Macrobid

Macrobid is part of the drug class:

• Nitrofuran derivatives

Serious side effects have been reported with Macrobid including the following:

• Lung problems (pulmonary hypersensitivity reactions). Tell your healthcare provider right away if you have some or all of the following symptoms:
  • malaise
  • dyspnea
  • cough
• Liver problems
• Peripheral neuropathy (nerve problems)
• Clostridium difficile- associated diarrhea

Macrobid can cause drowsiness. Do not drive or operate heavy machinery until you know how Macrobid affects you.

Do not take Macrobid if you:

• are known hypersensitivity/allergy to Macrobid or to any of its ingredients
• significant impairment of renal function
• pregnant patients at term (38-42 weeks gestation) as well as during labor and delivery
• in patients with a previous history of cholestatic jaundice/hepatic dysfunction associated with Macrobid

Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The dose your doctor recommends may be based on the following:

• the condition being treated
• other medical conditions you have
• other medications you are taking
• how you respond to this medication
• your age

The recommended dose of Macrobid for the treatment of urinary tract infection is 100 mg every 12 hours.

Nitrofurantoin is an antibiotic that fights bacteria in the body.

Nitrofurantoin is used to treat urinary tract infections.

Nitrofurantoin may also be used for purposes not listed in this medication guide.

• It is used to treat or prevent a bladder infection.

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Signs of a pancreas problem (pancreatitis) like very bad stomach pain, very bad back pain, or very bad upset stomach or throwing up.
• Change in eyesight.
• Eye pain.
• Not able to control eye movements.
• Feeling confused.
• Very bad headache.
• Low mood (depression).
• Change in color of skin to a bluish color like on the lips, nail beds, fingers, or toes.
• Feeling very tired or weak.
• It is common to have diarrhea when taking this medicine. Rarely, a very bad form of diarrhea called Clostridium difficile (C diff)–associated diarrhea (CDAD) may occur. Sometimes, this has led to a deadly bowel problem (colitis). CDAD may happen while you are taking Macrobid or within a few months after you stop taking it. Call your doctor right away if you have stomach pain or cramps, very loose or watery stools, or bloody stools. Do not try to treat loose stools without first checking with your doctor.

• Store at room temperature.
• Store in a dry place. Do not store in a bathroom.
• Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
• Check with your pharmacist about how to throw out unused drugs.

Nitrofurantoin is an antibacterial agent specific for urinary tract infections. The Macrobid® brand of nitrofurantoin is a hard gelatin capsule shell containing the equivalent of 100 mg of nitrofurantoin in the form of 25 mg of nitrofurantoin macrocrystals and 75 mg of nitrofurantoin monohydrate.

The chemical name of nitrofurantoin macrocrystals is 1-[[[5-nitro-2-furanyl]methylene]amino]-2,4-imidazolidinedione. The chemical structure is the following:

Molecular Weight: 238.16

The chemical name of nitrofurantoin monohydrate is 1-[[[5-nitro-2-furanyl]methylene]amino]-2,4- imidazolidinedione monohydrate. The chemical structure is the following:

Molecular Weight: 256.17

Inactive Ingredients: Each capsule contains carbomer 934P, corn starch, compressible sugar, D&C Yellow No. 10, edible gray ink, FD&C Blue No. 1, FD&C Red No. 40, gelatin, lactose, magnesium stearate, povidone, talc, and titanium dioxide.

Anuria, oliguria, or significant impairment of renal function (creatinine clearance under 60 mL per minute or clinically significant elevated serum creatinine) are contraindications. Treatment of this type of patient carries an increased risk of toxicity because of impaired excretion of the drug.

Because of the possibility of hemolytic anemia due to immature erythrocyte enzyme systems (glutathione instability), the drug is contraindicated in pregnant patients at term (38-42 weeks gestation), during labor and delivery, or when the onset of labor is imminent. For the same reason, the drug is contraindicated in neonates under one month of age.

Macrobid is contraindicated in patients with a previous history of cholestatic jaundice/hepatic dysfunction associated with nitrofurantoin.

Macrobid is also contraindicated in those patients with known hypersensitivity to nitrofurantoin.

