Warnings. Extra-strength. Generic. Enteric. Timed-release. Combination formula. Active ingredients. These are just some of the terms youll see on the labels of over-the-counter pain relievers. People sometimes think that because they can obtain OTC pain medications without a prescription, these medications are safer than prescription drugs, says Meghan Lehmann, RPh, Pharm.D, BCPS, a drug information specialist at Cleveland Clinic. They may not be aware that OTC drugs can cause side effects, interact with other prescription or OTC medications, and have maximum daily dosing recommendations.