Praziquantel, marketed as Biltricide, is an anthelmintic used in humans and animals for the treatment of tapeworms and flukes. Specifically, it is effective against schistosoma, Clonorchis sinensis the fish tape worm Diphyllobothrium latum. Praziquantel works by causing severe spasms and paralysis of the worms' muscles. This paralysis is accompanied - and probably caused - by a rapid Ca 2+ influx inside the schistosome. Morphological alterations are another early effect of praziquantel. These morphological alterations are accompanied by an increased exposure of schistosome antigens at the parasite surface. The worms are then either completely destroyed in the intestine or passed in the stool. An interesting quirk of praziquantel is that it is relatively ineffective against juvenile schistosomes. While initially effective, effectiveness against schistosomes decreases until it reaches a minimum at 3-4 weeks. Effectiveness then increases again until it is once again fully effective at 6-7 weeks. Glutathione S-transferase (GST), an essential detoxification enzyme in parasitic helminths, is a major vaccine target and a drug target against schistosomiasis. Schistosome calcium ion channels are currently the only known target of praziquantel. The antibiotic rifampicin decreases plasma concentrations of praziquantel. Carbamazepine and phenytoin are reported to reduce the bioavailability of praziquantel. Chloroquine reduces the bioavailability of praziquantel. The drug cimetidine heightens praziquantel bioavailability.

Pyrantel is an anthelmintic, which acts as an agonist of nicotinic receptors (AChRs) of nematodes and exerts its therapeutic effects by depolarizing their muscle membranes. It is used to treat a number of parasitic worm infections. This includes ascariasis, hookworm infections, enterobiasis (pinworm infection), trichostrongyliasis and trichinellosis. Common adverse reactions include diarrhea, nausea, vomiting, dizziness, headache and somnolence.

Emodepside is a semi-synthetic product (originated by Astellas and out-licensed to Bayer for animal and human use); its precursor is synthesized by a fungus living in the leaves of Camellia japonica. It is a potent antihelminthic drug used in combination with praziquantel (as Profender®) and in combination with toltrazuril (as Procox®) for the treatment of parasitic worms in cats and dogs. Emodepside, a semi-synthetic derivative of PF1022A, belongs to a new class of anthelmintic drugs, the cyclooctadepsipeptides, and shows good efficacy against macrocyclic lactone-, levamisole- or benzimidazole-resistant nematode populations. Although putative receptors for emodepside have already been discovered, its mode of action is still not fully understood. It has being suggested that GABA(A)-receptor UNC-49 is associated with the emodepside mode of action. It has also being shown that Emodepside binds to a presynaptic latrophilin receptor in nematodes. The following presynaptic signal transduction occurs via activation of Gqalpha protein and phospholipase-Cbeta, which leads to mobilization of diacylglycerol (DAG). DAG then activates UNC-13 and synaptobrevin, two proteins which play an important role in presynaptic vesicle-functioning. This finally leads to the release of a currently unidentified transmitter. The transmitter (or modulator) exerts its effects at the postsynaptic membrane and induces a flaccid paralysis of the pharynx and the somatic musculature in nematodes.

Lufenuron is used to fight fungal infections, since fungus cell walls are about one third chitin. Lufenuron is the active ingredient in the veterinary flea control medication Program. FDA approved this drug for use in dogs and cats. Available by prescription. Once the female flea ingests blood from a pet treated with lufenuron, 96% of egg development from fleas on cats and 99% of egg development from fleas on dogs is stopped. This helps prevent a continual flea problem. Lufenuron does not kill the adult flea and does not stop the flea from biting and causing flea allergy dermatitis. The drug is stored in the body fat and released into the bloodstream over the course of a month. Flea eggs laid prior to treating the pet may take several months to hatch; Program will not be effective until these fleas start to lay eggs. Therefore it may take several months to see the product's effectiveness. If quicker results are needed, use a product which will kill adult fleas; these will provide quicker relief for the pet. Cats require a higher dose per pound than dogs. After the cat injectable form is administered, 2-3 weeks are needed to reach therapeutic levels in the blood. The injectable form for cats is effective for 6 months.

Febantel is a anthelminthic agent used for the treatment of parasitic worms in animals.

