How long is a prescription valid in India? No general expiry is written in law. What rule 65 says about repeats, and how to write a refill so a chemist can honour it.

Indian law fixes no general validity period for a prescription. We read rule 65 of the Drugs and Cosmetics Rules, 1945, the rule that governs what a retail chemist may dispense and how, and it contains no clause that says a prescription expires after a set number of days or months. What it does say is how many times a prescription for a Schedule H, H1 or X medicine may be dispensed: once, unless the prescriber has written on it that it may be dispensed more than once, and then only as many times or at such intervals as the prescriber stated. The practical limit on a prescription is therefore the quantity and duration you wrote and the repeat instruction you did or did not add.

This post is about the chemist's rules. It says nothing about how long a course of any medicine should run; that is your clinical call and outside what we write. What must be on the page before a chemist can fill it is in what must a prescription contain.

What does rule 65 say about dispensing a prescription?

Rule 65(9)(a) says substances in Schedule H, Schedule H1 and Schedule X "shall not be sold by retail except on and in accordance with the prescription of a Registered Medical Practitioner". Rule 65(10) defines the prescription: in writing, signed with the usual signature and dated, naming the patient and their address, and indicating "the total amount of the medicine to be supplied and the dose to be taken". Rule 65(11) then sets the dispensing conditions:

(a) the prescription must not be dispensed more than once unless the prescriber has stated thereon that it may be dispensed more than once; (b) if the prescription contains a direction that it may be dispensed a stated number of times or at stated intervals it must not be dispensed otherwise than in accordance with the directions; (c) at the time of dispensing there must be noted on the prescription above the signature of the prescriber the name and address of the seller and the date on which the prescription is dispensed.

Read together, the three clauses answer the validity question without a date. A prescription with no repeat instruction is spent once the chemist dispenses it and writes the seller's name and date on it under clause (c). A prescription with a repeat instruction is good for the number of times or the intervals you wrote. Nothing in the rule says a chemist must refuse a first-time dispensing because the date on the prescription is old; nothing says the chemist must accept it either. Rule 65(11-A) adds that the chemist may not substitute "any other preparation, whether containing the same substance or not" for what you prescribed.

Which time limits do exist in the rules?

The periods written into rule 65 are about records, and they fall on the chemist or on a doctor who dispenses, not on the patient's copy.

How do you write a prescription a chemist can refill?

Because rule 65(11)(a) defaults to once, a refill has to be explicit on the page. The rule gives two forms, a stated number of times or stated intervals, and the chemist must follow whichever you wrote.

1. Write the quantity and duration for one supply, as rule 65(10)(c) requires: the chemist works out strips from this.
2. If you intend a repeat, write it on the prescription in words the chemist cannot misread: "May be dispensed twice" or "May be repeated monthly for three months". Put it near the medicine lines, not in a corner.
3. If the repeat applies to some medicines and not others, say which. A single instruction at the bottom reads as applying to all.
4. Sign and date as usual. Rule 65(11)(c) means the chemist will write their name, address and dispensing date on the page each time, so leave room above your signature.
5. Keep a copy. Regulation 1.3.1 of the 2002 conduct regulations and the 72-hour rule in 1.3.2 apply to prescriptions you issued; see how long to keep medical records.

What should the clinic tell a patient with an old prescription?

At most OPD desks this comes up as a phone call: the patient is at a chemist with a parchi from months ago and the chemist has said no. The honest answer is in two parts. If the prescription was already dispensed and carries no repeat instruction, the chemist is applying rule 65(11)(a), and the patient needs a fresh prescription. If it was never dispensed, or it carries a repeat that has not been used up, the rules do not bar the chemist, but whether to dispense from an old prescription is the chemist's judgement and, for the medicine itself, yours; the desk should not promise either way. A follow-up visit settles it.

Online pharmacies and chains often apply their own cut-off on the age of a prescription. That is a business policy layered on top of rule 65, and it changes from seller to seller, so do not quote a number of days to patients as if it were law.