Selamectin (trade names Revolution and Stronghold manufactured by Zoetis, and Revolt manufactured by Aurora Pharmaceuticals, among others) is a

topical A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes ...

parasiticide and

anthelminthic Anthelmintics or antihelminthics are a group of antiparasitic drugs that expel parasitic worms (helminths) and other internal parasites from the body by either stunning or killing them and without causing significant damage to the host. They may ...

used on

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...

s and

cat The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of ...

s. It treats and prevents infections of heartworms,

flea Flea, the common name for the order Siphonaptera, includes 2,500 species of small flightless insects that live as external parasites of mammals and birds. Fleas live by ingesting the blood of their hosts. Adult fleas grow to about long, a ...

ear mite Ear mites are mites that live in the ears of animals and humans. The most commonly seen species in veterinary medicine is ''Otodectes cynotis'' (Gk. ''oto''=ear, ''dectes''=biter, ''cynotis''=of the dog). This species, despite its name, is also r ...

sarcoptic mange Mange is a type of skin disease caused by parasitic mites. Because various species of mites also infect plants, birds and reptiles, the term "mange", or colloquially "the mange", suggesting poor condition of the skin and fur due to the infection ...

(scabies), and certain types of

ticks Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". Ticks are external parasites, living by ...

in dogs, and prevents heartworms, fleas, ear mites,

hookworm Hookworms are intestinal, blood-feeding, parasitic roundworms that cause types of infection known as helminthiases. Hookworm infection is found in many parts of the world, and is common in areas with poor access to adequate water, sanitation, an ...

s, and

roundworms The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-parasitic nematodes also known as eelworms. They are a diverse animal phylum inhabiting a broa ...

in cats. It is structurally related to

ivermectin Ivermectin (, '' EYE-vər-MEK-tin'') is an antiparasitic drug. After its discovery in 1975, its first uses were in veterinary medicine to prevent and treat heartworm and acariasis. Approved for human use in 1987, today it is used to treat inf ...

and

milbemycin The milbemycins are a group of macrolides chemically related to the avermectins and were first isolated in 1972 from '' Streptomyces hygroscopicus''. They are used in veterinary medicine as antiparasitic agents against worms, ticks and fleas.

. Selamectin is not approved for human use.

Usage

The drug is applied topically. It is

isopropyl alcohol Isopropyl alcohol (IUPAC name propan-2-ol and also called isopropanol or 2-propanol) is a colorless, flammable organic compound with a pungent alcoholic odor. As an isopropyl group linked to a hydroxyl group ( chemical formula ) it is the s ...

based, packaged according to its varying dosage sizes and applied once monthly. It is not

miscible Miscibility () is the property of two substances to mix in all proportions (that is, to fully dissolve in each other at any concentration), forming a homogeneous mixture (a solution). The term is most often applied to liquids but also applies ...

in water.

Mode of action

Selamectin disables

parasites Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted structurally to this way of lif ...

by activating

glutamate Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can syn ...

-gated

chloride channels Chloride channels are a superfamily of poorly understood ion channels specific for chloride. These channels may conduct many different ions, but are named for chloride because its concentration ''in vivo'' is much higher than other anions. Several ...

muscle Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscl ...

synapses In the nervous system, a synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or to the target effector cell. Synapses are essential to the transmission of nervous impulses from ...

. Selamectin activates the chloride channel without desensitization, allowing chloride ions to enter the

nerve cells A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. ...

and causing neuromuscular

paralysis Paralysis (also known as plegia) is a loss of motor function in one or more muscles. Paralysis can also be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory damage. In the United States, roughly 1 in 50 ...

, impaired

muscular contraction Muscle contraction is the activation of tension-generating sites within muscle cells. In physiology, muscle contraction does not necessarily mean muscle shortening because muscle tension can be produced without changes in muscle length, such as ...

, and eventual death. The substance fights both internal and surface parasitic

infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dise ...

. Absorbed into the body through the skin and

hair follicles The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between h ...

, it travels through the bloodstream, intestines, and

sebaceous glands A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest num ...

; parasites ingest the drug when they feed on the animal's blood or secretions.

Side effects

Selamectin has been found to be safe and effective in a 2003 review. Selamectin has high safety ratings, with less than 1% of pets displaying

side effects In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...

. In cases where side-effects do occur, they most often include passing irritation or hair loss at the application site. Symptoms beyond these (such as drooling, rapid breathing, lack of coordination, vomiting, or diarrhea) could be due to shock as a result of selamectin killing heartworms or other vulnerable parasites present at high levels in the bloodstreams of dogs. This would be a reaction due to undetected or underestimated infections prior to using the medication, rather than an actual allergic reaction to the drug itself.

Similar products

Main rival products for dogs include

(trade names ''Stromectol'', ''Ivermec'' and others) or

milbemycin oxime Milbemycin oxime, sold under the brand name Interceptor among others, is a veterinary medication from the group of milbemycins, used as a broad spectrum antiparasitic. It is active against worms (anthelmintic) and mites (miticide). Mechanism of a ...

(''Interceptor'') for heartworms,

imidacloprid Imidacloprid is a systemic insecticide belonging to a class of chemicals called the neonicotinoids which act on the central nervous system of insects. The chemical works by interfering with the transmission of stimuli in the insect nervous system ...

and

moxidectin Moxidectin is an anthelmintic drug used in animals to prevent or control parasitic worms (helminths), such as heartworm and intestinal worms, in dogs, cats, horses, cattle and sheep. Moxidectin kills some of the most common internal and external ...

(''Advocate''),

fipronil Fipronil is a broad-spectrum insecticide that belongs to the phenylpyrazole chemical family. Fipronil disrupts the insect central nervous system by blocking the ligand-gated ion channel of the GABAA receptor and glutamate-gated chloride (GluCl ...

(''Frontline'') or

lufenuron Lufenuron is the active ingredient in the Veterinary medicine, veterinary flea control medication Program, and one of the two active ingredients in the flea, heartworm, ringworm and anthelmintic medicine milbemycin oxime/lufenuron (Sentinel). Luf ...

(''Program'') for fleas, or the combination milbemycin oxime/lufenuron (''Sentinel'') for both.

References

External links

Pfizer Canada
Antiparasitic agents Macrolides Veterinary drugs Cat medications Dog medications Pfizer brands {{Endectocides