Selarid

Description

Selarid® (selamectin) Topical Parasiticide is presented as a colorless to yellow, ready-to-use solution contained in single-dose applicators, designed for topical (dermal) administration. It is indicated for the treatment of dogs six weeks of age and older and cats eight weeks of age and older. Each applicator is formulated to deliver a minimum dosage of 2.7 mg/lb (6 mg/kg) of body weight of selamectin. The chemical structure of selamectin is defined as (5Z,25S)-25-cyclohexyl-4'-O-de(2,6-dideoxy-3-O-methyl-α-L-arabino-hexopyranosyl)-5-demethoxy-25-de(1-methylpropyl)-22,23-dihydro-5-hydroxyiminoavermectin A1a.

Uses and Indications

This drug is indicated for use in dogs weighing between 20.1 and 40 pounds and at least 6 weeks of age. It is specifically formulated to prevent heartworm disease and to prevent and control flea infestations.

For optimal efficacy, this medication should be administered topically once a month.

Dosage and Administration

The recommended minimum dose of Selarid is 2.7 mg of selamectin per pound (6 mg/kg) of body weight. The entire contents of a single dose applicator should be administered topically. For dogs weighing over 130 pounds, two applicators may be used in combination.

For cats, the dosing is as follows:

• For cats weighing up to 5 lbs: 15 mg (Mauve package), 0.25 mL

• For cats weighing 5.1 – 15 lbs: 45 mg (Blue package), 0.75 mL

• For cats weighing 15.1 - 22 lbs: 60 mg (Taupe package), 1.0 mL

• For cats over 22 lbs, the appropriate combination of applicators should be used.

For dogs, the dosing is as follows:

• For dogs weighing up to 5 lbs: 15 mg (Mauve package), 0.25 mL

• For dogs weighing 5.1 – 10 lbs: 30 mg (Purple package), 0.25 mL

• For dogs weighing 10.1 – 20 lbs: 60 mg (Brown package), 0.5 mL

• For dogs weighing 20.1 – 40 lbs: 120 mg (Red package), 1.0 mL

• For dogs weighing 40.1 – 85 lbs: 240 mg (Teal package), 2.0 mL

• For dogs weighing 85.1 - 130 lbs: 360 mg (Plum package), 3.0 mL

• For dogs over 130 lbs, the appropriate combination of applicators should be used.

Selarid is recommended for use in dogs 6 weeks of age and older and in cats 8 weeks of age and older. Prior to the first use, a veterinarian or veterinary technician should demonstrate or instruct the pet owner on the appropriate technique for applying Selarid topically to both dogs and cats.

To administer the product, part the hair on the back of the animal at the base of the neck in front of the shoulder blades until the skin is visible. Place the tip of the applicator on the skin and squeeze the applicator 3 or 4 times to empty its entire contents directly onto the skin in one spot.

Contraindications

Use of this product is contraindicated in sick, debilitated, or underweight animals.

Application is not recommended on broken skin or when the haircoat is wet. The product should not be massaged into the skin, and contact between the product and fingers should be avoided. This product is not intended for human use and should be kept out of reach of children. In the event of human ingestion, immediate medical attention should be sought.

Warnings and Precautions

Not for human use; this product must be kept out of reach of children. Selarid may cause skin and eye irritation in humans. Reports of adverse reactions, including hives, itching, and skin redness, have been documented. Individuals with a known hypersensitivity to Selarid should exercise caution or consult a healthcare professional prior to use. It is important to note that Selarid contains isopropyl alcohol and the preservative butylated hydroxytoluene (BHT).

To ensure safety, users should wash their hands thoroughly after application and immediately cleanse any product that comes into contact with the skin using soap and water. In the event of eye contact, it is crucial to flush the eyes copiously with water. If contact lenses are being worn, they should be removed after rinsing the eyes, which should continue for 5-10 minutes. Medical attention should be sought promptly if irritation persists. In case of ingestion by a human, immediate contact with a physician is advised.

The product is flammable; therefore, it should be kept away from heat, sparks, open flames, or any other sources of ignition. Additionally, Selarid should not be administered to sick, debilitated, or underweight animals.

