The content of Cn Breaking News drugs has been written and reviewed by vets to answer your most common questions about the effects of drugs, their side effects, and the types of animals they’re prescribed for. This content should not replace your vet’s advice.
What is chlorpheniramine?
Chlorpheniramine is an antihistamine commonly used for dogs and cats with allergies or itching associated with certain types of skin hypersensitivity. It hasn’t been used with much success in dogs, but is more commonly used on cats, ferrets, and birds. In horses, it is used for hypersensitivity to insect bites. Chlorpheniramine is an over-the-counter antihistamine that is best used to prevent allergies.
Chlorpheniramine has also been used in dogs to prevent the release of histamine associated with mast cell tumors during surgery to remove these types of tumors.
Chlorpheniramine is approved by the FDA for human use under the brand names Aller-Chlor ® and Chlor-Trimeton ®. It is not currently approved by the FDA as a veterinary drug. However, it is readily used in the veterinary sector and, under certain circumstances, veterinarians may legally prescribe or recommend certain medicinal products for human use in animals. This is referred to as extra-labelled or off-label use because this use is not described on the drug label.
In some circumstances, your vet may prescribe a compound formulation of chlorpheniramine. Combined medications are prescribed when there is a specific reason why your pet’s health can’t be treated by an FDA-approved medication, such as if your pet has trouble taking pills in capsule form, the dosage strength isn’t commercially available, or the pet is allergic to any ingredient of the FDA-approved drug. Compound drugs are not approved by the FDA. They are created individually by either a vet or a licensed pharmacist to best meet the patient’s particular needs. You can learn more about compound medications here.
It’s important to note that some chlorpheniramine products come in combination with other medications that are toxic to dogs and cats. Therefore, talk to your vet about which product is right for your pet, as when giving it to dogs or cats, you should use products that contain only chlorpheniramine.
How does chlorpheniramine work
Chlorpheniramine belongs to a class of medications called antihistamines. The body’s immune system releases a naturally occurring chemical called histamine to protect the body by reacting to triggers (allergens) such as insect bites, parasites, or pollen.
Histamine removes the allergen and can cause inflammation or pain, increase heart rate, dilate blood vessels while increasing stomach acid production. Pets can produce other chemicals similar to histamine, which also contribute to allergic reactions, which is why antihistamines such as chlorpheniramine tend to be less effective in pets than in humans.
Follow the instructions on the medicine label or your vet’s instructions. Chlorpheniramine is typically given orally 2 to 3 times daily. The bitter taste of chlorpheniramine may make it difficult to give to pets. Some may become drowsy while taking this medication, but the calming effects usually subside over time.
Did you miss a dose?
Talk to your vet about what to do if you forget to give a dose of chlorpheniramine. In general, they will advise you to give it when you remember, or when it is almost time for your next dose, to skip the missed dose and resume your normal dosing schedule. In most cases, you should not give extra or double doses.
chlorpheniramine Possible side effects
The most common side effect of this medication is drowsiness. Other side effects include:
loss of appetite
Excitement (especially with cats)
drooling (especially in cats — due to the bitter taste)
Side effects in humans
Although it is a prescription drug for humans, humans may experience different dosages and side effects. If you accidentally take a pet medication, call your doctor or the national poison control center hotline at 800-222-1222.
This medication does not require specific monitoring, but your vet may recommend routine testing depending on your pets’ unique needs, other medications they may be taking, or the problem that originally caused your pet to receive this medication.
Call your vet if:
Serious side effects occur (see above)
Your pet’s condition doesn’t get worse or improve with treatment
You see or suspect an overdose
You have further questions or concerns about using chlorpheniramine.
Chlorpheniramine Overdose Information
While chlorpheniramine is generally safe to use in pets, overdoses may occur. Symptoms of an overdose include:
Verlust der Coordination
Gefährlich niedrige Atmung oder Herzfrequenz
Stark Trockener Mund
If you suspect an overdose, contact your vet immediately, seek emergency veterinary care, or contact a poison control center for animals. Consulting fees are often charged.
Pet poison control number (855) 764-7661
ASPCA poison control in animals (888) 426-4435
Chlorpheniramine should be stored according to the drug label and at 77 F. Short-term exposure to temperatures of 59-86 F is acceptable. Keep the container tightly closed to protect this medication from moisture and light.
Compound medications should be stored according to the compounding pharmacy label.
Keep out of reach of children and pets.
Frequently asked questions about chlorpheniramine
Does chlorpheniramine make pets drowsy?
One of the known side effects of chlorpheniramine is that it may make your pet drowsy. Mild drowsiness usually decreases the longer your pet takes this medication. If your pet is excessively drowsy, talk to your vet about changing the dose of this medication or using an alternative product. If your pet can’t be woken from sleep, it could be an emergency. Contact a vet immediately or seek emergency veterinary care.
Eichenseer M, Johansen C, Müller RS. Efficacy of dimetindene and hydroxyzine/chlorpheniramine in atopic dogs: a randomized, controlled, double-blind trial Veterinary registry. 2013; 173 (17) :423.
No veterinary author or qualified expert has received any compensation from the manufacturer of the medicinal product as part of the preparation of this article. All content in this article comes from public sources or the manufacturer.
Featured image: istock.com/Michele Pevide