Final answer:
Prescriptions without a prescriber's handwritten signature or initials are generally invalid, with the exception of some emergency cases. OTC drugs do not require prescriptions, and it is not the pharmacist's role to sign prescriptions.
Step-by-step explanation:
Written prescriptions without a prescriber's handwritten signature or initials are generally considered invalid. A valid prescription for a controlled substance must include certain elements, such as the prescriber's signature. However, there are certain circumstances where an electronic or digital signature may be accepted, which align with regulations set forth by organizations like the Drug Enforcement Administration (DEA) in the United States. For OTC drugs, prescriptions are not necessary as they can be purchased over-the-counter without a prescription. In emergency cases, a verbal prescription may be accepted, but it must be followed by a written prescription with the prescriber’s signature within a specified period. It is not the pharmacist's role to sign a prescription to validate it; their role is to review and dispense the medication as prescribed.