Selamectin, sold under the brand name Revolution, 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 used on

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the gray wolf. Also called the domestic dog, it was selectively bred from a population of wolves during the Late Pleistocene by hunter-gatherers. ...

s and

cat The cat (''Felis catus''), also referred to as the domestic cat or house cat, is a small domesticated carnivorous mammal. It is the only domesticated species of the family Felidae. Advances in archaeology and genetics have shown that the ...

s. It treats and prevents infections of

heartworms ''Dirofilaria immitis'', also known as heartworm or dog heartworm, is a Parasitism, parasitic Nematode, roundworm that is a type of Filarioidea, filarial worm, a small thread-like worm, and which causes dirofilariasis. It is spread from host (bi ...

flea Flea, the common name for the order (biology), order Siphonaptera, includes 2,500 species of small flightless insects that live as external parasites of mammals and birds. Fleas live by hematophagy, ingesting the blood of their hosts. Adult f ...

ear mite Ear mites are mites that live in the ears of animals. 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 responsibl ...

s, sarcoptic mange (scabies), and certain types of

ticks Ticks are parasitic arachnids of the order Ixodida. They are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, and species, but can become larger when engorged. Ticks a ...

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

hookworm Hookworms are Gastrointestinal tract, intestinal, Hematophagy, blood-feeding, parasitic Nematode, 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 ...

s, and

roundworms The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (hel ...

in cats. It is structurally related to

ivermectin Ivermectin 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, it is used to treat infestations including head lice ...

and milbemycin. Selamectin is not approved for human use.

Veterinary uses

Selamectin is applied topically. 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). Such substances are said to be miscible (etymologically ...

in water.

Mode of action

Selamectin disables

parasites Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The en ...

by activating

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

-gated chloride channels at

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

synapses In the nervous system, a synapse is a structure that allows a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or a target effector cell. Synapses can be classified as either chemical or electrical, depending o ...

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

nerve cells A neuron (American English), neurone (British English), or nerve cell, is an excitable cell that fires electric signals called action potentials across a neural network in the nervous system. They are located in the nervous system and help to ...

and causing neuromuscular

paralysis Paralysis (: paralyses; also known as plegia) is a loss of Motor skill, motor function in one or more Skeletal muscle, muscles. Paralysis can also be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory d ...

, 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 tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmis ...

. 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 ho ...

, it travels through the bloodstream, intestines, and

sebaceous glands A sebaceous gland or oil 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 t ...

; 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 of the use of a medicinal drug or other treatment, usually adverse but sometimes beneficial, that is unintended. Herbal and traditional medicines also have side effects. A drug or procedure usually used ...

. 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.

Society and culture

Brand names

Selamectin is sold under various brand names including Selehold, manufactured by KRKA, Selarid manufactured by Norbrook Laboratories Limited, Revolution and Stronghold manufactured by Zoetis, Revolt manufactured by Aurora Pharmaceuticals, and Senergy manufactured by Virbac.

Similar products

Main rival products for dogs include

(trade names Stromectol, Ivermec and others) or milbemycin oxime (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, sheep and wombats. Moxidectin kills some of the most common internal ...

(Advocate),

fipronil Fipronil is a broad-spectrum insecticide that belongs to the phenylpyrazole insecticide class. Fipronil disrupts the insect central nervous system by blocking the ligand-gated ion channel of the GABAA receptor ( IRAC group 2B) and glutamate-g ...

(Frontline) or

lufenuron Lufenuron is the active ingredient in the veterinary flea control medication program, and one of the two active ingredients in the flea, heartworm, and anthelmintic medicine milbemycin oxime/lufenuron (Sentinel). Lufenuron is stored in the anim ...

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

References

{{Authority control Antiparasitic agents Macrolides Cat medications Dog medications Drugs developed by Pfizer Cyclohexyl compounds