Lasix (Furosemide) Overview, Dosage, How to Take, Side Effects and Warnings

Lasix (Furosemide) dosage. Never stop taking Lasix or alter your dose without your doctor’s approval. Adults who have fluid retention problems will typically begin with a single dose of 20 milligrams (mg) to 80 mg. The dose in children will vary based on what your doctor deems appropriate. Adults who have high blood pressure often begin with 40 mg, twice per day. The dosage may be adjusted for elderly patients.