Ivermectin Pharmacokinetics, pdf version: www.vf.uni-lj.si
Ivermectin Pharmacokinetics, html version: www.vf.uni-lj.si
Summary of Ivermectin Pharmacokinetics Study
* “Pharmacokinetics” is the study of the bodily absorption, distribution, metabolism, and excretion of drugs.
- Ivermectin levels in blood plasma and milk of various animal species were studied.
- Ivermectin’s effects are influenced by
- its formulation
- the route of administration (subcutaneous, oral, topical)
- the species of animal it's administered to
- the sex of the animal
- the physiological status of the animal (lactating, etc.)
- Antiparasitic efficacy is reflected by the blood plasma concentration levels of Ivermectin.
- Ivermectin blood plasma levels increase with an increase in the dose administered.
- Water-free injection formulations of Ivermectin have a longer duration of clinical efficacy.
- In oral formulations, bioavailability of Ivermectin is greater when using a micelle* solution compared to an oral paste. * A “micelle” is a colloidal aggregate of surfactant molecules. (Micelle solutions of Ivermectin are given to horses via tubes that go up through the nose and into the stomach.)
- There were significant differences in Ivermectin’s bioavailability and biological half-life between oral and subcutaneous administrations.
- Ivermectin’s blood plasma concentrations were lower after oral administration so systemic bioavailability and duration of antiparasitic action was decreased.
- Blood plasma concentration levels of Ivermectin were measurable for a longer period of time after a subcutaneous injection.
- Food fed to animals after they received an oral administration of Ivermectin caused the Ivermectin to adsorb to the food. It is recommended that oral Ivermectin be given on an empty stomach.
- Greatest bioavailability of Ivermectin is achieved first using subcutaneous administration, followed by oral then topical administration. However, Ivermectin residues were detected for a longer period of time after topical administration than after oral administration.
- Ivermectin in blood plasma was 3x greater after subcutaneous administration at a dose of 0.2 mg/kg body weight than after topical (pour-on) administration at a dose of 0.5 mg/kg body weight. However, because of its slow and continuous absorption, it is thought that Ivermectin would still be effective after topical administration.
- Ivermectin was detected in the blood plasma of guinea pigs after a subcutaneous administration of a dose of 0.5 mg/kg body weight. (The maximum blood plasma concentration was 0.7 ng/ml, which was the smallest value of all the animal species investigated.)
- Ivermectin is excreted into milk. However, the Ivermectin blood plasma levels of the suckling animals were very small. The indirect, oral ingestion of Ivermectin via the milk was considered negligible.
"The effect of food was observed in horses. Feeding immediately after an oral administration of ivermectin resulted in the drug's adsorption onto the food, consequently oral administration on an empty stomach is recommended." (Page 3 of the original study)
Guinea pigs (and rabbits) require a constant supply of food in their digestive systems. Fasting can have negative consequences. Do not deprive your pet of food for any length of time.
Originally posted: http://www.guinealynx.info/forums/viewtopic.php?p=152306#152306
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