Drug Classification & Information

Doxycycline is an antibiotic that is classified as a tetracycline.

Indications for Use

Doxycycline has become an important part of the protocol for treatment of heartworm infections in dogs.  It treats a bacterium known as Wolbachia that lives with the adult heartworms.  Studies revealed that dogs treated with doxycycline had fewer complications post heartworm treatment compared to those who did not receive it.  It is suspected that Wolbachia may play a role in some of the complications in dogs treated for heartworm disease.  It also has good activity against Mycoplasma, a common airway pathogen and has some unique anti-inflammatory properties that be beneficial in patients with bronchitis. Commonly used to treat tick borne illness.

Potential Drug Interactions

No significant drug interactions are reported.

Drug Side Effects

The most common side effect is gastrointestinal with reduced appetite, vomiting, diarrhea.  When given with food, this may help to reduce this GI side effects.  Has been associated with esophagitis – therefore each dose should be followed by water or food to avoid this risk (monohydrate may be less irritating than the hyclate form).  Can increase liver enzymes so caution in patients with liver disease.  Tetracyclines can cause bone and teeth development issues so caution in young animals.

Therapeutic Monitoring

When used in patients with bronchitis, monitor for improvement in cough frequency.

Dosage Forms

Human: 50, 75, 100, 150 mg tablets & capsules