Patients in Hurricane Florence's path should refill their prescriptions before the pharmacy chain starts closing stores in evacuation zones, CVS Health said Tuesday.

The company is texting and emailing patients to remind them to refill prescriptions before the Category 4 storm hits. Florence is expected to approach North Carolina or South Carolina Thursday and Friday, causing flooding between a "dangerous" storm surge and up to two feet of rain, according to the National Oceanic and Atmospheric Administration's National Hurricane Center.

More than 1.5 million people have already been ordered to evacuate. In the meantime, people who need to refill prescriptions can do so at the chain's other locations.

Patients whose prescription drug benefits are covered by CVS' pharmacy benefit manager, Caremark, are eligible to receive a one-time emergency refill of a 10-day supply in impacted areas. Aetna, the health insurer that CVS is in the process of acquiring, is allowing members to refill their prescriptions early, if needed.

A Walgreens spokesman said the company encourages patients to follow evacuation orders. They can refill their prescriptions at any of its pharmacies nationwide, he added.

Health insurer Cigna has lifted refill requirements in Maryland, North Carolina, South Carolina, Virginia, Washington, D.C. and West Virginia through Oct. 10. For patients in North Carolina, South Carolina and Virginia, Cigna will be more flexible with prior authorizations, pre-certifications and referrals for medical care and filing claims. The insurer will cover out-of-network services at the same level as in-network services through Sept. 25.