Monitoring for toxicity involves regular clinical assessments and laboratory tests. For instance, patients on chloroquine should have periodic eye exams to detect early signs of retinopathy, while liver function tests are recommended for those on artemisinin-based therapies. In managing toxicity, the key strategies include dose adjustment, switching medications, and providing supportive care to alleviate symptoms. In some cases, such as severe mefloquine toxicity, discontinuation of the drug is necessary.