Selamectin

Uses and Indications

This drug is indicated for the prevention and control of flea infestations (Ctenocephalides felis) and the prevention of heartworm disease caused by Dirofilaria immitis in dogs and cats. It is also indicated for the treatment and control of ear mite infestations (Otodectes cynotis), sarcoptic mange (Sarcoptes scabiei), and tick infestations due to Dermacentor variabilis in dogs. In cats, it is indicated for the treatment and control of roundworm (Toxocara cati) and intestinal hookworm (Ancylostoma tubaeforme) infections.

Species and Age Limitations:

• This drug is indicated for use in dogs six weeks of age or older and cats eight weeks of age or older.

Usage Instructions:

• The drug should be administered topically once a month to ensure effective prevention and control of the indicated conditions.

Dosage and Administration

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

For Cats:

• Up to 5 lbs: 15 mg (Mauve package), 0.25 mL

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

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

• For cats over 22 lbs, use the appropriate combination of tubes or applicators.

For Dogs:

• Up to 5 lbs: 15 mg (Mauve package), 0.25 mL

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

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

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

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

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

• For dogs over 130 lbs, use the appropriate combination of tubes or applicators.

Selamectin is recommended for use in dogs 6 weeks of age and older and in cats 8 weeks of age and older. A veterinarian or veterinary technician should demonstrate or instruct the pet owner on the appropriate technique for applying the product topically to dogs and cats prior to first use.

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 tube or applicator on the skin and squeeze it 3 or 4 times to empty its entire contents directly onto the skin in one spot. It is important not to massage the product into the skin.

For the prevention and control of flea infestations, selamectin should be administered at monthly intervals throughout the flea season, starting one month before fleas become active. For the prevention of heartworm disease, it must also be administered on a monthly basis.

For the treatment of ear mite infestations, sarcoptic mange in dogs, and for the control of tick infestations in dogs, selamectin should be administered once as a single topical dose, with a second monthly dose possibly required in some cases. For the treatment and control of intestinal hookworm and roundworm infections, a single topical dose is sufficient.

Contraindications

Do not use Selaspot in sick, debilitated, or underweight animals. The product should not be applied to broken skin or when the haircoat is wet. It is contraindicated to massage the product into the skin or allow contact between the product and fingers. Selaspot may cause skin and eye irritation in humans; therefore, individuals with known hypersensitivity to Selaspot should use the product with caution or consult a healthcare professional. In the event of human ingestion, immediate medical attention is required.

Warnings and Precautions

Not for human use. Keep out of reach of children. In humans, these products may be irritating to skin and eyes. Reactions such as hives, itching, and skin redness have been reported. Individuals with known hypersensitivity to any of these products should use them with caution or consult a health care professional. Each product contains isopropyl alcohol and the preservative butylated hydroxytoluene (BHT).

It is essential to wash hands after use and to wash off any product that comes into contact with the skin immediately with soap and water. If contact with eyes occurs, flush eyes copiously with water; if wearing contact lenses, rinse the eyes first, then remove contact lenses and continue to rinse for 5-10 minutes. Seek medical attention if irritation persists. In case of ingestion by a human, contact a physician immediately.

These products are flammable; keep away from heat, sparks, open flames, or other sources of ignition.

Animal Safety Warnings: Do not use in sick, debilitated, or underweight animals.

For more detailed occupational safety information, refer to the safety data sheet (SDS). To obtain an SDS, contact Norbrook at 1-866-591-5777 or visit www.norbrook.com.

Side Effects

Transient localized alopecia with or without inflammation at or near the site of application was observed in approximately 1% of 691 treated cats during pre-approval clinical trials. Other signs observed 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.

Post-Approval Experience (2021)

Dogs

The following adverse events were reported in dogs, listed in decreasing order of frequency:

• Lethargy

• Vomiting

• Diarrhea

• Anorexia

• Generalized pruritus

• Seizures

• Application site reactions (including alopecia, lesions, erythema, pruritus, and inflammation)

• Tremors

• Ataxia

• Death

• Dermatitis

Cats

The following adverse events were reported in cats, listed in decreasing order of frequency:

• 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

• Seizures

Warnings

In humans, the product may be irritating to skin and eyes, with reactions such as hives, itching, and skin redness reported. Individuals with known hypersensitivity to the product should use it with caution or consult a healthcare professional. The product is not for human use and should be kept out of reach of children.

Additional Notes

The product is flammable; it should be kept away from heat, sparks, open flames, or other sources of ignition.

Drug Interactions

There are no documented drug interactions associated with Selaspot. Additionally, there is no information available regarding interactions with laboratory tests. Therefore, healthcare professionals can consider Selaspot as having a low potential for drug-related complications in terms of interactions.

Pediatric Use

SelaSpot (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 safety studies, selamectin was administered to six-week-old puppies and kittens at 1, 3, 5, and 10 times the recommended dose, with no adverse reactions observed. However, a case was reported involving a kitten estimated to be 5–6 weeks old (0.3 kg) that died 8 1⁄2 hours after receiving a single treatment of selamectin at the recommended dosage. This kitten exhibited clinical signs including muscle spasms, salivation, and neurological symptoms. It is important to note that the kitten was a stray with an unknown history and was malnourished and underweight.

SelaSpot is not to be administered to dogs younger than 6 weeks of age or cats younger than 8 weeks of age.

