Lasix is a diuretic and antihypertensive medication that contains furosemide. It is prescribed to treat high blood pressure and fluid retention caused by heart disease, liver disease, kidney disease, or severe burns. Lasix is especially useful for managing serious cases of heart failure, liver failure, and kidney failure.
You can obtain Lasix from pharmacies in tablet form, available in strengths of 20 mg, 40 mg, and 80 mg. This medication should only be used under medical supervision and guidance. Your doctor will determine if Lasix is appropriate for your condition and prescribe the right dose for you.
In hospital settings, Lasix can also be given by injection, which is administered by a nurse under direct medical supervision. This injectable form allows for quick administration in emergency or acute care situations where rapid fluid removal is necessary.
What is Lasix used for?
Your doctor may prescribe Lasix to treat swelling or fluid retention in the body caused by several medical conditions, including:
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Acute and chronic congestive heart failure
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Acute heart failure
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Liver disease
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Acute kidney failure
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Nephrotic syndrome
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Severe burns
Beyond treating fluid retention, Lasix is also prescribed to manage high blood pressure and hypertensive crises, helping patients maintain healthier blood pressure levels.
How it works
Lasix works by increasing the amount of sodium your kidneys eliminate. When sodium leaves your body through urine, water follows it out as well. This process reduces the overall amount of fluid in your bloodstream, which lowers blood pressure and decreases swelling throughout your body.
Lasix produces a strong diuretic effect that begins working quickly and lasts for a relatively short time, making it effective for managing acute fluid overload situations.
Does Lasix help with weight loss?
You may notice that your weight decreases after starting Lasix treatment. This happens because the medication removes excess fluid that has built up in your body, not because it burns fat. For this reason, Lasix is not intended or recommended for weight loss purposes. The medication does not affect fat metabolism or body composition.
Because Lasix can cause many side effects and is not designed for weight management, you should never use it for weight loss. If you are interested in weight loss options, talk with your doctor about safer, more appropriate treatments specifically designed for that purpose.
How to take
The way you take Lasix depends on which form your doctor prescribes. Here are the details for each type:
1. Lasix tablets
Take Lasix tablets by mouth with a full glass of water on an empty stomach. Take your dose either one hour before eating or two hours after you finish eating, as food can interfere with how well your body absorbs the medication.
For adults starting Lasix treatment, doctors typically prescribe an initial dose of 20 mg, 40 mg, or 80 mg once daily, depending on your specific condition and how your body responds. Once your condition stabilizes, most adults take a maintenance dose of 20 to 40 mg daily.
For children, the typical recommended dose is 2 mg per kilogram (kg) of body weight, with a maximum daily dose of 40 mg. A pediatrician will always determine the appropriate dose for a child based on their age and weight. Your doctor will tell you how long you should continue taking Lasix, as treatment duration depends on your individual medical needs.
2. Lasix injection
Lasix injection comes in a concentration of 10 mg per milliliter (mL) and is only given in a hospital or medical facility. A nurse will administer the injection directly into a vein or muscle under a doctor's supervision.
Your doctor will determine the injection dose based on your medical condition and how severe your symptoms are. Most adults receive an initial dose between 20 mg and 40 mg. When Lasix is prescribed for children in injectable form, a pediatrician calculates the appropriate dose according to the child's body weight.
Possible side effects
Common side effects that may occur while taking Lasix include diarrhea, constipation, loss of appetite, numbness, tingling sensations, headache, dizziness, and blurred vision. These effects are often mild and may decrease as your body adjusts to the medication.
Some side effects from furosemide require immediate attention and should be reported to your doctor right away. These include increased thirst, dry mouth, stomach pain, nausea, vomiting, yellowing of your skin and eyes, nervousness, irritability, irregular heartbeats, muscle cramps, and muscle weakness. These symptoms suggest that the medication may be affecting your electrolyte balance or other important body functions.
Lasix can sometimes cause serious allergic reactions that demand emergency medical care. Stop taking Lasix immediately and call emergency services or go to an emergency room if you develop any of these symptoms: trouble breathing, throat tightness, swelling of your mouth, tongue, or face, hives, blisters on your skin, burning eyes, or a severe sore throat.
Contraindications for use
Do not take Lasix if you have a known allergy to furosemide or any other ingredients in the medication.
Your doctor should not prescribe Lasix if you have certain medical conditions, including:
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Kidney failure with no urine output
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Liver failure
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Hepatic precoma or coma caused by liver disease
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Low blood levels of potassium or sodium
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Severe dehydration
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Low blood volume
Lasix requires special consideration during pregnancy. While your doctor may prescribe it if the benefits outweigh the risks, furosemide can cross the placenta and reach your developing baby. If you take Lasix during pregnancy, your doctor will monitor your baby's development closely throughout your pregnancy.
Do not take Lasix while breastfeeding. Furosemide passes into breast milk and can potentially reduce milk supply or affect your nursing infant.
Food can reduce how much furosemide your body absorbs, so always take your Lasix tablets on an empty stomach for the best results.