SAN FRANCISCO (KPIX 5) — Pharmacies in the Bay Area are rationing the cough syrup that doctors prescribe for upper respiratory infections due to the severe flu season.

Because so many people have nasty coughs associated with the flu season, patients are likely to only receive half the dosage doctors prescribe.

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“It seems like all of San Francisco is sick,” Dr. Paul Abramson of My Medical Group told KPIX 5.

The pharmacists at a San Francisco Walgreens store wouldn’t speak on camera, but told KPIX 5’s Cate Cauguiran they are so strapped for the prescription medication Promethazine, which contains codeine, that they have been rationing it out to patients.

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Cate only received a fraction of the dose her doctor prescribed.

“It’s certainly very unusual that a generic medication like codeine with cough syrup would run out, but it doesn’t surprise me,” Dr. Abramson said.

Abramson says economic forces are likely behind the shortage because, “There’s not a lot of incentive for generic manufacturers to keep large stocks of reserves of medications, so they’re cutting it a lot closer so when there’s a big surge in demand, things just run out.”

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Pharmacies in Southern California were also experiencing shortages of the drug, according to sister station KCBS-TV.