Medical supplies, including treatments for chronic illnesses, are not themselves subject to U.S. sanctions on Iran but pharmacies in Iran are having difficulties keeping their shelves stocked with the medicines that people, particularly those with chronic illnesses, depend on. Medication prices are soaring in Iran and some treatments have become hard to find, leaving patients and their families scrambling, AP reported on Wednesday. Some medicines have more than tripled in price, further squeezing Iranians’ finances.

Iran’s pharmaceutical industry is vulnerable because of its reliance on imports. So far there has been little sign of major shortages of medicines at Iran’s hospitals, but the difficulties are showing at pharmacies.

Iran produces more than 80% of its medicines domestically, according to official statistics, but many of those rely on imported raw materials. Before the war, most medicines and pharmaceutical components were brought in by sea, but the American naval blockade has cut off shipping, Bahman Sabour, a member of the Tehran Pharmacies Association, told local media. Medical importers switched to more expensive air routes. But that access has been threatened by new U.S. sanctions on a number of Iranian airlines, which led to some international flights being halted.