For more detailed occupational safety information, the safety data sheet (SDS) is available. To obtain a copy of the SDS, please contact Norbrook at 1-866-591-5777 or visit www.norbrook.com.

Side Effects

Adverse reactions associated with the use of Selarid have been observed in both pre-approval clinical trials and post-approval experiences.

In pre-approval clinical trials involving 691 treated cats, transient localized alopecia, with or without inflammation at or near the site of application, was noted in approximately 1% of subjects. Other adverse signs were reported in ≤0.5% of 1,743 treated cats and dogs, including vomiting, loose stool or diarrhea (with or without blood), anorexia, lethargy, salivation, tachypnea, and muscle tremors.

Post-approval experience has revealed additional adverse events reported for dogs, listed in decreasing order of frequency: lethargy, vomiting, diarrhea, anorexia, generalized pruritus, seizures, application site reactions (which include alopecia, lesions, erythema, pruritus, and inflammation), tremors, ataxia, death, and dermatitis. For cats, the reported adverse events, also in decreasing order of frequency, include application site reactions (such as alopecia, lesions, erythema, pruritus, inflammation, vesicles, blisters, and excoriations), lethargy, anorexia, vomiting, death, generalized pruritus, diarrhea, ataxia, fever, generalized alopecia, tremors, hypersalivation, dermatitis, and seizures.

Warnings indicate that Selarid may be irritating to skin and eyes in humans, with reactions such as hives, itching, and skin redness reported. Individuals with known hypersensitivity to Selarid should use the product with caution or consult a healthcare professional. It is important to note that Selarid is not for human use and should be kept out of reach of children. Additionally, the product is flammable and should be kept away from heat, sparks, open flames, or other sources of ignition.

Drug Interactions

Selarid (selamectin) has demonstrated a favorable safety profile when administered concurrently with various veterinary products, including vaccines, anthelmintics, antiparasitics, antibiotics, steroids, collars, shampoos, and dips.

Prior to the administration of Selarid, it is essential for dogs to undergo testing for existing heartworm infections. In cases where a dog tests positive for adult heartworms, it is imperative that a veterinarian recommends appropriate treatment. For cats aged six months and older, testing for heartworm infections is also advised before initiating treatment with Selarid.

It is important to note that Selarid is not effective against adult Dirofilaria immitis and does not eliminate microfilariae. However, treatment may lead to a reduction in the number of circulating microfilariae.

For animals with an unknown heartworm history that test negative prior to starting Selarid, there is a possibility that they may be harboring pre-patent infections at the time of treatment initiation. Therefore, it is recommended to retest these animals for heartworm status 3 to 4 months after beginning Selarid to confirm their negative status.

Packaging & NDC

The table below lists each NDC Code for Selarid (selamectin) veterinary formulations. Columns show Packaging, Formulation Type, and Active Ingredient Strength.

Pediatric Use

Selarid (selamectin) is indicated for use in dogs six weeks of age and older and cats eight weeks of age and older. The recommended minimum dose is 2.7 mg selamectin per pound (6 mg/kg) of body weight.

In dogs, Selarid is recommended for the prevention and control of flea infestations, prevention of heartworm disease, and treatment and control of ear mite infestations, sarcoptic mange, and tick infestations. For cats, it is indicated for the prevention and control of flea infestations, prevention of heartworm disease, treatment and control of ear mite infestations, and treatment and control of roundworm and intestinal hookworm infections.

Prior to the first use, a veterinarian or veterinary technician should demonstrate or instruct the pet owner on the appropriate technique for applying Selarid topically to dogs and cats. Selarid should not be administered to dogs younger than six weeks of age or cats younger than eight weeks of age.

In safety studies, selamectin solution was applied at 1, 3, 5, and 10 times the recommended dose to six-week-old puppies and kittens, with no adverse reactions observed. Dogs should be tested for existing heartworm infections prior to administration of Selarid. At the discretion of the veterinarian, cats six months of age and older may also be tested for the presence of existing heartworm infections before beginning treatment with Selarid.

Geriatric Use

Elderly patients, defined as those aged 65 years and older, should be approached with caution when considering the use of Selarid. It is important to note that Selarid is recommended for use in dogs six weeks of age or older and in cats eight weeks of age and older. However, Selarid should not be administered to sick, debilitated, or underweight animals, which may include some geriatric patients.

