Combining what two substances can have harmful effects on an individual's health?

Combining alcohol and medications can have particularly harmful effects on an individual's health. Alcohol can alter the way medications are metabolized and affect their effectiveness. Some medications can enhance the sedative effects of alcohol, leading to increased drowsiness, impaired coordination, and an elevated risk of accidents. Others may cause serious and potentially life-threatening reactions when taken with alcohol, such as respiratory depression or cardiovascular complications.

In contrast, while drinking alcohol with water may dilute the alcohol and potentially lessen its immediate effects, it does not create harmful interactions like certain medications. Caffeine and sugar can affect energy levels and alertness, but they are not associated with the same level of risk as the combination of alcohol and medications. Similarly, while nicotine and alcohol can both have addictive properties and impact health negatively, they do not carry the same immediate danger as mixing some medications with alcohol.