By Micah Maidenberg

McKesson Corp., a distributor of pharmaceuticals and medical supplies, said it built its financial forecast for fiscal 2021 under the assumption that a second wave of Covid-19 cases won't materialize.

The company said Wednesday in an investor presentation that its outlook for its 2021 reporting year assumes there won't be another rise in cases of the disease caused by the coronavirus that would lead "to shelter at home scenarios precluding patient consumption of healthcare services, supplies and pharmaceutical products."

The spread of the coronavirus in the U.S. kept consumers at home, putting pressure on patient visits to doctors and prescription growth, according to some companies that tie their business to prescriptions.

"We assume physician, specialty provider and oncology visits, and pharmacy interactions will gradually begin to resume in Q2 FY21, and continue to improve in the back-half of the fiscal year," McKesson said on Wednesday.

Overall, it expects adjusted earnings per share of no more than $14.75, which would be down from $14.95 a share for the year ended March 31. The company also sees slower revenue growth of 2% to 4% for the year, down from 8%.

Write to Micah Maidenberg at micah.maidenberg@wsj.com