From the Guidelines
Furosemide is associated with several side effects, including increased urination, electrolyte imbalances, dehydration, low blood pressure, and increased blood sugar levels, as well as less common but serious side effects such as hearing problems, allergic reactions, and kidney problems, as reported in the most recent study 1.
Common Side Effects
- Increased urination: expected due to its mechanism of action to remove excess fluid from the body
- Electrolyte imbalances: particularly low potassium (hypokalemia), low sodium (hyponatremia), and low magnesium levels, which may cause muscle cramps, weakness, or irregular heartbeat
- Dehydration: manifesting as dizziness, extreme thirst, or dry mouth, especially if fluid intake is inadequate
- Low blood pressure (hypotension): resulting in lightheadedness or fainting, particularly when standing up quickly
- Increased blood sugar levels: important for diabetic patients to monitor
Less Common but Serious Side Effects
- Hearing problems or tinnitus: especially with high intravenous doses
- Allergic reactions
- Kidney problems: rare but potentially serious
Monitoring and Management
- Patients should maintain adequate hydration while taking furosemide
- Follow electrolyte monitoring as recommended by their healthcare provider
- Report concerning symptoms promptly
- Diuretic response should be defined as 1kg wt loss/day if oedema and 0.5 kg wt loss/day if no oedema, and diuretics should be temporarily discontinued if electrolyte imbalance, worsening hypokalaemia, hyperkalaemia, serum creatinine, hepatic encephalopathy, and muscle cramps occur, as recommended in the guidelines 1.
From the FDA Drug Label
ADVERSE REACTIONS Adverse reactions are categorized below by organ system and listed by decreasing severity Gastrointestinal System Reactions hepatic encephalopathy in patients with hepato-cellular insufficiency pancreatitis jaundice (intrahepatic cholestatic jaundice) increased liver enzymes anorexia oral and gastric irritation cramping diarrhea constipation nausea vomiting Systemic Hypersensitivity Reactions Severe anaphylactic or anaphylactoid reactions (e. g with shock) systemic vasculitis interstitial nephritis necrotizing angiitis Central Nervous System Reactions tinnitus and hearing loss paresthesias vertigo dizziness headache blurred vision xanthopsia Hematologic Reactions aplastic anemia thrombocytopenia agranulocytosis hemolytic anemia leukopenia anemia eosinophilia Dermatologic-Hypersensitivity Reactions toxic epidermal necrolysis Stevens-Johnson Syndrome erythema multiforme drug rash with eosinophilia and systemic symptoms acute generalized exanthematous pustulosis exfoliative dermatitis bullous pemphigoid purpura photosensitivity rash pruritis urticaria Cardiovascular Reaction Orthostatic hypotension may occur and be aggravated by alcohol, barbiturates or narcotics Increase in cholesterol and triglyceride serum levels Other Reactions hyperglycemia glycosuria hyperuricemia muscle spasm weakness restlessness urinary bladder spasm thrombophlebitis fever
The side effects of furosemide include:
- Gastrointestinal reactions: hepatic encephalopathy, pancreatitis, jaundice, increased liver enzymes, anorexia, oral and gastric irritation, cramping, diarrhea, constipation, nausea, vomiting
- Systemic hypersensitivity reactions: severe anaphylactic or anaphylactoid reactions, systemic vasculitis, interstitial nephritis, necrotizing angiitis
- Central nervous system reactions: tinnitus and hearing loss, paresthesias, vertigo, dizziness, headache, blurred vision, xanthopsia
- Hematologic reactions: aplastic anemia, thrombocytopenia, agranulocytosis, hemolytic anemia, leukopenia, anemia, eosinophilia
- Dermatologic-hypersensitivity reactions: toxic epidermal necrolysis, Stevens-Johnson Syndrome, erythema multiforme, drug rash with eosinophilia and systemic symptoms, acute generalized exanthematous pustulosis, exfoliative dermatitis, bullous pemphigoid, purpura, photosensitivity, rash, pruritis, urticaria
- Cardiovascular reactions: orthostatic hypotension, increase in cholesterol and triglyceride serum levels
- Other reactions: hyperglycemia, glycosuria, hyperuricemia, muscle spasm, weakness, restlessness, urinary bladder spasm, thrombophlebitis, fever 2
From the Research
Furosemide Side Effects
- The studies provided do not directly focus on the side effects of furosemide, but rather compare its efficacy and safety with other diuretics in various patient populations 3, 4, 5, 6.
- However, it can be inferred that furosemide, like other diuretics, may cause side effects such as fluid and electrolyte abnormalities, and acid-base disturbances 5.
- One study mentions that diuretics, including furosemide, predispose patients to serious cardiac arrhythmias and may increase the risk of arrhythmic mortality 5.
- Another study notes that furosemide and other diuretics may cause changes in the renin-aldosterone system, but does not specify the clinical significance of these changes 6.
- No significant differences in side effects, such as hospital readmission and mortality rates, were observed among different diuretics, including furosemide, in a systematic review and meta-analysis 5.