The Alka-Seltzer Plus Power Fast Fizz severe cold and flu citrus effervescent tablet dissolves quickly in hydrating water and is instantly ready to start working. Each dose is individually wrapped and transforms in just 4 oz of water into a liquid-fast medicine. After you drink the refreshing, sparkling solution, Alka-Seltzer Plus Power Fast Fizz works quickly to relieve your worst cold symptoms such as nasal and sinus congestion, cough, sneezing, fever, runny nose, headache, sore throat, body aches, and pains.