directly compared mefloquine, atovaquone-proguanil and doxycycline in non-immune, short-term international travellers, only one clinical case of malaria occurred (4 trials, 1822 participants). Mefloquine safety versus atovaquone-proguanil Participants receiving mefloquine were more likely to discontinue their medication due to adverse effects than atovaquone-proguanil users (RR 2.86, 95% CI 1.53 to 5.31; 3 RCTs, 1438 participants; high-certainty evidence). There were few serious adverse effects reported with mefloquine (15/2651 travellers) and none with atovaquone-proguanil (940 travellers).One RCT and six cohort studies reported on our prespecified adverse effects. In the RCT with short-term travellers, mefloquine users were more likely to report abnormal dreams (RR 2.04, 95% CI 1.37 to 3.04, moderate-certainty evidence), insomnia (RR 4.42, 95% CI 2.56 to 7.64, moderate-certainty evidence), anxiety (RR 6.12, 95% CI 1.82 to 20.66, moderate-certainty evidence), and depressed mood during travel (RR 5.78, 95% CI 1.71 to 19.61, moderate-certainty evidence). The cohort studies in longer-term travellers were consistent with this finding but most had larger effect sizes. Mefloquine users were also more likely to report nausea (high-certainty evidence) and dizziness (high-certainty evidence).Based on the available evidence, our best estimates of absolute effect sizes for mefloquine versus atovaquone-proguanil are 6% versus 2% for discontinuation of the drug, 13% versus 3% for insomnia, 14% versus 7% for abnormal dreams, 6% versus 1% for anxiety, and 6% versus 1% for depressed mood. Mefloquine safety versus doxycyclineNo difference was found in numbers of serious adverse effects with mefloquine and doxycycline (low-certainty evidence) or numbers of discontinuations due to adverse effects (RR 1.08, 95% CI 0.41 to 2.87; 4 RCTs, 763 participants; low-certainty evidence).Six cohort studies in longer-term occupational travellers reported our prespecified adverse effects; one RCT in military personnel and one cohort study in short-term travellers reported adverse events. Mefloquine users were more likely to report abnormal dreams (RR 10.49, 95% CI 3.79 to 29.10; 4 cohort studies, 2588 participants, very low-certainty evidence), insomnia (RR 4.14, 95% CI 1.19 to 14.44; 4 cohort studies, 3212 participants, very low-certainty evidence), anxiety (RR 18.04, 95% CI 9.32 to 34.93; 3 cohort studies, 2559 participants, very low-certainty evidence), and depressed mood (RR 11.43, 95% CI 5.21 to 25.07; 2 cohort studies, 2445 participants, very low-certainty evidence). The findings of the single cohort study reporting adverse events in short-term international travellers were consistent with this finding but the single RCT in military personnel did not demonstrate a difference between groups in frequencies of abnormal dreams or insomnia.Mefloquine users were less likely to report dyspepsia (RR 0.26, 95% CI 0.09 to 0.74; 5 cohort studies, 5104 participants, low certainty-evidence), photosensitivity (RR 0.08, 95% CI 0.05 to 0.11; 2 cohort studies, 1875 participants, very low-certainty evidence), vomiting (RR 0.18, 95% CI 0.12 to 0.27; 4 cohort studies, 5071 participants, very low-certainty evidence), and vaginal thrush (RR 0.10, 95% CI 0.06 to 0.16; 1 cohort study, 1761 participants, very low-certainty evidence).Based on the available evidence, our best estimates of absolute effect for mefloquine versus doxycyline were: 2% versus 2% for discontinuation, 12% versus 3% for insomnia, 31% versus 3% for abnormal dreams, 18% versus 1% for anxiety, 11% versus 1% for depressed mood, 4% versus 14% for dyspepsia, 2% versus 19% for photosensitivity, 1% versus 5% for vomiting, and 2% versus 16% for vaginal thrush.Additional analyses, including comparisons of mefloquine with chloroquine, added no new information. Subgroup analysis by study design, duration of travel, and military versus non-military participants, provided no conclusive findings. AUTHORS' CONCLUSIONS: The absolute risk of malaria during short-term travel appears low with all three established antimalarial agents (mefloquine, doxycycline, and atovaquone-proguanil).The choice of antimalarial agent depends on how individual travellers assess the importance of specific adverse effects, pill burden, and cost. Some travellers will prefer mefloquine for its once-weekly regimen, but this should be balanced against the increased frequency of abnormal dreams, anxiety, insomnia, and depressed mood.

