There are two general classifications of drugs: prescription only (Rx only) and over-the-counter (OTC).
Prescription only drugs are only available with a valid prescription from a prescriber. These drugs are heavily regulated and require a visit to a prescriber, a diagnosis and monitoring by a prescriber to ensure the medication is working and that it is working safely.
Prescription drugs are intended for use by one individual patient to treat a specific condition and when starting the medication each patient is legally entitled to speak with a pharmacist about the drug. Prescription drugs must pass through many clinical trial phases, approval by the Food and Drug Administration (FDA), and monitored for safety and side effects even after the drug is on the market.
Over-the-counter drugs are available for purchase without a prescription and can be purchased right off the shelves at a store - without a visit with a prescriber or consultation with a pharmacist. OTC medications are not intended for a specific individual, although depending on the medication, such as creams, eye drops or nasal sprays, the user may want to be the only consumer of the medication.
OTC drugs are monitored by the FDA, but it is not as strict as the process prescription drugs must go through. Manufactures are required to make drugs only based on a specific formula with regards to the strength of the drug and they must have FDA approved labeling and FDA specific dosage to be on the market.
Although OTC drugs are available without consulting with a prescriber or pharmacist, the patient needs to be aware these drugs still carry a risk. Some OTC drugs could cause drug interactions with prescription medications or cause more adverse effects. It is important to mention to a prescriber or pharmacist about all of the OTC drugs being used and to follow the recommended dosing instructions on the label.