Which of the following types of medications does NOT require a doctor's order?

Topical medications are often used for localized treatment and may not always require a doctor's order. These medications include creams, ointments, or gels that can be applied directly to the skin for conditions such as rashes, eczema, or localized pain relief. In many cases, over-the-counter topical medications can be used without a prescription, as they are considered safe for general public use when applied appropriately.

In contrast, prescription medications, controlled substances, and injectable medications typically require a doctor’s order due to the potential for misuse, more complex administration routes, or the need for professional oversight concerning dosage and monitoring of effects. Thus, the lack of requirement for a doctor's order makes topical medications distinct in this context.