Common over-the-counter painkillers that contain codeine could become prescription-only.

The Medicines Classification Committee will decide in May whether to tighten the rules on the pills.

If they are restricted, as pseudoephedrine-based medicines were in 2011, it would mean fewer cold and flu medicine choices for over-the counter consumers.

Codeine is in dozens of easily available cold, flu or pain medicines but is an addictive opioid.

Under current rules, such medicines can be bought only from a pharmacist and any purchase must be recorded.

Australia last year announced plans to make codeine-based drugs prescription-only from 2018, and that prompted Medsafe to look at changes in New Zealand.

Auckland's Community Alcohol and Drug Service said it had seen an increase in people with addictions to codeine based medicines - including one person who had been taking a potentially lethal 90 Nurofen-Plus tablets a day.

The centre's clinical leader, Susanna Galea-Singer, wanted greater restrictions - at the very least.

"We are seeing a gradual increase and we don't want this to become a crisis before we act on it. We're just trying to be proactive here," Dr Galea said.

Capital and Coast District Health Board addiction psychiatrist and clinical lead Sam McBride said the service tended to see people who fell into two camps - those who had become addicted to daily use or those who binged.

He supported the change to prescription only.

In countries like the United States the problem had got out of hand, with huge death rates from legal opioids, he said.

"In New Zealand we've been slightly ahead of the game and better prepared but I don't think it's a problem we can afford to ignore."

The Self Medication Industry Association, which represents the biggest players in over-the-counter medicines - including the manufacturers of Nurofen Plus, Panadeine and Codral - said the vast majority of the population used the medication properly and well.

Executive director Scott Milne said forcing consumers to go to the doctor was not the answer and would be unfair on consumers.

"It's time consuming and it's much more expensive. They either pay a doctor's fee or the government pays a doctor's fee. What we want to do is make sure we have sensible tools available for self-medication where appropriate."

A better solution would be a centralised computer system that kept track of sales so addicts or abusers could not go to multiple pharmacies to get their fix, he said.

Many of the problems with opioids in the United States were from prescription pills, which Mr Milne said showed that going through doctors did not necessarily solve the problem.

As well as the prescribing option, the Medicines Classification Committee will look at a range of options when it meets next month, including keeping the status quo, restricting packet size or adding warnings.