As a practical matter, pharmacists in California already provide written warnings on medications dispensed. Now California law expressly requires pharmacists to include written labels on prescription drug containers indicating that the drug may impair the ability to operate a vehicle or a vessel and that it poses a significant risk if consumed with alcohol. Failure to provide such warnings may result in citation and fine.

The regulation also identifies specific classes of drugs that may impair a person’s ability to drive a vehicle and that pose a substantial risk when taken in combination with alcohol. Pharmacists must also include warnings if based on their professional judgement a drug may need it. Thus it is safe to include the warning on all prescription drugs dispensed.

Link to the amended regulation: 

Keep in mind that warnings such as this: “If you drink alcohol, discuss the safe use of alcohol while taking this medication with your healthcare professional” – do not comply with the new regulation (and I’ve seen quite a few of them). While this warning: “Do not drink alcoholic beverages while taking this medicine” will suffice.