Hydrocodone with Homatropine
What is hydrocodone with homatropine?
Hydrocodone with homatropine is a combination antitussive (cough suppressant) medication used to treat coughing in dogs. It contains an opiate narcotic (hydrocodone) and an anticholinergic (homatropine).
It is used off label (extra label) in veterinary medicine. Many drugs are commonly prescribed for off-label use in veterinary medicine. “Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.
How do I give my pet hydrocodone with homatropine oral?
- Hydrocodone with homatropine comes in liquid suspension and tablet forms.
- All forms are given orally (by mouth).
- Measure liquid medication carefully.
- This medication may be given with food or on an empty stomach.
- If your pet vomits or acts sick after receiving the drug on an empty stomach, try giving the next dose with a small amount of food or a small treat.
- Give this medication to your pet for the entire time prescribed by your veterinarian, even if it appears that your pet is feeling better.
This medication should take effect within 1 to 2 hours.
What if I miss giving my pet the medication?
If you miss a dose, give it as soon as you remember, and then wait the recommended time for the next dose, as prescribed by your veterinarian. Do not give the pet two doses at once.
Are there any potential side effects?
Hydrocodone with homatropine may cause the following side effects:
- Mild sedation or sleepiness
- Constipation
- Reduced appetite, vomiting
- Excitement
The following reactions are rare, but if they occur, contact your veterinarian immediately:
- An allergic reaction, such as irregular breathing, rash, fever, puffiness and swelling around the face
- Low breathing rate and/or low heart rate
- Urine retention
Drug sensitivities can develop over time with repeated exposure. Your pet may have no reaction after the first few doses, but may develop a sensitivity later. It is important to watch for signs of an allergic reaction over the entire course of treatment.
Other side effects may occur. If you notice anything unusual, contact your veterinarian immediately. This medication is short-acting, meaning that effects will last less than 24 hours, though effects may last longer in pets with kidney or liver disease.
Are there any risk factors for this medication?
DO NOT USE hydrocodone with homatropine oral in:
- Pets that are allergic to any component of the medication and/or allergic to similar medications (e.g., other opiates, atropine-like drugs)
- Pets that have diarrhea caused by a toxic substance
USE WITH CAUTION in:
- Pets whose cause of coughing is unknown
- Pets with severe kidney, thyroid, heart, adrenal, and/or liver disease
- Pets with a head injury
- Pets that are working animals and need to be alert to perform their job
- Pets that are old, weak, frail
Are there any drug interactions I should be aware of?
Certain medications should be USED WITH CAUTION when given with hydrocodone with homatropine, including:
- Antidepressants (e.g., fluoxetine, amitriptyline, mirtazapine, trazodone, selegiline)
- Benzodiazepines (e.g., alprazolam, diazepam)
- Central nervous system (CNS) depressants (e.g., phenobarbital, antihistamines)
- Clopidogrel
- CYP3A inhibitors (e.g., cimetidine, itraconazole)
- Diuretics (e.g., furosemide)
- Opioids and reversal agents (e.g., buprenorphine, naloxone)
- Other anticholinergics (e.g., atropine)
- Prokinetics (e.g., cisapride, metoclopramide)
- Rifampin
- Skeletal muscle relaxants (e.g., dantrolene, methocarbamol)
Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking before starting any new treatment.
Is any monitoring needed with this medication?
- Your veterinarian will let you know when and how they want to reassess your pet to ensure the medication is working and not causing side effects.
- At home, monitor for any side effects such as those noted above. If any occur, stop using the medication and contact your veterinarian.
How do I store hydrocodone with homatropine oral?
- Store at room temperature of 68°F-77°F (20°C-25°C) in a child-resistant and light-resistant container.
- Follow storage and expiration recommendations for specially compounded formulas.
- Keep medication out of reach of children and pets.
What should I do in case of emergency?
If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Be prepared to provide information about the product and your pet's weight and symptoms. Report any adverse effects to the FDA or Health Canada.
© Copyright 2025 LifeLearn Inc. Used and/or modified with permission under license. This content written by LifeLearn Animal Health (LifeLearn Inc.) is licensed to this practice for the personal use of our clients. Any copying, printing or further distribution is prohibited without the express written consent of LifeLearn. This content does not contain all available information for any referenced medications and has not been reviewed by the FDA Center for Veterinary Medicine, or Health Canada Veterinary Drugs Directorate. This content may help answer commonly asked questions, but is not a substitute for medical advice, or a proper consultation and/or clinical examination of your pet by a veterinarian. Please contact your veterinarian if you have any questions or concerns about your pet’s health. Last updated on Sep 12, 2025.