Prescription cough syrup contains codeine, which is an opiate. Moreover, companies add it to the cough medicine to help with the pain that manifests from a persistent cough. In addition, the drug can also suppress a cough.

In small doses, codeine is effective in relieving pain. In large amounts, however, it causes a state of euphoria. The drug is also very addictive. To discourage abuse, most prescription cough syrups have an unpleasant flavor.

Those who want to abuse it to get high add soda to avoid the bad taste. It also increases people’s risk for overdose because it’s easy to lose track of how much they drink. Before they know it, they’ve had too much.