(Reuters) – Eli Lilly and Co <LLY.N> on Friday priced its acute migraine treatment at $640 for a pack of eight pills and said it will be made available in pharmacies in the next few days.

The list price of a drug is not necessarily what patients actually pay. “Out-of-pocket” costs vary based on the duration of the treatment and individual healthcare plans.

Lilly expanded its migraine offerings in October by winning FDA approval for the therapy, Reyvow, but analysts had said that side-effects such as dizziness and sleepiness could limit its uptake.

Reyvow, intended to be taken after the onset of migraine, could be used as often as every month or as little as a couple of times a year, the company said.

More than 30 million Americans live with the disease, which is characterized by recurrent episodes of moderate-to-severe headache accompanied by other symptoms, including nausea and light sensitivity.

A class of drugs called triptans are commonly prescribed for treating acute migraine.

The company said Reyvow was cleared by the Drug Enforcement Administration with a “Schedule V” classification – the lowest of the five schedules – marking it as a chemical with low potential for abuse.

Patients are advised to not drive or operate machinery for at least eight hours after taking Reyvow.

(Reporting by Saumya Sibi Joseph in Bengaluru; Editing by Arun Koyyur)