Pseudoephedrine (Sudafed®, Equiphed®) for Dogs and Cats

Overview of Pseudoephedrine for Canines and Felines

Pseudoephedrine HCL, commonly known by the brand names Sudafed® or Equiphed®, is a drug used in dogs to increase urethral tone abnormalities and can be use in cats to treat respiratory problems like bronchitis and nasal congestion.

• The therapeutic dose and toxic dose ranges are close making this drug an unpopular choice for many pets. Some suggest this drug should NOT be used in dogs. All pets receiving Pseudoephedrine should be carefully monitoring for signs of toxicity.
• Pseudoephedrine is a central nervous system stimulant classified as a sympathomimetic alkaloid agent and is similar to ephedrine.
• Pseudoephedrine causes the release of the sympathetic nervous system chemical norepinephrine. The involuntary nervous system is divided into the sympathetic (flight or fight response) and parasympathetic branches. In general, these two systems oppose each other.
• When stimulated, the sympathetic system increases heart rate, blood pressure and cardiac activity. It also dilates the bronchial tree and contracts certain smooth muscles.
• When compared to ephedrine, pseudoephedrine has only 25 percent the effect on blood pressure and 50 percent the effect on dilating airways.
• This drug is not approved for use in animals by the Food and Drug Administration but it is prescribed legally by veterinarians as an extra-label drug.
• Pseudoephedrine is available without a prescription but should not be administered unless under the supervision and guidance of a veterinarian.

Brand Names and Other Names for Pseudoephedrine

• Pseudopseudoephedrine is available in many different over-the-counter (OTC) products. It is also commonly available in combination with other drugs, such as decongestants and cold remedies.
• This drug is registered for use in humans only.
• Human formulations: Pseudoephedrine is supplied by numerous drug companies with a variety of trade names and various generic formulations. Common brand names include Sudafed and Equiphed.
• Veterinary formulations: None

Uses of Pseudoephedrine for Dogs and Cats

• Pseudoephedrine is used in dogs to treat urethral sphincter tone.
• It can also be used for its bronchodilator activity, pseudoephedrine has been used in the treatment of respiratory conditions like bronchitis and nasal congestion in dogs; however, other drugs such as theophylline and terbutaline are more often prescribed and safer for dogs.

Precautions and Side Effects

• While generally safe and effective when prescribed by a veterinarian, pseudoephedrine can cause side effects in some animals.
• Pseudoephedrine should not be used in animals with known hypersensitivity or allergy to the drug.
• Little information is available on the safety of pseudoephedrine use in cats. For this reason, use in cats should be avoided.
• Pseudoephedrine may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with pseudoephedrine.
• Common side effects associated with pseudoephedrine include nausea, loss of appetite, vomiting, changes in behavior (agitation, restlessness), increased heart rate, muscle tremors and seizures.
• Pseudoephedrine should be avoided in animals with hyperthyroidism, glaucoma, diabetes mellitus, hypertension and disorders of the cardiovascular system.

How Pseudoephedrine Is Supplied

• Pseudoephedrine is available in 30 mg and 60 mg tablets. It is also available in 120 mg capsules.
• Pseudoephedrine syrup is available in a 6 mg/ml concentration.

Dosing Information of Pseudoephedrine for Dogs

• Medication should never be administered without first consulting your veterinarian.
• For urethral tone problems in dogs, Pseudoephedrine is dosed at 0.75 mg per pound (1.5 mg/kg) orally every 8 to 12 hours. For respiratory symptoms, the dosage in dogs is 0.1 to 0.2 mg per pound (0.2 to 0.4 mg/kg) or 15 to 60 mg per dog by mouth every 8 to 12 hours.
• In cats, it is dosed at 0.5 mg per pound (1 mg/kg) orally every 8 hours.
• The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.