Parasites
Thomas T. Yoshikawa, Shobita Rajagopalan in Antibiotic Therapy for Geriatric Patients, 2005
In this selective review, we will emphasize the parasitic differential diagnoses of common clinical manifestations, i.e., fever, eosinophilia, and rash, affecting individuals including the elderly who have recently traveled to the developing world. Detailed information regarding specific parasitic diseases may be reviewed from the suggested reading section provided at the end of this chapter. Although the incidence of many of these parasitic illnesses among older travelers is unknown, surveillance systems, i.e., GeoSentinel, from the International Society of Travel Medicine and the Centers for Disease Control and Prevention, and TropNetEurop, the European Network on Imported Infectious Disease Surveillance, are beginning to yield more information. The pharmacotherapy of parasitic infections is discussed in Chapter 26: Antiparasitic Drugs.
Determination
David Woolley, Adam Woolley in Practical Toxicology, 2017
For veterinary pharmaceuticals, the guideline places emphasis on veterinary medicinal products that will be used in food-producing animals that may not be individual treatments but may, for example, be used for treating a whole herd or flock. A tacit assumption is made that a substance that is extensively metabolized will not enter the environment. Separate consideration is given to substances used in the aquatic environment, which may enter the wider aquatic environment and those in terrestrial situations. Questions asked in the guideline include one about antiparasitic compounds, which may be a reaction in part to the environmental effects of ivermectin. Antiparasitic agents–but not those acting against protozoans–advance automatically to phase II. If the concentration at which the product enters the aquatic environment is calculated to be less than 1 μg/L or the PECsoil is expected to be less than 100 μg/kg, environmental evaluation of the product may stop at phase I.
The Application of Fragment-based Approaches to the Discovery of Drugs for Neglected Tropical Diseases
Venkatesan Jayaprakash, Daniele Castagnolo, Yusuf Özkay in Medicinal Chemistry of Neglected and Tropical Diseases, 2019
Blaazer et al. (2015) screened a commercially available library of 1040 fragments (with slightly higher molecular weight and complexity than a rule-of-three compliant fragment library) against T. brucei PDEB1 (TbPDEB1) using a luminescence-based biochemical assay. In parallel, fragments were tested against a human PDE (PDE4D) in order to facilitate prioritization of fragment hits selective for the parasite enzyme. A set of twelve fragments that inhibit TbPDEB1 by more than 90% at a concentration of 200 μM was identified in the screen, as was a set of seven fragments that show selectivity for TbPDEB1 over human PDE4D. Blaazer et al. (2015) focused on a set of four fragment hits (Table 1) that shared similarity with the scaffolds of known drugs. These fragments, along with analogues of each chosen from in-house libraries of drug-like compounds, were then tested for whole-cell activity against a panel of parasites (T. brucei, T. cruzi, Leishmania infantum and Plasmodium falciparum) as well as human cells. The two fragment hits with the highest molecular weight (which share a biphenyl core) showed antiparasitic activity against multiple parasites, as did a number of analogues. Two analogues (Table 1) with improved antiparasitic activity (meeting or surpassing that of benznidazole and miltefosine against T. cruzi and L. infantum, respectively) and selectivity are under further investigation (Blaazer et al. 2015). Whether the antiparasitic effect of these compounds is a consequence of PDE inhibition remains to be reported.
Nanoparticles for antiparasitic drug delivery
Published in Drug Delivery, 2019
Yuzhu Sun, Dongmei Chen, Yuanhu Pan, Wei Qu, Haihong Hao, Xu Wang, Zhenli Liu, Shuyu Xie
Chemical antiparasitic drugs are mainly used for controlling parasitic diseases. They are critical in animal husbandry development and animal health safety, but most antiparasitic drugs have low bioavailability due to their insolubility and their short half-life. Therefore, the treatment of parasitic diseases needs frequent dosage for a long-time because of the long-life cycles of parasites. The repeated treatment might cause animal stress, big labor intensity of farmer and drug resistance (Vercruysse et al., 2007). For example, praziquantel is hardly soluble in aqueous solution and its bioavailability is poor regarding its natural metabolism in the liver and rapid elimination from the body. The repeated high doses for a long time are required in the treatment of cestode infection and thus might result in dizziness, tiredness, nausea, and hangover sense.
Diagnostic and management strategies of ocular cysticercosis: current perspectives
Published in Expert Review of Ophthalmology, 2020
Focusing on diagnosis, the important step is the awareness of ophthalmologist. There are many available tools that can help presumptive diagnosis of ocular cysticercosis. The imaging investigation might show ocular cystic lesion. Nevertheless, the only method to get definitive diagnosis is the histopathology examination on surgical removal specimen of the cyst. In endemic area, most of the ocular cystic lesions are usually ocular cysticercosis. Nevertheless, surgical removal is sometimes difficult and might be selected as the first choice for diagnostic approach. If the diagnosis is made, the proper management is a challenge. If it is possible, the first choice should be surgical removal. With improved ocular surgery techniques, the surgical removal of ocular cysticercosis is considered safe and effective. Early treatment is preferred since delayed treatment might result in an extension of pathological lesion. Similar to any ocular surgery, the complication might occur. The good preoperative evaluation and good operative preparation are necessary for success in treatment of the patient. In addition to surgical approach, the antiparasitic drug must be concurrently used for curative treatment. The antiparasitic drug can help getting rid of the parasitic infection that might be hidden in any other organs of the patient.
Signal peptide peptidase: a potential therapeutic target for parasitic and viral infections
Published in Expert Opinion on Therapeutic Targets, 2022
Christopher Schwake, Michael Hyon, Athar H. Chishti
Parasitic infections continue to cause severe health and economic burden in regions where transmission is endemic. Drug resistance, ineffective standards of therapy, lack of new therapeutics in the pipeline, and cost of treatment prevent affected regions from containing transmission and treating people afflicted with these diseases. Given that we have identified SPP as a new target for future therapy, efforts should be focused to understand the efficacy of these drugs in inhibiting SPP. This approach would prove to be cost-effective and pragmatic for the treatment of many neglected tropical diseases across the world. Aspartyl proteases used in HIV therapy are not without adverse effects, but considering the potentially high risks for mortality from these disease with few alternative options, repurposing known drugs with established safety and efficacy profiles is a logical next step. HIV protease inhibitors have been shown to be effective against malaria, Babesia, and Trypanosoma infections. Unlike P. falciparum, a major challenge for screening large libraries of therapeutic compounds against B. microti remains with the lack of continuous in vitro culture systems to facilitate identification of promising hits for further development. Development of parasite-specific SPP inhibitors would provide a new class of antiparasitic compounds to regions where effective treatments remain elusive.
Related Knowledge Centers
- Amoeba
- Antibiotic
- Antifungal
- Bacteria
- Microsporum
- Parasitic Disease
- Medication
- Parasitic Worm
- Antimicrobial
- Oral Administration