Dr. Robert Strang says health officials are considering ways to make the stockpile of Tamiflu last. (CBC)Nova Scotia health officials are trying to figure out what to do with a stockpile of Tamiflu that is set to expire this summer.

The province spent $1.2 million on the antiviral drug when the H1N1 pandemic struck in 2009.

Only 18 per cent of it was used. Nearly one million doses remain stockpiled in a government warehouse.

"We made decisions about how much antivirals to use well before H1N1 hit, making some assumptions about potential severity and the percentage of the population that could become ill," said Dr. Robert Strang, the province's chief public health officer.

"Fortunately, we never reached anywhere close to those numbers for H1N1. But part of it is we have to be prepared. The next pandemic could be more severe."

After the outbreak ended, the province took back doses from pharmacies, hospitals and communities. Boxes of unused Tamiflu ended up in the drug distribution centre.

About 19 per cent of the stockpile has already expired, and the rest is only good until August.

Nova Scotia used about 18 per cent of its Tamiflu order. (CBC)

Strang said health officials are looking at their options, including finding ways to make the stockpile last.

"Do we replace it? How much do we replace?" he said. "Are there ways that we can extend the shelf life?"

Tamiflu is said to diminish the symptoms of H1N1 if it's taken within the first 48 hours.

According to a CBC documentary, some researchers in Canada, Italy, Britain and the U.S. are now challenging the claims by the manufacturer that Tamiflu can significantly reduce complications or hospitalizations.

The documentary also raises concerns about possible side effects, such as psychiatric delusions, that some countries have reported.

Strang said health officials in Nova Scotia consult other health experts before making decisions.

"We're going to work with our colleagues across the country to come to some consistent decisions based on the best available evidence," he said.

While Strang said he wouldn't want to do without antiviral drugs, he stressed that Tamiflu is only one part of a pandemic response that relies heavily on prevention.

"[We're] trying to find what's the appropriate investment in antivirals knowing that we've got to invest in other areas in terms of vaccine, immunization, better surveillance systems — a whole range of things."