Common side effects include weakness, muscle cramps, fatigue, dizziness, fainting, confusion, irregular pulse, nausea, diarrhea and vomiting.
Technically Lasix belongs to a class of drugs known as loop diuretics, which will cause the body to excrete water as well as potassium, sodium and chloride. Loop diuretics including Lasix are among the strongest such drugs available, having an extremely dramatic effect on fluid levels in the body. Potassium levels need to be particularly watched, Lasix greatly increasing the amount excreted. The use of a prescription potassium supplement therefore is often required to keep levels in balance, otherwise a serious heart complications might develop. Mistakes in potassium dosage have equally serious consequences, so Lasix is clearly a risky item to use.