Geriatric Use

Elderly patients, particularly those aged 65 years and older, may require careful consideration when prescribing SelaSpot. It is recommended that geriatric patients be tested for heartworm disease prior to administration of the solution. For dogs, a positive test for adult heartworms necessitates consultation with a veterinarian for appropriate treatment options. In cats, those older than six months should also be evaluated for heartworm disease before receiving SelaSpot. While SelaSpot can be safely administered to both dogs and cats infected with adult heartworms to prevent further infections, caution is advised in sick, debilitated, or underweight animals. Regular monitoring and appropriate dose modifications may be necessary to ensure safety and efficacy in this population.

Pregnancy

Selamectin has been evaluated for safety in pregnant patients, with studies indicating it is safe for use 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. There is no evidence suggesting adverse fetal outcomes associated with the administration of Selamectin in these populations.

However, caution is advised when administering Selamectin to kittens, particularly those with unknown health histories. A case was reported where a 5–6 week old kitten died 8.5 hours after receiving a single treatment of selamectin at the recommended dosage. The kitten exhibited clinical signs such as muscle spasms, salivation, and neurological symptoms prior to its death. It is important to note that this kitten was a stray, malnourished, and underweight, which may have contributed to its adverse reaction.

Healthcare professionals are encouraged to consider the overall health and nutritional status of pregnant patients and their offspring when prescribing Selamectin, and to monitor for any unusual reactions following treatment.

Lactation

Selamectin has been tested for safety in lactating females, including both dogs and cats. The data indicates that Selamectin can be administered to lactating mothers without adverse effects. While specific information regarding excretion in breast milk is not provided, the safety profile in lactating animals suggests a low risk for breastfed infants.

Healthcare professionals should consider the overall health of the lactating mother and the potential for any underlying conditions when recommending Selamectin. As always, monitoring for any unusual reactions in both the mother and the offspring is advisable.

Renal Impairment

Patients with renal impairment may not have specific dosage adjustments, monitoring requirements, or safety considerations outlined in the product inserts for the following medications: Selarid, Selaspot, Revolution, Revolt, and Senergy. The absence of information regarding renal function suggests that no modifications to dosing or special precautions are necessary for this patient population. However, healthcare providers should remain vigilant and consider individual patient circumstances when prescribing these medications, as the lack of specific guidance does not preclude the potential for altered pharmacokinetics in patients with reduced kidney function.

Hepatic Impairment

Patients with hepatic impairment do not have specific dosage adjustments, special monitoring requirements, or precautions outlined in the drug inserts for Selarid, Selaspot, Revolution, Revolt, and Senergy. The available information does not provide guidance on the use of these medications in individuals with liver problems. Therefore, healthcare professionals should exercise caution and consider individual patient factors when prescribing these treatments to patients with hepatic impairment.

Overdosage

In the event of ingestion by a human, it is imperative to contact a physician immediately for guidance and management. Symptoms of overdose may not be explicitly detailed in the available data; however, prompt medical attention is essential.

Monitoring of the patient should be initiated, and supportive care may be required based on the clinical presentation. As no specific overdosage information is provided for some formulations, the healthcare provider should assess the situation and determine the appropriate interventions based on the patient's condition and any symptoms that may arise.

It is crucial to follow established medical protocols for overdose management, ensuring that the patient receives timely and effective care.

Nonclinical Toxicology

Teratogenic Effects

No teratogenic effects were observed in studies involving selamectin. There is no information available regarding teratogenic effects for selarid.

Non-Teratogenic Effects

Selamectin 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, breeding males and females, puppies six weeks of age and older, and kittens eight weeks of age and older. A case was reported where a malnourished stray kitten, estimated to be 5–6 weeks old, died 8.5 hours after receiving a single treatment of selamectin at the recommended dosage, exhibiting clinical signs such as muscle spasms, salivation, and neurological symptoms.

Animal Toxicology

In safety studies, selamectin was administered at 1, 3, 5, and 10 times the recommended dose to six-week-old puppies, with no adverse reactions observed. The safety of selamectin was also evaluated in cases of accidental oral ingestion. Oral administration of selamectin 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 showed no further adverse effects after subsequent doses of 10 and 15 mg/kg.

In a topical safety study with avermectin-sensitive collies, salivation was noted in all treatment groups, including the vehicle control. Selamectin was also administered at 3 times the recommended dose to heartworm-infected dogs, with no adverse effects reported. Additionally, safety studies involving six-week-old kittens showed no adverse reactions when selamectin was applied at 1, 3, 5, and 10 times the recommended dose. In cases of accidental oral ingestion in cats, salivation and intermittent vomiting were observed after administering the recommended topical dose. Selamectin was also applied at 4 times the recommended dose to heartworm-infected cats, with no adverse reactions noted.

For selarid, it is advised not to use the product in sick, debilitated, or underweight animals, although no specific nonclinical toxicology data is provided.

Storage and Handling

Selarid, Selaspot, Revolution, and Revolt are supplied as solutions. It is essential to store these products under specific temperature conditions to maintain their efficacy.

• Selarid: Store below 86°F (30°C).

• Selaspot: Store below 25°C (77°F).

• Revolution: Store below 30°C (86°F).

• Revolt: Store below 30°C (86°F).

• Senergy: Store below 25°C (77°F).

• Selamectin: No specific storage instructions or handling details are provided.

Adhering to these storage conditions is crucial for ensuring the stability and effectiveness of the solutions.