The closure of Chinese factories that make the active ingredient in paracetamol means Pharmac will limit the amount of the government-funded drug patients can get from Monday.
Pharmac director of operations Lisa Williams said the factories in China making the active ingredient for the common painkiller had been closed due to the Covid-19 coronavirus.
She said there was enough stock in New Zealand to meet four months of normal demand.
Pharmac said temporary dispensing limits would allow the supplier, and potentially other suppliers if necessary, time to get additional stock until normal supplies of the raw material resumed.
Williams said that with the outbreak of Covid-19, it was inevitable that there would be disruptions to other drug supplies.
- If you have symptoms of the coronavirus, call the NZ Covid-19 Healthline on 0800 358 5453 (+64 9 358 5453 for international SIMs)
Williams warned more medicine shortages were inevitable.
"It's inevitable that there will be disruption across the supply chain so we're actively monitoring all products," she said.
"To make sure that where we need to take steps to ensure that all New Zealanders can access the medicines we need we'll put in place appropriate measures to ensure that will happen."
Read more about the Covid-19 coronavirus:
- Covid-19: What you need to know
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- Timeline: virus's spread across the globe
- Scientific hand-washing advice to avoid infection
- Coronavirus patient 'never really felt unwell'
- More Covid-19 news
The fourth case of the virus in New Zealand was confirmed today as the partner of the second confirmed case.
Authorities said the man in his 30s had attended a concert for the band Tool on Friday 28 February, having returned to New Zealand from a trip to Italy on the Tuesday.
Director-General of Health Dr Ashley Bloomfield assured people the risk of infection from the concert was low, but said if people had symptoms they should call the healthline instead of showing up at a GP or hospital.