Drug caution codes: Abbreviations on medications that indicate caution. While not a part of the historical heritage of ancient prescription abbreviations, drug caution codes provide very valuable warnings.
They include both universal and specific caution codes:
These special caution codes are intended to be warnings for patients with specific medical conditions. For example, a person with hypertension might see the generic "C" code on a prescription bottle or vial if the medication might raise his or her blood pressure.
If you see one of the universal or special caution codes on a prescription, talk to your pharmacist about it before using the medicine.
In the United States and some other countries, a system of stickers with pictographs is also used to warn of side effects such as drowsiness.