Furosemide Side Effects

Furosemide side effects: the trade name for furosemide is Lasix (See Lasix side effects). Furosemide is available in 20 mg 40 mg and 80 mg tablets, as an oral liquid and as in fusible IV and IM solutions. Furosemide is a very fast acting and very potent diuretic in the class of diuretics called loop diuretics. The brand name for furosemide, Lasix, was chosen because furosemide tends to work very quickly and its affect lasts about six hours therefore Lasix implying lasts six hours. Furosemide has FDA indications for diuresis for congestive heart failure and pulmonary edema, other types of edema, and for high blood pressure associated with reduced renal function. Of the furosemide side effects many are related directly to the potent and very rapid diuresis that furosemide causes. When the patient takes furosemide they often notice a very rapid increase in urine output lead them to want to stay near a toilet for the several hours after each dose of furosemide is taken.

Black box warnings: the very rapid diuresis caused by furosemide can cause critical imbalances of fluids and electrolytes. Each individual’s dose needs to be tailored to their own needs and close supervision by their physician is warranted.

Common Furosemide Side Effects: the majority of patients prescribed furosemide will note a dramatic increase in urine output for a few hours after the doses taken. When significant fluid overload or edema is present in patients with normal renal function this can be very dramatic. This rapid diuresis can cause major fluid and electrolyte shifts which can cause muscle cramping, as well as what is often described by patients as kidney pain when the experience pain in their flanks. Most of the common furosemide side effects are directly related to the way furosemide works as a diuretic, that being inhibition of the reabsorption of chloride in the part of the kidney called the loop of Henly. As the anion on chloride is excreted in the urine Ions are lost along with the chloride. In addition to the intended loss of cation sodium significant loss of potassium calcium and magnesium can occur leading to hypokalemia hypocalcemia and hypomagnesimia. This rapid loss of fluid and electrolytes can also cause low blood pressure particularly orthostatic hypotension. Orthostatic hypotension is a major drop in blood pressure when moving from a lying to a sitting or standing position. Additional common furosemide side effects include muscle cramps, abdominal cramps, weakness, and Pierce Ephesians. Skin rash, itching, and photosensitivity are also commonly seen. Elevated triglyceride cholesterol are among the lipid changes seen as furosemide side effects. Loss of appetite blurry vision and elevation of serum transaminase levels can also be seen as common furosemide side effects.

Serious Furosemide Side Effects: the manufacturers list of serious furosemide side effects is extensive and the reader should consult the prescriber’s information by the manufacturer for complete list of furosemide side effects. Metabolic abnormalities like severe hypokalemia, metabolic alkalosis, low blood pressure associated with severe volume depletion, and other electrolyte imbalances can be serious furosemide side effects. Bone marrow disorders that can include thrombocytopenia, hemolytic anemia, agranulocytosis, eosinophilia, leukopenia, and aplastic anemia have been reported as serious furosemide side effects. Dermatologic disorders that can be serious furosemide side effects include Stevens-Johnson syndrome, toxic epidermal necrolysis, and exfoliative dermatitis. Vascular side effects like vasculitis and thrombosis as well as interstitial nephritis cholestatic jaundice exacerbation of systemic lupus erythematosus and pancreatitis are other serious furosemide side effects.

Unusual Furosemide Side Effects: tinnitus as a manifestation of ototoxicity is an unusual furosemide side effects. Otherwise furosemide side effects tend to be predictable or relatively uncommon.

Drug Interactions: use of furosemide in combination with lithium or aminoglycosides should be avoided. The list of medications with need for careful monitoring when used with furosemide is extensive and this segment will include only a few of the more commonly used medications where furosemide side effects are noted. The ace inhibitors and ARB’s, most medications that can cause renal toxicity like acetaminophen, aspirin and the rest of the nonsteroidal anti-inflammatory medication class as well as other diuretics require careful monitoring. Refer to the prescribing information by the manufacturer for a complete list of medications where use in combination with furosemide can have adverse effects.

Pregnancy and Lactation: furosemide is pregnancy category C, but differences in the different trimesters of pregnancy have been noted. The safety of furosemide in lactation is not known.

Special Considerations Regarding Furosemide: The use of furosemide is very important in many serious medical conditions including congestive heart failure and pulmonary edema as well as other causes of fluid retention. The very rapid onset of action and the potent diuresis obtained with furosemide as well as the many furosemide side effects seen make furosemide one of the commonly used medications where a good understanding of furosemide side effects is very important.