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Generic name: acetohydroxamic acida-SEET-oh-HYE-drox-AM-ik-AS-id ]
Drug class: Miscellaneous genitourinary tract agents

Medically reviewed by on Aug 31, 2022. Written by Cerner Multum.

What is Lithostat?

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.

This medicine 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.

Before taking this medicine

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:

FDA pregnancy category X. Lithostat 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.

How should I take Lithostat?

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 this medicine 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.

What happens if I miss a dose?

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.

What happens if I overdose?

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.

What should I avoid while taking Lithostat?

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.

Lithostat side effects

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:

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.

What other drugs will affect Lithostat?

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.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.