** Thanks for contacting HCM with your health concern 1. Lasix [furosemide] is a loop diuretic used to treat build up fluid/swelling [oedema] in conditions like heart failure,liver cirrhosis,kidney problems and dose is adjusted according to response 2. As use of laxis is frequently associated with hypotension, fluid & electrolytes imbalance, thus could be the possible culprit however take him to emergency where the attending Doctor has to rule out other cause(s) of low blood pressure like: gastroenteritis, myocardial infarction,septic shock 3. in between: . give head low position . start intravenous line with Ringer lactate . If there is evidence of infection give antibiotics . shift immediately to hospital if heart attack is suspected