Prolongated means something that is stretched out or extended for a long period of time. If you want to use a different word, you could try elongated, which has a similar meaning. Other synonyms for prolongated include extended, lengthened, prolonged, continued, drawn-out, protracted, and stretched. Each of these words has a slightly different connotation, so you may want to choose the one that best suits your specific context. If you are looking for an antonym, try shortened, abbreviated, or truncated, which all mean the opposite of prolonged.