for a prophylactic dose of antibiotics after having a tick latched for an unknown amount of time

the US gets a persistent amount of emergency room visits for this sort of treatment (tens of thousands annually), and with all the news about increased tick and lyme exposure a larger number of people treat it preemptively, especially with children

Hm, that approach would have me at the doctor every second day and being on antibiotic all the time. I am outdoors a lot and had 5 ticks on me just today after not checking enough last night after being outside.

I only would consider antibiotics if the red ring appears. In general I suppose I already have resistance .. or the disease slumbering in my body.

Same. I've found engorged ticks a half dozen times in my life. Never had the red ring and never had antibiotics for it. I've got hypothyroidism (genetic) and some mental health issues, but I am otherwise healthy and run 15 miles a week.

I really don't believe that the vague long term symptoms a lot of people are describing in this thread are from ticks, especially people who don't spend much time outside in lyme endemic regions. Lyme has become a favorite label for quacks to describe the fatigue/pain syndrome that is sometimes called fibromyalgia. We don't really know what causes it (and it's probably not ticks), and taking high dose doxycycline for months is not the answer, other than maybe as a placebo.