What is Lasix® (furosemide) used for?
Lasix® is a loop diuretic (water pill) that prevents your body from absorbing too much salt. This allows the salt to instead be passed in your urine.
Lasix® is also used to treat high blood pressure (hypertension).
How should I take Lasix® (furosemide)?
Take exactly as prescribed by your doctor. Do not take more of this medication than is recommended. High doses of Lasix® may cause irreversible hearing loss. Follow the directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results.
Measure liquid medicine with a special dose-measuring spoon or medicine cup, not with a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.
Lasix® will make you urinate more often and you may get dehydrated easily. Follow your doctor’s instructions about using potassium supplements or getting enough salt and potassium in your diet.
While using Lasix®, you may need blood tests at your doctor’s office. Visit your doctor regularly.
If you are being treated for high blood pressure, keep using this medication even if you feel fine. High blood pressure often has no symptoms.
How do I store Lasix® (furosemide)?
Lasix® is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store Lasix® in the bathroom or the freezer. There may be different brands of Lasix® that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.
You should not flush Lasix® down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.
Precautions & warnings
What should I know before using Lasix® (furosemide)?
Before using this drug, tell your doctor if:
- You are pregnant or breastfeeding. This is because, while you are expecting or feeding a baby, you should only take medicines on the recommendation of a doctor.
- You are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
- You have allergy with any of active or inactive ingredients of Lasix® or other medications.
- You have any other illnesses, disorders, or medical conditions.
Tell your doctor if you have an MRI (magnetic resonance imaging) or any type of scan using a radioactive dye that is injected into your veins. Both contrast dyes and furosemide can harm your kidneys.
It is not known whether Lasix® will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medicine.
Furosemide can pass into breast milk and may harm a nursing baby. This medicine may also slow breast milk production. Tell your doctor if you are breastfeeding a baby.
Is it safe during pregnancy or breastfeeding?
There are no adequate studies in women for determining risk when using this medication during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking this medication. This medication is pregnancy risk category C, according to the US Food and Drug Administration (FDA).
FDA pregnancy risk category reference below:
- A=No risk
- B=No risk in some studies
- C=There may be some risk
- D=Positive evidence of risk
What side effects can occur from Lasix® (furosemide)?
Less serious side effects may include:
- Stomach pain
- Spinning sensation
- Mild itching or rash
Call your doctor immediately if you have:
- Ringing in your ears, hearing loss
- Itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes)
- Severe pain in your upper stomach spreading to your back
- Nausea and vomiting
- Weight loss
- Body aches
- Swelling, rapid weight gain, urinating less than usual or not at all
- Chest pain, new or worsening cough with fever, trouble breathing
- Pale skin, bruising, unusual bleeding, feeling light-headed, rapid heart rate, trouble concentrating
- Low potassium (confusion, uneven heart rate, leg discomfort, muscle weakness or limp feeling)
- Low calcium (tingly feeling around your mouth, muscle tightness or contraction, overactive reflexes)
- Headache, feeling unsteady, weak or shallow breathing
- Severe skin reaction – fever, sore throat, swelling in your face or tongue, burning in your eyes, skin pain, followed by a red or purple skin rash that spreads (especially in the face or upper body) and causes blistering and peeling
Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.
What drugs may interact with Lasix® (furosemide)?
Lasix® may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.
Taking this medicine with alcohol or with other drugs that make you sleepy can worsen this effect. Ask your doctor before taking Lasix® with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.
Lasix® can harm your kidneys. This effect is increased when you also use certain other medicines, including: antivirals, chemotherapy, injected antibiotics, medicine for bowel disorders, medicine to prevent organ transplant rejection, injectable osteoporosis medication, and some pain or arthritis medicines (including aspirin, Tylenol, Advil, and Aleve).
Tell your doctor about all your current medicines and any you start or stop using, especially:
- Chloral hydrate
- Heart or blood pressure medicine
- Ethacrynic acid
Does food or alcohol interact with Lasix® (furosemide)?
Lasix® may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.
What health conditions may interact with Lasix® (furosemide)?
Lasix® may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.
The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using this medication.
What is the dose of Lasix® (furosemide) for an adult?
The usual initial dose of Lasix® is 20 to 80 mg given as a single dose. Ordinarily a prompt diuresis ensues. If needed, the same dose can be administered 6 to 8 hours later or the dose may be increased.
The dose may be raised by 20 or 40 mg and given not sooner than 6 to 8 hours after the previous dose until the desired diuretic effect has been obtained. The individually determined single dose should then be given once or twice daily (eg, at 8 am and 2 pm). The dose of Lasix® may be carefully titrated up to 600 mg/day in patients with clinically severe edematous states.
Edema may be most efficiently and safely mobilized by giving Lasix® on 2 to 4 consecutive days each week.
When doses exceeding 80 mg/day are given for prolonged periods, careful clinical observation and laboratory monitoring are particularly advisable.
The usual initial dose of Lasix® for hypertension is 80 mg, usually divided into 40mg twice a day. Dosage should then be adjusted according to response. If response is not satisfactory, add other antihypertensive agents.
Changes in blood pressure must be carefully monitored when Lasix® is used with other antihypertensive drugs, especially during initial therapy. To prevent excessive drop in blood pressure, the dosage of other agents should be reduced by at least 50% when Lasix® is added to the regimen.
As the blood pressure falls under the potentiating effect of Lasix®, a further reduction in dosage or even discontinuation of other antihypertensive drugs may be necessary.
What is the dose of Lasix® (furosemide) for a child?
The usual initial dose of oral Lasix® in pediatric patients is 2 mg/kg body weight, given as a single dose. If the diuretic response is not satisfactory after the initial dose, dosage may be increased by 1 or 2 mg/kg no sooner than 6 to 8 hours after the previous dose.
Doses greater than 6 mg/kg body weight are not recommended. For maintenance therapy in pediatric patients, the dose should be adjusted to the minimum effective level.
The dosage has not been established in pediatric patients. It may be unsafe for your child. It is always important to fully understand the safety of the drug before using. Please consult with your doctor or pharmacist for more information.
How is Lasix® (furosemide) available?
Lasix® is available in the following dosage forms and strengths:
- Tablet: furosemide 20mg
What should I do in case of an emergency or overdose?
In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.
What should I do if I miss a dose?
If you miss a dose of Lasix®, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.
Hello Health Group does not provide medical advice, diagnosis or treatment.
Lasix. https://www.drugs.com/lasix.html. Accessed July 5, 2017
Lasix. http://www.emedicinehealth.com/drug-furosemide/article_em.htm. Accessed July 5, 2017
Lasix. http://www.webmd.com/drugs/2/drug-3776-8043/lasix-oral/furosemide-oral/details#overdose. Accessed July 5, 2017
Review Date: July 12, 2017 | Last Modified: September 13, 2019