In clinical trials of Macrobid, the most frequent clinical adverse events that were reported as possibly or probably drug-related were nausea (8%), headache (6%), and flatulence (1.5%). Additional clinical adverse events reported as possibly or probably drug-related occurred in less than 1% of patients studied and are listed below within each body system in order of decreasing frequency:

Gastrointestinal: Diarrhea, dyspepsia, abdominal pain, constipation, emesis

Neurologic: Dizziness, drowsiness, amblyopia

Respiratory: Acute pulmonary hypersensitivity reaction (see WARNINGS)

Allergic: Pruritus, urticaria

Dermatologic: Alopecia

Miscellaneous: Fever, chills, malaise

The following additional clinical adverse events have been reported with the use of nitrofurantoin:

Gastrointestinal: Sialadenitis, pancreatitis. There have been sporadic reports of pseudomembranous colitis with the use of nitrofurantoin. The onset of pseudomembranous colitis symptoms may occur during or after antimicrobial treatment. (See WARNINGS.)

Neurologic: Peripheral neuropathy, which may become severe or irreversible, has occurred. Fatalities have been reported. Conditions such as renal impairment (creatinine clearance under 60 mL per minute or clinically significant elevated serum creatinine), anemia, diabetes mellitus, electrolyte imbalance, vitamin B deficiency, and debilitating diseases may increase the possibility of peripheral neuropathy. (See WARNINGS.)

Asthenia, vertigo, and nystagmus also have been reported with the use of nitrofurantoin.

Benign intracranial hypertension (pseudotumor cerebri), confusion, depression, optic neuritis, and psychotic reactions have been reported rarely. Bulging fontanels, as a sign of benign intracranial hypertension in infants, have been reported rarely.

Respiratory:

CHRONIC, SUBACUTE, OR ACUTE PULMONARY HYPERSENSITIVITY REACTIONS MAY OCCUR WITH THE USE OF NITROFURANTOIN.

CHRONIC PULMONARY REACTIONS GENERALLY OCCUR IN PATIENTS WHO HAVE RECEIVED CONTINUOUS TREATMENT FOR SIX MONTHS OR LONGER. MALAISE, DYSPNEA ON EXERTION, COUGH, AND ALTERED PULMONARY FUNCTION ARE COMMON MANIFESTATIONS WHICH CAN OCCUR INSIDIOUSLY. RADIOLOGIC AND HISTOLOGIC FINDINGS OF DIFFUSE INTERSTITIAL PNEUMONITIS OR FIBROSIS, OR BOTH, ARE ALSO COMMON MANIFESTATIONS OF THE CHRONIC PULMONARY REACTION. FEVER IS RARELY PROMINENT.

THE SEVERITY OF CHRONIC PULMONARY REACTIONS AND THEIR DEGREE OF RESOLUTION APPEAR TO BE RELATED TO THE DURATION OF THERAPY AFTER THE FIRST CLINICAL SIGNS APPEAR. PULMONARY FUNCTION MAY BE IMPAIRED PERMANENTLY, EVEN AFTER CESSATION OF THERAPY. THE RISK IS GREATER WHEN CHRONIC PULMONARY REACTIONS ARE NOT RECOGNIZED EARLY.

In subacute pulmonary reactions, fever and eosinophilia occur less often than in the acute form. Upon cessation of therapy, recovery may require several months. If the symptoms are not recognized as being drug-related and nitrofurantoin therapy is not stopped, the symptoms may become more severe.

Acute pulmonary reactions are commonly manifested by fever, chills, cough, chest pain, dyspnea, pulmonary infiltration with consolidation or pleural effusion on x-ray, and eosinophilia. Acute reactions usually occur within the first week of treatment and are reversible with cessation of therapy. Resolution often is dramatic. (See WARNINGS.)

Changes in EKG (e.g., non-specific ST/T wave changes, bundle branch block) have been reported in association with pulmonary reactions.

Cyanosis has been reported rarely.

Hepatic: Hepatic reactions, including hepatitis, cholestatic jaundice, chronic active hepatitis, and hepatic necrosis, occur rarely. (See WARNINGS.)

Allergic: Lupus-like syndrome associated with pulmonary reaction to nitrofurantoin has been reported. Also, angioedema; maculopapular, erythematous, or eczematous eruptions; anaphylaxis; arthralgia; myalgia; drug fever; chills; and vasculitis (sometimes associated with pulmonary reactions) have been reported. Hypersensitivity reactions represent the most frequent spontaneously-reported adverse events in worldwide postmarketing experience with nitrofurantoin formulations.

