Medications can have unintended side effects, adverse effects, or toxic effects. Side effects may not be harmful, while adverse effects can damage organs over time and toxic effects can be life-threatening. The causes of harmful effects include overdose, interactions with other drugs or foods, illnesses impairing organ function, and allergic reactions. Treatment depends on the type of effect but may include inducing vomiting, gastric lavage, activated charcoal, reducing the dosage, discontinuing the drug, supportive treatments, and administration of antidotes.