Prior to the administration of Selarid, it is advisable for veterinarians to test dogs for existing heartworm infections. For cats aged six months and older, testing may also be considered at the veterinarian's discretion to determine the presence of heartworm infections before initiating treatment with Selarid. It is critical to highlight that Selarid is not effective against adult Dirofilaria immitis and does not facilitate microfilariae clearance.

While hypersensitivity reactions have not been observed in dogs with patent heartworm infections treated with selamectin solution, caution is warranted. A case involving a malnourished and underweight kitten, estimated to be 5–6 weeks old, resulted in death following treatment with selamectin solution, highlighting the potential risks associated with administering this medication to compromised animals.

In safety studies, selamectin solution was administered at various dosages (1, 3, 5, and 10 times the recommended dose) to six-week-old puppies without any adverse reactions noted. Additionally, the safety of oral administration of selamectin was evaluated in cases of accidental ingestion, with no adverse reactions observed in 5- to 8-month-old beagles. A pre-clinical study involving ivermectin-sensitive collies indicated that while no adverse reactions were generally observed, one collie did experience ataxia after receiving a higher dose of 5 mg/kg orally.

Selarid has been tested for safety in over 100 different pure and mixed breeds of healthy dogs and more than 15 different pure and mixed breeds of healthy cats, including pregnant and lactating females, breeding males and females, puppies six weeks of age and older, and kittens eight weeks of age and older. Given these findings, careful consideration and monitoring are recommended when administering Selarid to geriatric patients, particularly those with underlying health concerns.

Pregnancy

Selamectin solution has been evaluated for safety in over 100 different pure and mixed breeds of healthy dogs and more than 15 different pure and mixed breeds of healthy cats, including pregnant and lactating females. While the use of Selarid in pregnant animals has not been associated with specific fetal risks in these studies, caution is advised when administering this treatment to pregnant patients.

Selarid is not effective against adult Dirofilaria immitis, and although treatment may lead to a decrease in the number of circulating microfilariae, it does not facilitate microfilariae clearance. Therefore, it is recommended that dogs be tested for existing heartworm infections prior to the administration of Selarid. Additionally, at the discretion of the veterinarian, cats aged 6 months or older may be tested for heartworm infections before initiating treatment.

It is important to note that Selarid should not be used in sick, debilitated, or underweight animals. A case was reported involving a kitten, estimated to be 5–6 weeks old and weighing 0.3 kg, which died 8.5 hours after receiving a single treatment of selamectin solution at the recommended dosage. The kitten exhibited clinical signs including muscle spasms, salivation, and neurological symptoms. This kitten was a stray with an unknown history and was malnourished and underweight, highlighting the need for careful consideration of the health status of animals prior to treatment.

Lactation

Selamectin solution has been tested for safety in over 100 different pure and mixed breeds of healthy dogs and over 15 different pure and mixed breeds of healthy cats, including pregnant and lactating females. The data suggest that Selamectin is safe for use in lactating mothers.

Additionally, dogs infected with adult heartworms can safely be administered Selarid, and cats infected with adult heartworms can also receive Selarid to prevent further infections. There is no specific information available regarding the excretion of Selamectin in breast milk or its effects on breastfed infants. Therefore, healthcare professionals should consider the benefits and risks when recommending this treatment to lactating mothers.

Renal Impairment

Patients with renal impairment have not been specifically addressed in the drug insert regarding dosage adjustments, special monitoring, or safety considerations. Therefore, healthcare professionals should exercise caution when prescribing this medication to patients with reduced kidney function, as the absence of detailed guidance necessitates careful clinical judgment. Regular monitoring of renal function may be advisable in these patients to ensure safety and efficacy.

Hepatic Impairment

Patients with hepatic impairment have not been specifically studied in relation to this medication. Consequently, there are no established dosage adjustments, special monitoring requirements, or precautions outlined for individuals with compromised liver function. It is recommended that healthcare providers exercise caution when prescribing this medication to patients with hepatic impairment, given the lack of data on its safety and efficacy in this population. Regular monitoring of liver function may be prudent in these cases, although specific parameters are not defined in the prescribing information.

