Parasitology Treatments PDF

PARASITOLOGY 3 4 Parasitology Diagnostics Treatments Dr. Cassan Pulaski Learning Objectives: Students will be able to describe generic antiparasitic drugs classes commonly used in veterinary medicine (antiprotozoals, anthelmintics, insecticides, acaricide...

PARASITOLOGY 3 4 Parasitology Diagnostics Treatments Dr. Cassan Pulaski Learning Objectives: Students will be able to describe generic antiparasitic drugs classes commonly used in veterinary medicine (antiprotozoals, anthelmintics, insecticides, acaricides) with emphasis on specific indications and selection. Students will be able to contrast attributes of antiparasitic drugs, including information on: use of drugs prophylactically and therapeutically. Students will be exposed to the topics of appropriate administration/application of drugs (PO, topical, injectable, etc.), off-label/extra-label/minor species use of these drugs, product withdrawal times in food animals, and issues of drug resistance. BUT FIRST, LET’S TALK ABOUT LIFE CYCLES… And a general review for Monday’s exam When we think about parasiticides, consider: What species am I treating? (what host ? ) Can I use that drug in the species? (when doubt in - look up/ask) Does it kill what I want it to? (i kills adult stage. e. vs. Carval Stage) Are there any contraindications? - ex. milk clearance time in food animals - ex. Shedding of P-faz in environment Lisoxazolene) Methods of Parasite Control Raise animals in parasite-free environment IMPOSSIBLE Administer parasite-specific vaccines Biological control – Ex: nematophagous fungi "Diowormer" - pass through animal then kill parasites in environment Other non-chemical means – Ex: bioactive forage Chemotherapy = Anthelmintics and Ectoparasiticides Extra-Label Drug Use Privilege of veterinary profession – Only permitted by or on the order of a veterinarian and only when a bona fide veterinarian-client-patient relationship exists and an appropriate medical diagnosis has been made – Ensure proper dosage, proper drug labeling, treatment records, and withdrawal times – Should use labeled product if available and equally efficacious – Does not matter if prescription or OTC May choose extra-label: – If no labeled drug for indication or labeled product failed (drug resistance) – If published data supports that application ↳ ex multi-drug. resistant hook – Cost is not considered an acceptable factor EXAMPLES: worms in dogs – In goats extra-label use is very common (in U S.. + most Few approved products approved for sheep but not goats -> adjust dose) – In dogs/cats all uncommon parasites Strategies For Parasiticide Use Therapeutic = Treatment – See it > treat it Prophylactic = Prevention – Don’t want to see it > treat to prevent Strategic = Control – Treat at strategically timed intervals to provide optimal control Categories of Parasiticides Endoparasiticide – Kills internal parasites Ectoparasiticide – Kills external parasites Endectocide – Kills both internal and external parasites – New term coined specifically for avermectin/milbemycin (macrocyclic lactone) drugs Ivermectin Categories of Parasiticides Antiprotozoals – Activity against protozoan parasites Anthelmintics – Activity against helminths (worms) Insecticides / Acaricides – Activity against arthropods (insects and/or arachnids) Antiprotozoals FePu Anthelmintics Categories of Anthelmintics Nematocides Flukicides Cestocides NOTE: some compounds may be in more than one category Anthelmintics Administration Route: Oral – Tablet, chewable – Liquid, drench – Paste, bolus, SR bolus – Mineral block, in water Topical – Pour-on, Spot-on Injection Frequency: Daily Monthly PRN Major Classes of Anthelmintcs: Benzimidazoles Avermectin/milbemycins (macrolide endectocides), Membrane Depolarizers Isoquinoline (praziquantel and epsiprantel) Cyclodepsipeptides (emodepside) Arsenicals Ectoparasiticides Activity against – ticks – mites – flies – fleas – lice May be applied to animal or to environment Examples of Ectoparasiticides Insecticides Acaricides Repellents Insect Growth Regulators Insect Development Inhibitors Synergists Many are used in both pet and agricultural (crop) settings Life cycle - Kill the adults Adulticide ↑ kill adult Life cycle - Kill the babies IGRs Insect Growth Regulators Ectoparasiticide Administration ANIMAL ENVIRONMENT Topical – foggers – Spot-on, Sprays – strips – dip – shampoo – premise sprays – collar – dusts/powders Systemic 1. Lifestyle – oral 2. Exposure to ectoparasites – parenteral 3. What is the client willing – topical to give? - difficulty to administer - packaging - smell 4. $$$ Questions? Exam Monday covers Parasitology Lectures 1-3