Nitrofurantoin is an antibiotic that is used to treat urinary tract infections caused by bacteria.

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

You should not take nitrofurantoin if you are allergic to it, or if you have:

• severe kidney disease;
• urination problems (little or no urination); or
• a history of jaundice or liver problems caused by taking nitrofurantoin.

Do not take nitrofurantoin during late pregnancy (from 38 weeks through delivery).

Tell your doctor if you have ever had:

• kidney disease;
• anemia;
• diabetes;
• an electrolyte imbalance or vitamin B deficiency;
• glucose-6-phosphate dehydrogenase (G6PD) deficiency; or
• any type of debilitating disease.

You should not breastfeed a baby younger than 1 month old while you are taking nitrofurantoin.

Nitrofurantoin should not be given to a child younger than 1 month old.

Use Nitro Macro (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Call your doctor at once if you have:

• severe stomach pain, diarrhea that is watery or bloody (even if it occurs months after your last dose);
• vision problems;
• fever, chills, cough, chest pain, trouble breathing;
• numbness, tingling, or burning pain in your hands or feet;
• severe pain behind your eyes;
• pale skin, weakness;
• joint pain or swelling with fever, swollen glands, and muscle aches;
• pain, redness, or swelling in your lower jaw;
• increased pressure inside the skull--severe headaches, ringing in your ears, dizziness, nausea, vision problems, pain behind your eyes; or
• signs of liver or pancreas problems--upper stomach pain (that may spread to your back), nausea or vomiting, dark urine, yellowing of the skin or eyes.

Side effects may be more likely in older adults.

Common side effects may include:

• headache, dizziness, drowsiness, weakness;
• gas, indigestion, loss of appetite;
• nausea, vomiting;
• muscle or joint pain;
• rash, itching; or
• temporary hair loss.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, call your doctor before using anti-diarrhea medicine.

Avoid taking an antacid that contains magnesium trisilicate, which could make it harder for your body to absorb nitrofurantoin.