The future tense is "will triplicate".
I need you to file these forms in triplicate.
The form must be filled out in triplicate.
Trouble in Triplicate has 186 pages.
Trouble in Triplicate was created on 1949-02-11.
Triplicate. eg This letter should be done in triplicate.
The word you're looking for is... triplicate.
It depends on what you mean by "triplicate" prescription. Are they writing three prescriptions or are they writing out the third prescription for the same medication. Assuming the former, if the doctor deems it medically necessary to give you three prescriptions, they absolutely can. On the latter, yes and no, the Doctor would be curious as to why your medicine keeps disappearing and depending on the type of prescription (mainly narcotics) can only prescribe so many per a certain time.
triplicate
He had to fill out the forms in triplicate - one set for the office, one for himself, and one for the agent.
If 3 is triplicate, then 5 is quintuplicate. In mathematical terms, "triplicate" means three of something, while "quintuplicate" refers to five of something. So, if we follow that pattern, 5 corresponds to quintuplicate.
triplicate