Fenbendazole (FBZ) is a broad-spectrum benzimidazole antiparasitic drug currently approved for use in numerous animal species, including rodents. Although nematodes, and in particular pinworms, are the main endoparasites of concern in laboratory rodents, FBZ also is indicated for use in other animal species against a wide spectrum of nematodes, tapeworms, flukes, and protozoa (Giardia duodenalis, Encephalitozoon intestinalis). The molecular mode of fenbendazole action consists in
binding of beta-tubulin monomer prior to dimerisation with alfa-tubulin which blocks subsequent microtubule formation. These microtubules are important organelles involved in the motility, the division and the secretion processes of cells in all living organisms. In the worms the blocking of microtubules perturbs the uptake of glucose, which eventually empties the glycogen reserves. This blocks the whole energy management mechanism of the worms that are paralyzed and die or are expelled. FBZ have a greater binding to nematode as compared to mammalian tubulin at 37°C. The oral LD50 of p-OH fenbendazole was >10 000 mg/kg b.w. in mice and rats.

Ivermectin is a broad-spectrum anti-parasite medication. It was first marketed under the name Stromectol® and used against worms (except tapeworms), but, in 2012, it was approved for the topical treatment of head lice infestations in patients 6 months of age and older, and marketed under the name Sklice™ as well. Ivermectin is mainly used in humans in the treatment of onchocerciasis but is also effective against other worm infestations (such as strongyloidiasis, ascariasis, trichuriasis, and enterobiasis). Ivermectin binds selectively and with high affinity to glutamate-gated chloride ion channels in invertebrate muscle and nerve cells of the microfilaria. This binding causes an increase in the permeability of the cell membrane to chloride ions and results in hyperpolarization of the cell, leading to paralysis and death of the parasite. Ivermectin also is believed to act as an agonist of the neurotransmitter gamma-aminobutyric acid (GABA), thereby disrupting GABA-mediated central nervous system (CNS) neurosynaptic transmission. Ivermectin may also impair the normal intrauterine development of O. volvulus microfilariae and may inhibit their release from the uteri of gravid female worms. It is sold under brand names Heartgard, Sklice and Stromectol in the United States, Ivomec worldwide by Merial Animal Health, Mectizan in Canada by Merck, Iver-DT in Nepal by Alive Pharmaceutical and Ivexterm in Mexico by Valeant Pharmaceuticals International. In Southeast Asian countries, it is marketed by Delta Pharma Ltd. under the trade name Scabo 6.

Moxidectin is a semi-synthetic methoxime derivative of LL F-2924α, commonly referred as F-alpha or nemadectin F-alpha is a product of fermentation of Streptomyces cyaneogriseus subsp. noncyanogenus, a bacterial organism isolated in 1983 from a sample of sand from Victoria, Australia. Moxidectin is a potent, broad-spectrum endectocide with activity against a wide range of nematodes, insects and acari. The compound acts by binding to ligand-gated chloride channels, more specifically the subtypes that are gamma-aminobutyric (GABA) mediated and glutamate-gated. The consequence of Moxidectin binding and activation is an increased permeability, leading to an influx of chloride ions and flaccid paralysis of the parasite leading to death. The macrocyclic lactones probably act by binding to and opening glutamate-gated chloride channels found only in neurons and myocytes of invertebrates. Because moxidectin is very lipophilic, it becomes highly concentrated in the serum. When the concentration of moxidectin in the serum is high, moxidectin is able to cross the blood-brain barrier. Once it is in the central nervous system, a macrocyclic lactone stimulates the synaptic secretion of the inhibitory neurotransmitter, GABA. By binding at the receptor site, GABA causes influx of chloride ions into neurons, causing the neurons to become hyperpolarised, which in turn, causes diminution in neuronal activity, resulting in sedation and relaxation of the skeletal muscles. Signs displayed by foals with moxidectin toxicity included dyspnoea, depression, ataxia, weakness, coma and seizures. In a Phase 3 study compared the efficacy, safety and tolerability of moxidectin and ivermectin in subjects infected with Onchocerca volvulus, which is the parasite that causes river blindness.

Pyrantel is an anthelmintic, which acts as an agonist of nicotinic receptors (AChRs) of nematodes and exerts its therapeutic effects by depolarizing their muscle membranes. It is used to treat a number of parasitic worm infections. This includes ascariasis, hookworm infections, enterobiasis (pinworm infection), trichostrongyliasis and trichinellosis. Common adverse reactions include diarrhea, nausea, vomiting, dizziness, headache and somnolence.