Study Start Date: 5/25/2006
Study End Date: 8/2/06

Transdermal gel drug absorption in dogs and cats

Studies have demonstrated that single doses of transdermal gels appear to be insufficient in increasing plasma or serum drug concentrations. However, drug delivery may be more predictably effective with multiple dosing, once steady-state has been achieved (as has been shown for methimazole). Additionally, efficacy needs to be demonstrated for any drug delivered by this method, in the target species. The simplest way to prove effective delivery of a drug in a patient is by detecting therapeutic concentrations in the blood following administration of the drug using the gels.

We are looking for patients currently receiving the following drugs either orally or transdermally and whose owners will allow the collection of two samples post-dosing: enrofloxacin, metronidazole, prednisolone, fluoxetine, amitriptyline, clomipramine, buprenorphine, and cyproheptadine. We will compare plasma or serum drug concentrations between the oral and transdermal groups for each of these drugs.

Inclusion criteria:
Dogs or cats receiving one of the listed drugs either orally or transdermally for a minimum of 5 drug half-lives.

Exclusion Criteria:
Dogs or cats receiving one of the listed drugs for less than 5 half-lives.

Samples:
Two blood samples will need to be obtained at pre-specified periods. Sampling kits will be mailed out to the veterinarian, along with an instruction sheet and shipping information.

Costs/Reimbursements:
The investigators will pay for shipping sample tubes to clinicians, and return shipping.

Full Disclosure information:

• The study is funded by a grant from Merck and Merial.
• The investigators do not have any conflict of interest.
• The study will be published if results are negative
• The study will be reported on VIN
• The authors will acknowledge VIN if the study is published