Lithostat helps prevent a build-up of ammonia in urine that can be caused by a bladder infection. Increased ammonia in urine can cause the growth of kidney stones.

Lithostat is used to keep urine ammonia levels low in people who have a certain type of chronic bladder infection.

Lithostat is not an antibiotic and will not treat the infection itself. Lithostat is only part of a treatment program that may also include antibiotics to treat the infection, and surgery to remove kidney stones. Follow your doctor's instructions very closely.

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

You should not use Lithostat if you have kidney disease, or if you have bladder symptoms that have not been checked by a doctor.

Lithostat can harm an unborn baby or cause birth defects. Do not use Lithostat if you are pregnant or if you are not using birth control.

Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take Lithostat in larger or smaller amounts or for longer than recommended.

Take Lithostat on an empty stomach, at least 1 hour before or 2 hours after a meal.

This medicine is usually taken every 6 to 8 hours. Follow your doctor's instructions.

Do not share this medicine with another person, even if they have the same symptoms you have. Lithostat is for use only in people with a certain type of bladder infection.

While using Lithostat, you may need frequent blood and urine tests.

Take this medication for the full prescribed length of time, even if you have no symptoms of a bladder infection. Lithostat is not an antibiotic and will not treat a bacterial infection alone. Take your antibiotic medication as directed.

You may need to use Lithostat for several years.

Store at room temperature away from moisture and heat. Keep the bottle tightly closed when not in use.

You should not use Lithostat if you are allergic to it, or if you have:

• kidney disease;

• bladder symptoms that have not been checked by a doctor with lab tests; or

• if you are pregnant or are not using birth control.

To make sure Lithostat is safe for you, tell your doctor if you have:

• liver disease;

• hemolytic anemia (a lack of red blood cells); or

• a weak immune system.

FDA pregnancy category X. This medicine can harm an unborn baby or cause birth defects. Do not use Lithostat if you are pregnant. Use effective birth control to prevent pregnancy while taking this medicine. Tell your doctor right away if you become pregnant or if you stop using birth control for any reason during treatment with this medicine.

It is not known whether acetohydroxamic acid passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.

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.

Remember to take Lithostat on an empty stomach.

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

Overdose symptoms may include general ill feeling, vomiting, and feeling anxious or uneasy.

You may have a skin rash or flushing (warmth, redness, or tingly feeling) if you drink alcohol while taking Lithostat.

Ask your doctor before taking any vitamin or mineral supplement that contains iron.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Lithostat may cause serious side effects. Call your doctor at once if you have:

• pounding heartbeats or fluttering in your chest;

• signs of a blood clot in your leg--pain, swelling, warmth, or redness in one or both legs; or

• signs of a red blood cell disorder--pale or yellowed skin, dark colored urine, fever, confusion or weakness.

Common side effects of Lithostat may include:

• headache during the first 2 days of treatment;

• skin rash, warmth, tingling or redness (especially if you drink alcohol while taking Lithostat);

• upset stomach, nausea, loss of appetite;

• depressed mood;

• anxiety, tremors, nervousness; or

• 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.

Other drugs may interact with acetohydroxamic acid, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.