Acetaminophen and Codeine for animals

Share this

Functional classification: Analgesic, opioid

Exact mechanism of action for acetaminophen is not known; however, a centrally  mediated mechanism is likely, either via inhibition of  central prostaglandin  synthesis or effects on serotonergic inhibitory pain pathways. In this formulation, the opiate codeine is added to enhance analgesia.   

Effects of codeine are not established  in animals. Systemic absorption of codeine from oral administration is small in dogs, and codeine  may play only  a minor role in analgesia.

Acetaminophen and Codeine for animals

Indications and Clinical Uses

Acetaminophen + Codeine is  used for analgesia in dogs (e.g., postoperative use). Codeine or codeine with acetaminophen is indicated for treatment of  moderate pain. Codeine formulations have also been used as an antitussive. Despite the widespread use of codeine in humans,  the efficacy in animals for its antitussive use or  analgesic use has not   been established. Oral absorption of codeine in dogs is low.           

Because codeine is converted to morphine (10% of dose) for its activity and the duration of morphine is short in dogs, the  clinical effectiveness  of codeine in dogs may be questionable.

Adverse Reactions and Side Effects

Acetaminophen + Codeine is  well tolerated  in dogs at doses listed; however, high doses  have caused liver toxicity.

Contraindications and Precautions

Do not administer to cats because acetaminophen is known to be toxic to cats. Codeine is a Schedule II controlled  substance.

Drug Interactions

In people, other drugs (especially alcohol) will increase risk  of hepatotoxicity. It is not known if other drugs increase this risk in animals, but consider this possibility when administering  other drugs that may affect  hepatic metabolism.


Instructions for Use

Many generic  preparations are available. Consider that other ingredients may be present  in some combination tablets (e.g., ibuprofen or        caffeine).

Patient Monitoring and Laboratory Tests

Monitor liver  enzyme levels  periodically to look for evidence of hepatotoxicity caused by acetaminophen.


Acetaminophen + Codeine is  available in oral solution and  tablets. A variety of formulations are available (e.g.,  300-mg acetaminophen plus   15-, 30-, or 60-mg codeine).

Stability and Storage

Acetaminophen is stable in aqueous   solutions. Maximum stability  is at pH of 57.

Small Animal  Dosage


Follow dosing recommendations for  codeine. Administer dose to deliver doses of codeine equivalent to 0.5-1.0 mg/kg q4-6h PO.


• Contraindicated.

Large Animal  Dosage

No dose has been reported for large animals.


Share this

Leave a Comment

Your email address will not be published. Required fields are marked *

error: Content is protected !!