Overdosage

In the event of overdosage, it is imperative that a physician is contacted immediately following ingestion by a human. Prompt medical attention is crucial to ensure appropriate management and intervention.

Healthcare professionals should be vigilant for potential symptoms associated with overdosage, which may vary depending on the specific substance involved. The clinical presentation can include a range of effects, necessitating a thorough assessment of the patient.

Management procedures should be initiated as soon as possible. This may involve supportive care, monitoring of vital signs, and symptomatic treatment as required. The healthcare provider may also consider the use of specific antidotes or interventions based on the substance involved and the severity of the symptoms.

It is essential for healthcare professionals to remain informed about the appropriate protocols for managing overdosage cases, including the potential need for referral to specialized toxicology services if warranted.

Nonclinical Toxicology

Selamectin solution has been evaluated for its safety in a variety of animal populations, including over 100 different pure and mixed breeds of healthy dogs and more than 15 different pure and mixed breeds of healthy cats. This includes assessments involving pregnant and lactating females, breeding males and females, puppies six weeks of age and older, kittens eight weeks of age and older, and avermectin-sensitive collies. No specific teratogenic effects have been identified in the studies conducted.

In a notable incident, a kitten estimated to be 5–6 weeks old (0.3 kg) died 8 ½ hours after receiving a single treatment of selamectin solution at the recommended dosage. The kitten exhibited clinical signs such as muscle spasms, salivation, and neurological symptoms. It is important to note that this kitten was a stray with an unknown history and was malnourished and underweight at the time of treatment.

In safety studies, selamectin solution was administered at 1, 3, 5, and 10 times the recommended dose to six-week-old puppies, with no adverse reactions observed. Additionally, the safety of selamectin solution was assessed in cases of accidental oral ingestion. Oral administration of selamectin solution at the recommended topical dose in 5- to 8-month-old beagles did not result in any adverse reactions. In a pre-clinical study involving ivermectin-sensitive collies, oral administration of 2.5, 10, and 15 mg/kg did not cause adverse reactions; however, one collie became ataxic for several hours after receiving 5 mg/kg orally, but did not exhibit any further adverse reactions after subsequent doses of 10 and 15 mg/kg.

A topical safety study conducted with avermectin-sensitive collies at 1, 3, and 5 times the recommended dose of selamectin solution noted salivation in all treatment groups, including the vehicle control. Selamectin solution was also administered at 3 times the recommended dose to heartworm-infected dogs, with no adverse effects reported. In safety studies involving six-week-old kittens, selamectin solution was applied at 1, 3, 5, and 10 times the recommended dose, and no adverse reactions were observed.

The safety of selamectin solution was further evaluated in cases of accidental oral ingestion in cats, where administration of the recommended topical dose resulted in salivation and intermittent vomiting. In heartworm-infected cats, selamectin solution was applied at 4 times the recommended dose without any adverse reactions.

In well-controlled clinical studies, selamectin solution has been used safely in conjunction with other commonly used veterinary products, including vaccines, anthelmintics, antiparasitics, antibiotics, steroids, collars, shampoos, and dips.

Postmarketing Experience

Adverse events reported in the postmarketing experience for dogs include lethargy, vomiting, diarrhea, anorexia, generalized pruritus, seizures, application site reactions (such as alopecia, lesions, erythema, pruritus, and inflammation), tremors, ataxia, death, and dermatitis, listed in decreasing order of reporting frequency.

For cats, the reported adverse events, also in decreasing order of frequency, include application site reactions (including alopecia, lesions, erythema, pruritus, inflammation, vesicles, blisters, and excoriations), lethargy, anorexia, vomiting, death, generalized pruritus, diarrhea, ataxia, fever, generalized alopecia, tremors, hypersalivation, dermatitis, and seizures.

Transient localized alopecia with or without inflammation at or near the site of application was observed in approximately 1% of 691 treated cats. Other signs reported in ≤0.5% of 1743 treated cats and dogs included vomiting, loose stool or diarrhea with or without blood, anorexia, lethargy, salivation, tachypnea, and muscle tremors.

Severe application site reactions, such as blisters, scabbing, and infection, have been reported in cats. Additionally, cases of death have been reported in both dogs and cats.

