Description

This product is a clear or almost clear, slightly viscous liquid.

Pharmacological Action

Pharmacodynamics：Ivermectin has good expelling and killing effects mainly against internal nematodes and external arthropods in animals. Its anthelmintic mechanism involves promoting the release of γ-aminobutyric acid (GABA) from presynaptic neurons, thereby opening GABA‑mediated chloride channels. Ivermectin also has a selective and high affinity for glutamate‑gated chloride channels located near GABA‑mediated sites in the nerves and muscle cells of invertebrates, thus interfering with signal transmission between nerves and muscles, causing flaccid paralysis of the parasites, leading to their death or expulsion from the host. The sites of action in nematodes are the inhibitory interneurons and excitatory motor neurons, while in arthropods the site of action is the neuromuscular junction. In cattle and sheep, the removal rate against adult worms and fourth‑stage larvae of Haemonchus, Ostertagia, Cooperia, Trichostrongylus (including T. axei), Nematodirus, Bunostomum, Nematodirus, Trichuris, Oesophagostomum, Dictyocaulus, and Chabertia in sheep is 97–100%. It is also very effective against arthropods such as fly larvae, mites, and lice. Efficacy against biting lice and the sheep ked is slightly lower. Ivermectin is also highly effective against ticks and flies that breed in feces; although it does not kill ticks immediately, it affects their feeding, molting, and egg‑laying, thereby reducing reproductive capacity. A similar effect is seen against blood‑sucking flies. In pigs, the removal rate against adult and immature stages of Ascaris suum, Stephanurus dentatus, Strongyloides ransomi, Trichuris suis, Oesophagostomum spp., Metastrongylus spp., and Stephanurus dentatus is 94–100%. It is also very effective against intestinal Trichinella spiralis (ineffective against muscle Trichinella), and provides good control of hog lice and sarcoptic mange mites. Ivermectin is ineffective against trematodes and cestodes.

Pharmacokinetics：The pharmacokinetics of ivermectin vary significantly among animal species, dosage forms, and routes of administration. Bioavailability after subcutaneous injection is higher than after oral administration, but oral administration results in faster absorption than subcutaneous injection. After absorption, it is well distributed to most tissues but does not readily enter the cerebrospinal fluid. The apparent volumes of distribution in cattle, sheep, and pigs are 0.45–2.4 L/kg, 4.6 L/kg, and 4 L/kg, respectively. The elimination half‑life is relatively long in most animals: 2–3 days in cattle, 2–7 days in sheep, and 0.5 days in pigs. The drug is metabolised in the liver; in cattle and sheep mainly by hydroxylation, and in pigs mainly by methylation. It is primarily excreted in the faeces, with less than 5% of the dose excreted unchanged or as metabolites in the urine. In lactating females, up to 5% of the administered dose is excreted in milk.

Action and Use

Macrolide antiparasitic agent. Used for the prevention and treatment of nematodosis, acariasis, and other parasitic insect diseases in domestic animals.

Dosage and Administration

Subcutaneous injection: single dose, per 1 kg body weight — cattle and sheep 0.02 ml; pigs 0.03 ml.

Adverse Reactions

(1) When used for the treatment of cattle warble fly larvae (hypodermosis), if the killed larvae are located in critical sites, severe adverse reactions may occur.

(2) During injection, there may be discomfort or temporary edema at the injection site.

Precautions

(1) For cattle and sheep producing milk for human consumption, do not use during the lactating period.

(2) At each subcutaneous injection site, the volume should not exceed 10 ml.

(3) Ivermectin is highly toxic to shrimp, fish, and aquatic organisms. Do not contaminate water sources with residual drug or packaging.

Withdrawal Period

Withdrawal period: cattle and sheep 35 days; pigs 28 days.

Specification

Calculated as ivermectin (H₂B_1a + H₂B_1b):

 (1) 1 ml : 10 mg

 (2) 2 ml : 20 mg

 (3) 5 ml : 50 mg

 (4) 10 ml : 100 mg

 (5) 50 ml : 500 mg

 (6) 100 ml : 1000 mg