Bronchodilators Now Available for Pets

Theophylline and aminophylline are used as bronchodilators in the treatment for cough and small-airway obstructive disease in canine and feline patients. In the past, veterinarians used commercially available theophylline time-released tablets, such as Theochron™ or generic products. At the end of 2015, manufacturers discontinued the commercially available tablets and capsules, which left a huge need in the veterinary community. Fortunately, compounders are able to take care of this need because of the availability of theophylline USP anhydrous powder.

As stated earlier, the commercial products were time-released. However, the formulas that we use are immediate-release preparations and not equivalent to the manufactured products. This is because canine and feline patients generally have faster gastric transit times than those found in humans. In canine patients, there is interbreed variability, with smaller breeds having faster transit times and larger breeds having transit times that are closer to those found in humans.

Vets and Pharmacists Working Together

At the North Carolina State College of Veterinary Medicine, pharmacists are working with clinic veterinarians, combining clinical experience and pharmacokinetic studies to determine dosing and frequency. In their practice, the veterinarians are using a compounded immediate-release capsule and dosing every 12 hours. Doses are based on weight: cats ~4-5 mg/kg and dogs ~9mg/kg. If a 12-hour dosing frequency does not control signs, then the dosage is given every eight hours. In clinical experience, however, this eight-hour frequency is required very rarely.

There have been some periods in the past when theophylline USP anhydrous powder was temporarily not available. In this instance, aminophylline may be substituted, but a conversion is required when switching from theophylline to aminophylline: theophylline 1 mg is equivalent to aminophylline 1.167 mg.

Aminophylline should be administered as an immediate-release preparation like theophylline. Any dosage change or dosage-form change, theophylline or aminophylline, should be monitored by owner and veterinarian so that adjustments can be made according to clinical response.

The content provided on this blog is for informational purposes only and should not be considered medical advice. Always consult with your physician regarding any questions or concerns you may have about your health.