Ans. Quinine causes unpredictable, serious, and life-threatening blood and cardiovascular reactions. It includes low platelet count and hemolytic-uremic syndrome, long QT syndrome, and other serious cardiac arrhythmias. The most common adverse effects involve a group of symptoms called cinchonism, which can include headache, vasodilation and sweating, hearing impairment, nausea, vertigo or dizziness, blurred vision, and color blindness. Cinchonism is less common when quinine is given by mouth, but the oral prescription is not well tolerated due to its extreme bitterness. It may lead to vomiting after ingesting quinine tablets. Other drugs such as Fansider or Malarone are often used when oral therapy is required. Here, blood glucose, electrolyte, and cardiac monitoring are not necessarily required when quinine is given by mouth.