Efficacy, safety and tolerance of imidocarb dipropionate versus atovaquone or buparvaquone plus azithromycin used to treat sick dogs naturally infected with the Babesia microti-like piroplasm.

BACKGROUND: Piroplasmosis caused by the Babesia microti-like piroplasm (Bml) is increasingly being detected in dogs in Europe. Sick dogs show acute disease with severe anaemia associated with thrombocytopenia with a poor response to current available drugs. This study assesses the safety and tolerance of three treatments and compares their efficacy over a full year of follow up in dogs naturally infected with Bml. METHODS: Fifty-nine dogs naturally infected with Bml were randomly assigned to a treatment group: imidocarb dipropionate (5 mg/kg SC, 2 doses 14 d apart) (IMI); atovaquone (13.3 mg/kg PO q 8 h, 10 d)/azithromycin (10 mg/kg PO q 24 h, 10 d) (ATO); or buparvaquone (5 mg/kg IM, 2 d apart)/azithromycin (same dosage) (BUP). Before and after treatment (days 15, 45, 90 and 360), all dogs underwent a physical exam, blood tests and parasite detection (blood cytology and PCR). Clinical efficacy was assessed by grading 24 clinical and 8 clinicopathological signs from low to high severity. RESULTS: Before treatment, most dogs had severe regenerative anaemia (88.13%) and thrombocytopenia (71.4%). On treatment Day 45, clinical signs were mostly reduced in all dogs, and by Day 90, practically all dogs under the ATO or BUP regimen were clinically healthy (76.4 and 88%, respectively). Highest percentage reductions in laboratory abnormalities (82.04%) were detected in animals treated with ATO. Over the year, clinical relapse of Bml was observed in 8 dogs (8/17) treated with IMI. However, on Day 360, these animals had recovered clinically, though clinicopathological abnormalities were still present in some of them. Parasitaemia was PCR-confirmed on Days 90 and 360 in 47.05 and 50% of dogs treated with ATO, 68 and 60.08% with BUP, and 94.1 and 73.3% with IMI, respectively. Even after 360 days, 13.3% of the dogs treated with IMI returned a positive blood cytology result. CONCLUSIONS: IMI showed the worse clinical and parasitological, efficacy such that its use to treat Bml infection in dogs is not recommended. The treatments ATO and BUP showed better efficacy, though they were still incapable to completely eliminate PCR-proven infection at the recommended dose. All three treatments showed good tolerance and safety with scarce adverse events observed.

Malaria protection in Sierra Leone during the Ebola outbreak 2014/15; The UK military experience with malaria chemoprophylaxis Sep 14-Feb 15.

BACKGROUND: The UK deployed a task force to Sierra Leone to assist in ending the 2014/15 Ebola outbreak. Malaria protection was based on existing Defence Policy which saw a wide range of bite prevention measures deployed. Atovaquone/Proguanil ("A/P"), Doxycycline ("D") and Mefloquine ("M") were the chemoprophylactic medications that were prescribed. A survey was undertaken to audit the Adverse Effect (AE) burden experienced by the population. METHOD: A questionnaire based survey was administered that sought information on individuals' experiences with malaria chemoprophylaxis. RESULTS: 337 personnel were eligible to take part and 151 (46.3%) individuals returned questionnaires. The reported AE rates for the three drugs were "A/P" 28% of the respondents, "D" 25% and "M" 23.1%. 24 individuals (15.9%) reported 1 AE while 34 (22.5%) reported multiple AEs. Eight (5.3%) individuals changed medication (Five "A/P", two "M" and one "D") because of unacceptable AE but no significant neuro/psychological conditions were reported. The malaria attack rate for the deployed population was 0.4 cases per thousand person weeks which is very low when compared to other military deployments to the West African Area. CONCLUSION: UK Defence policy is effective in the way it balances the risk of malaria with that of AE due to chemoprophylaxis. "M" remains an acceptable chemoprophylactic agent for a section of the population.