Dermatologic: Exfoliative dermatitis and erythema multiforme (including Stevens-Johnson syndrome) have been reported rarely.

Hematologic: Cyanosis secondary to methemoglobinemia has been reported rarely.

Miscellaneous: As with other antimicrobial agents, superinfections caused by resistant organisms, e.g., Pseudomonas species or Candida species, can occur.

In clinical trials of Macrobid, the most frequent laboratory adverse events (1-5%), without regard to drug relationship, were as follows: eosinophilia, increased AST (SGOT), increased ALT (SGPT), decreased hemoglobin, increased serum phosphorus. The following laboratory adverse events also have been reported with the use of nitrofurantoin: glucose-6-phosphate dehydrogenase deficiency anemia (see WARNINGS), agranulocytosis, leukopenia, granulocytopenia, hemolytic anemia, thrombocytopenia, megaloblastic anemia. In most cases, these hematologic abnormalities resolved following cessation of therapy. Aplastic anemia has been reported rarely.

1. Clinical and Laboratory Standards Institute. Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria That Grow Aerobically; Approved Standard-Eighth Edition. CLSI document M07-A8 [ISBN 1-56238-689-1]. Clinical and Laboratory Standards Institute, 940 West Valley Road, Suite 1400, Wayne, Pennsylvania 19087-1898 USA, 2009.
2. Clinical and Laboratory Standards Institute.  Performance Standards for Antimicrobial Disk Susceptibility Tests; Approved Standard- Tenth Edition. CLSI document M02-A 10 [ISBN 1-56238-688-3]. Clinical and Laboratory Standards Institute, 940 West Valley Road, Suite 1400, Wayne, Pennsylvania 19087-1898 USA, 2009.
3. Clinical and Laboratory Standards Institute. Performance Standards for Antimicrobial Susceptibility Testing; Nineteenth Informational Supplement. CLSI document M100-S19 [ISBN 1-56238-716-2]. Clinical and Laboratory Standards Institute, 940 West Valley Road, Suite 1400, Wayne, Pennsylvania 19087-1898 USA, 2010.

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

Applies to nitrofurantoin: oral capsule, oral suspension, oral tablet

Along with its needed effects, nitrofurantoin (the active ingredient contained in Macrobid) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking nitrofurantoin:

• Changes in facial skin color
• chest pain
• chills
• cough
• fever
• general feeling of discomfort or illness
• hives
• hoarseness
• itching
• joint or muscle pain
• shortness of breath
• skin rash
• sudden trouble in swallowing or breathing
• swelling of the face, mouth, hands, or feet
• troubled breathing

• Black, tarry stools
• blood in the urine or stools
• burning, numbness, tingling, or painful sensations
• dizziness
• drowsiness
• headache
• pinpoint red spots on the skin
• sore throat
• unsteadiness or awkwardness
• unusual bleeding or bruising
• unusual tiredness or weakness
• weakness in the arms, hands, legs, or feet

• Abdominal or stomach pain
• blindness
• blistering, peeling, or loosening of the skin and mucous membranes
• blue-yellow color blindness
• bluish color of the fingernails, lips, skin, palms, or nail beds
• blurred vision or loss of vision, with or without eye pain
• bulging soft spot on the head of an infant
• change in the ability to see colors, especially blue or yellow
• confusion
• cracks in the skin
• darkening of the urine
• decreased vision
• diarrhea
• diarrhea, watery and severe, which may also be bloody
• eye pain
• general tiredness and weakness
• light-colored stools
• loss of appetite
• loss of heat from the body
• mental depression
• mood or mental changes
• nausea or vomiting
• pale skin
• pale stools
• red skin lesions, often with a purple center
• red, irritated eyes
• red, swollen skin
• red, thickened, or scaly skin
• skin rash
• sores, ulcers, or white spots on the lips or in the mouth
• swollen or painful glands
• tenderness of salivary glands
• unpleasant breath odor
• upper right abdominal pain
• visual changes
• vomiting of blood
• wheezing or tightness in the chest
• yellow eyes or skin

Some side effects of nitrofurantoin may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

• Diarrhea
• gas

• Dizziness or lightheadedness
• feeling of constant movement of self or surroundings
• lack or loss of strength
• loss of hair, temporary
• sensation of spinning
• uncontrolled eye movements

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.