It is customary to send thank you e-mails after your interview. Although hand-written cards have been recommended, I think sending e-mails are appropriate as well. It also can give you, the resident applicant an opportunity to redeem yourself if you missed something during the clinical component of an interview. From experience, if we do not know an answer, we often say, "I will have to look that up and get back to you." However, how many applicants actually contact their interviewers to follow-up? Sending a thank you is a great way to demonstrate follow-up and take initiative in correcting an error. For example, let's say you were asked why simvastatin is taken at night and you had told your interviewers that you would have to look that up. After the interview, you can send an e-mail.
Good morning Dr. XXXX,
I am writing to thank you for the opportunity to interview with your PGY1 pharmacy practice residency at XXXXX. In following up to your earlier question on simvastatin, the drug is thought to have a short half-life. Although the actual half-life is unknown, it is taken at night since most cholesterol is produced in the evening. Unlike other statins, such as atorvastatin with a half-life of 14 hours (metabolites 20 to 30 hours), these statins can be taken at any time during the day. This information was extracted from XXXX (package insert, guidelines, etc.)
Once again, it was a pleasure of meeting you and the residents. I enjoyed listening to their experiences, learning about your program, and meeting the preceptors.
I think following up with an answer, correcting a wrong answer with a citation of a guideline is an option to show the residency how you correct errors and extract information. Remember to send your thank you's in a timely manner as these may help leave a lasting impression after your interview.