Theophylline for Dogs and Cats: Uses and Side Effects
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Theophylline is a prescription medication that helps open the airways, making it easier for dogs and cats with asthma or other airway diseases to breathe.
Although it is FDA-approved for people, veterinarians commonly prescribe it extra-label for pets when appropriate.
Here’s how theophylline works, when it’s prescribed, possible side effects, dosing guidance, and important safety information.
Key Takeaways
- Theophylline helps widen the airways to improve breathing in dogs and cats with certain respiratory diseases.
- It is commonly prescribed for dogs with airway disease and cats with asthma.
- Give theophylline exactly as directed and avoid administering it with high-fat foods unless instructed otherwise.
- Most pets tolerate theophylline well, but gastrointestinal upset, nervousness, and elevated heart rate can occur.
- Contact your veterinarian immediately if you suspect an overdose because it can be life-threatening.
What Is Theophylline?
Theophylline is a prescription medication that helps widen the airways, making it easier for dogs and cats with certain respiratory diseases to breathe.
Theophylline is commonly prescribed for:
- Dogs with tracheal disease, asthma, or other airway disorders
- Cats with asthma
- Horses with asthma (less commonly)
FDA approval: Theophylline is FDA-approved for human use under the brand names Elixophyllin®, Theo-24®, and generic theophylline.
Although it is not FDA-approved as a veterinary medication, veterinarians may legally prescribe it extra-label (off-label) when appropriate.
Compounded theophylline: In some cases, your veterinarian may recommend a compounded formulation of theophylline when:
- Your pet has difficulty taking the commercially available formulation.
- The required dosage strength is not commercially available.
- Your pet is allergic to an ingredient in the FDA-approved medication.
Compounded medications are not FDA-approved. They are prepared by a veterinarian or licensed pharmacist to meet an individual patient's specific needs.
How Theophylline Works
Theophylline belongs to a class of medications called phosphodiesterase enzyme (PDE) inhibitors.
It relaxes the muscles surrounding the airways, allowing them to widen and improve airflow into the lungs. Theophylline may also help the tiny hair-like structures (cilia) lining the airways move mucus more effectively and reduce excess mucus buildup.
How To Give Theophylline
Give theophylline exactly as directed by your veterinarian.
Administration tips:
- Follow the directions on the prescription label or those provided by your veterinarian.
- Theophylline may be given with or without food, although giving it with food may help reduce the chance of digestive upset.
- Do not give theophylline with high-fat foods such as cheese or butter, as they may increase the absorption of certain formulations and raise the risk of side effects.
Missed a Dose?
If you miss a dose of theophylline, give it as soon as you remember. However, if it is almost time for your pet's next scheduled dose, skip the missed dose and resume the normal dosing schedule.
Do not give extra or double doses.
Theophylline Side Effects
Theophylline is generally well tolerated, but side effects can occur in dogs, cats, and horses.
Common side effects in dogs and cats include:
- Vomiting
- Difficulty sleeping
- Diarrhea
- Increased appetite
- Increased thirst and urination
- Difficulty breathing
- Tremors
- Nervousness
- Elevated heart rate
Side effects in horses may include:
- Increased excitability
- Incoordination
- Excessive sweating
Human Side Effects
Theophylline is also prescribed for people, but human and veterinary doses differ. Pets should never receive medication prescribed for humans.
If you accidentally ingest a pet medication, contact your physician immediately or call the National Poison Control Center at 800-222-1222.
Monitoring Your Pet
No specific monitoring is required while your pet is taking theophylline. However, your veterinarian may recommend routine testing based on your pet's health, other medications, or the condition being treated.
When To Call Your Veterinarian
Contact your veterinarian if:
- Your pet develops severe side effects.
- You suspect your pet has received an overdose.
- You have additional questions or concerns about using theophylline.
Theophylline Overdose
A theophylline overdose is a medical emergency and can be life-threatening.
Signs of an overdose may include:
- Elevated heart rate
- Abnormal heart rhythms
- Fever
- Electrolyte imbalances
- Seizures
If you suspect your pet has received an overdose, contact your veterinarian immediately or an animal poison control center. Consultation fees may apply.
- Pet Poison Helpline: (855) 764-7661
- ASPCA Animal Poison Control: (888) 426-4435
How To Store Theophylline
Store theophylline according to the product label to help maintain its safety and effectiveness.
Storage instructions:
- Store theophylline at controlled temperatures between 59 F and 86 F (15 C–30 C).
- Keep the container tightly closed to protect the medication from moisture and light.
- Store compounded formulations according to the instructions provided by the compounding pharmacy.
- Keep out of reach of children and pets.
Theophylline for Dogs and Cats FAQs
Does theophylline stop coughing in dogs and cats?
Theophylline may help reduce coughing in dogs with certain airway diseases and in cats with asthma, but it may not eliminate coughing completely.
What is an alternative for theophylline for dogs and cats?
Aminophylline is a medication that is very similar to theophylline and may be an appropriate alternative in some pets.
Your veterinarian will determine whether aminophylline or another medication is the best option based on your pet's condition. Do not change your pet's medication without consulting your veterinarian.
Can theophylline be given with food?
Yes. Theophylline may be given with or without food, although giving it with food may help reduce digestive upset. Do not give the medication with high-fat foods unless your veterinarian advises otherwise.
How long does theophylline take to work?
The response time depends on your pet's condition and the formulation prescribed. Your veterinarian can advise you on what to expect based on your pet's treatment plan.
Is theophylline a steroid?
No. Theophylline is a phosphodiesterase (PDE) inhibitor that helps relax the muscles surrounding the airways. It is not a corticosteroid.
No vet writer or qualified reviewer has received any compensation from the manufacturer of the medication as part of creating this article. All content contained in this article is sourced from public sources or the manufacturer.