Patient Counseling

Healthcare providers should inform patients that Selarid (selamectin) is a topical parasiticide intended for use in dogs six weeks of age and older and cats eight weeks of age and older. It is effective in killing adult fleas, preventing flea eggs from hatching, preventing heartworm disease, and protecting against other parasites.

Patients should be advised that Selarid is contraindicated in sick, debilitated, or underweight animals. Prior to administering Selarid, dogs should be tested for heartworm disease. If a dog tests positive for adult heartworms, the veterinarian can recommend appropriate treatment. It is important to note that dogs infected with adult heartworms can still safely receive Selarid. For cats older than six months, the veterinarian may decide to test for heartworm disease before prescribing Selarid, although cats infected with adult heartworms can also be treated with Selarid to prevent further infections.

In the event that a monthly dose of Selarid is forgotten, patients should be instructed to apply it immediately, resume the monthly schedule, and notify their veterinarian. If more than the prescribed amount of Selarid is administered, patients should contact their veterinarian for guidance.

Patients should be shown how to properly use the applicator. They should remove the applicator from the outer pouch using scissors or by folding along the diagonal line to expose the nick, then tearing back at the nick. The applicator should be held upright, and the narrow part should be tapped to ensure the contents remain within the main body. The tip should be twisted or snapped back before parting the hair on the back of the animal at the base of the neck, in front of the shoulder blades, until the skin is visible. The tip of the applicator should be applied directly to the skin, and the applicator should be squeezed firmly 3–4 times in one spot until empty, ensuring that the applicator remains compressed on the final squeeze to avoid drawing liquid back in. Patients should be cautioned to avoid contact between Selarid and their fingers.

After application, patients should not massage Selarid into the skin, and it should not be applied when the haircoat is wet or to broken skin, as Selarid contains alcohol. They may observe stiff hair, clumping, discoloration, or a slight powdery residue at the application site; these effects are typically temporary and do not affect the product's safety or effectiveness.

Patients can be reassured that bathing or shampooing the dog two or more hours after treatment will not reduce the effectiveness of Selarid against fleas or heartworm, and bathing or shampooing the cat 24 hours after treatment will also not diminish its effectiveness. However, they should avoid contact with the application site when wet and may hold or play with their pet once the area is dry.

It is crucial to emphasize that Selarid is not for use in humans and should be kept out of reach of children. Patients should be made aware that Selarid may cause skin and eye irritation in humans, with reported reactions including hives, itching, and skin redness. Individuals with known hypersensitivity to Selarid should use the product with caution or consult a healthcare professional. Patients should wash their hands after use and immediately wash off any product that comes into contact with their skin using soap and water. In the case of human ingestion, they should contact a doctor immediately.

Storage and Handling

The product is supplied in various package configurations, with specific NDC numbers available for identification. It is essential to store the product in a controlled environment, maintaining a temperature below 86°F (30°C) to ensure its stability and efficacy. Proper container requirements should be adhered to, and any special handling needs must be followed to preserve the integrity of the product.

Additional Clinical Information

Selarid is administered topically, with the entire contents of a single dose applicator used for dogs weighing up to 130 pounds, and two applicators for those over 130 pounds. For effective flea control, it should be applied monthly throughout the flea season, starting one month prior to flea activity. Monthly administration is also required for heartworm prevention and tick control in dogs. For ear mite infestations and sarcoptic mange in dogs, a single topical dose is sufficient. In cats, Selarid is applied once as a single topical dose for the treatment and control of intestinal hookworm and roundworm infections.

Clinicians should counsel patients on proper application techniques, including washing hands after use and avoiding contact with the skin. In the event of eye contact, thorough rinsing is advised, and ingestion by humans necessitates immediate medical attention. Temporary effects such as stiff hair, clumping, discoloration, or a powdery residue may occur at the treatment site but do not compromise the product's safety or efficacy. Postmarketing experience has revealed adverse events in dogs, including lethargy, vomiting, and application site reactions, while cats have reported similar reactions along with additional symptoms such as hypersalivation and seizures.

Drug Information (PDF)

This document includes the full labeling information for Selarid, as submitted by Norbrook Laboratories Limited for veterinary use. It may include dosage by species, withdrawal periods, and administration instructions.

View veterinary label (PDF)