I've used this pharmacy monthly for a couple of years now.
I'm sure you're right about them supplying hospitals, clinics etc. as there are often customers in there with huge database printouts to be filled.
Tried different times of day, unsuccessfully, to find a quieter time . At least 10 assistants rushing around like ants.
Brings my monthly medication bill from Bangkok Christian hospital down from 3K to 1.2K Baht.
Hint ---- write your needs on a piece of paper and stand looking helpless and an assistant will take pity on you.
Make sure you get the correct pharmacy as there are several in that short strip of Rama 4.
Details from their card:
Chula Phesaj
942/25 Rama 4 Suriyawong, Bangrak BKK 10500
Open Mon-Sat 08:30-8:00 pm email
chulapessaj@gmail.com. phone 02 233 5105 (and in that quaint Thai way several other numbers).