A1,
A2,
B,
C1,
C2,
D,
E,
F,
G-H,
I-K,
L,
M,
N,
O,
P1,
P2,
Q-R,
S,
T,
U-V,
W-Z
Macrobid Side Effects, and Drug Interactions - Nitrofurantoin
Macrobid Side Effects, and Drug Interactions - Nitrofurantoin
SIDE EFFECTS
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; and chills 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.
DRUG INTERACTIONS
Antacids containing magnesium trisilicate, when administered
concomitantly with nitrofurantoin, reduce both the rate and extent of absorption.
The mechanism for this interaction probably is adsorption of nitrofurantoin
onto the surface of magnesium trisilicate.
Uricosuric drugs, such as probenecid and sulfinpyrazone, can
inhibit renal tubular secretion of nitrofurantoin. The resulting increase in
nitrofurantoin serum levels may increase toxicity, and the decreased urinary
levels could lessen its efficacy as a urinary tract antibacterial.
Drug/Laboratory Test Interactions
As a result of the presence of nitrofurantoin, a false-positive
reaction for glucose in the urine may occur. This has been observed with Benedict’s
and Fehling’s solutions but not with the glucose enzymatic test.
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