Final answer:
Schedule V controlled substances in the U.S. can generally be refilled up to five times within six months, subject to federal and state regulations.
Step-by-step explanation:
In the United States, Schedule V controlled substances are subject to specific restrictions and regulations under the Controlled Substances Act. For prescriptions of these medications, federal regulations typically allow up to five refills within six months from the date of issue, provided that the refilling is authorized on the prescription and in accordance with state laws. However, individual states may have their own rules that either adhere strictly to these federal guidelines or impose stricter limitations. It is essential for both prescribers and patients to be aware of and comply with both federal and state laws regarding the handling of Schedule V controlled substances.