What is the dosage for nitrofurantoin (Macrobid, Macrodantin, Furadantin)?
- The recommended adult dose for treating urinary tract infections is 50-100 mg 4 times daily (Macrodantin, Furadantin) or 100 mg every 12 hours (Macrobid) for 7 days or for 3 days after obtaining sterile urine.
- Nitrofurantoin can be taken with or without meals. Taking it with meals increases its absorption into the body.
- The suspension can be mixed with water, milk, juice, or infant formula.
- It also is used once a day (or in some children, twice daily) to prevent urinary tract infections.
- It should not be used in persons with poor kidney function.
Which drugs or supplements interact with nitrofurantoin (Macrobid, Macrodantin, Furadantin)?
- High doses of probenecid (Benemid) or sulfinpyrazone (Anturane) can partially block the kidneys' elimination of nitrofurantoin. This can increase the blood concentrations of nitrofurantoin and the risk of toxicity from nitrofurantoin.
- Concomitant administration of a magnesium trisilicate antacid may decrease the absorption of nitrofurantoin, reducing the effectiveness of nitrofurantoin.
- Nitrofurantoin may reduce the activity of live tuberculosis vaccine (BCG vaccine) and live typhoid vaccine. In laboratory tests, nitrofurantoin reduced the effect of quinolone antibiotics, for example, norfloxacin (Noroxin). Therefore, nitrofurantoin should not be combined with quinolone antibiotics.
Is nitrofurantoin (Macrobid, Macrodantin, Furadantin) safe to use during pregnancy or while breastfeeding?
- Although there are no adequate studies of nitrofurantoin in pregnant women, many women have safely used it during pregnancy. However, nitrofurantoin should not be used near the time of delivery (38-42 weeks gestation) since it interferes with the immature enzyme systems in the red blood cells of newborns, damaging the cells and resulting in anemia.
- Nitrofurantoin is distributed into breast milk and should be used with caution in women who are breastfeeding.
What else should I know about nitrofurantoin (Macrobid, Macrodantin, Furadantin)?
What preparations of nitrofurantoin (Macrobid, Macrodantin, Furadantin) are available?
- Capsules: 25, 50, 75, and 100 mg.
- Oral suspension: 25 mg/5 ml.
How should I keep nitrofurantoin (Macrobid, Macrodantin, Furadantin) stored?
- All formulations should be kept at room temperature, 15 C TO 30 C (59 F to 86 F).
When was nitrofurantoin (Macrobid, Macrodantin, Furadantin) approved by the FDA?
- The FDA approved nitrofurantoin in 1953.
Reference: FDA Prescribing Information
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