Final answer:
A CIII or CIV prescription is valid for six months from the date it was issued. State laws may impose stricter regulations, affecting the validity period and refill rules.
Step-by-step explanation:
A prescription for a schedule CIII or CIV substance is valid for six months from the date it was issued. Schedule III and Schedule IV drugs have a potential for abuse which is less than that of Schedule I or II drugs and which may lead to moderate or low physical dependence or high psychological dependence. Examples of such medications would include products containing not more than 90 milligrams of codeine per dosage unit (Tylenol with Codeine), and common sedatives like Lorazepam (Ativan).
After the six-month period, a new prescription is required. It is important to note that individual state laws can also affect the validity period of these prescriptions, possibly imposing stricter regulations, hence it's always essential to check the regulations in your specific state. Additionally, some states might have different regulations regarding the number of refills allowed on CIII and CIV prescriptions within this six-month period.