Which of the following constitutes unprofessional conduct in prescription practices?

The act of prescribing drugs in excessive amounts is considered unprofessional conduct because it poses significant risks to patient safety. Overprescribing can lead to potential drug dependence, negative side effects, and adverse reactions due to high dosages. This behavior signals a lack of adherence to established medical guidelines and standards meant to ensure patient welfare. It undermines the trust placed in healthcare professionals and can contribute to a wider public health issue, such as the opioid epidemic.

The other options, while also concerning, do not specifically highlight the excessive aspect of medication prescriptions. For instance, failing to inform patients about side effects may compromise informed consent but does not directly relate to the quantity of medication prescribed. Similarly, refusing to prescribe necessary medications can indicate issues with access or standards of care, and giving incomplete medical histories can disrupt optimal patient care but do not inherently relate to the concept of excessive prescription practices.