The account was previously handled by Campbell Mithun Esty, Minneapolis, which launched a print campaign for the drug two years ago.
Cline will launch ads for Zithromax's liquid form for children, which treats ear infections among other ailments. The tablet form for adults is used to treat respiratory infections such as pneumonia and bronchitis and skin infections.
The campaign from CME targeted parents and centered on Zithromax's five-day, once-daily usage regimen. By comparison, Zithromax's competitor in the broad-spectrum antibiotic category, Biaxin from Abbott Laboratories, has a 10-day recommended usage. Doctors sometimes turn to this new class of antibiotic when patients find Amoxicillin and Arithromycin ineffective.
Pfizer spent $18.2 million backing Zithromax last year, per Competitive Media Reporting, but spending has slowed this year to only $3.6 million through June.
Pfizer declined comment and it could not be determined whether the agency switch followed a review.
Pfizer this summer also moved its $75 million account for anti-allergy drug Zyrtec to Deutsch, New York, after a review.
Cline handles a number of Pfizer accounts, including high-profile erectile dysfunction drug Viagra.
This month, the agency launched a print effort for Diflucan, a drug that treats vaginal yeast infections. National TV starts Oct. 4. The campaign uses a new tagline: "Hate the yeast infection. Love the treatment."
Pfizer has heavily backed Diflucan since 1995, spending $15.3 million in 1997, per CMR, but that dropped to $671,000 last year.
Sales of both Pfizer drugs have experienced healthy growth. Diflucan reported $228 million in second-quarter revenues, an 8% jump from the same period last year.
Zithromax, introduced in 1992, rose 27% to $207 million in this year's second quarter. The drug had sales of $898 million last year, according to consultancy Scott-Levin. Abbott has declined to use DTC ads to promote Biaxin, which had