Acetohydroxamic acid

Name: Acetohydroxamic acid

What is acetohydroxamic acid?

Acetohydroxamic acid 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.

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

Acetohydroxamic acid is not an antibiotic and will not treat the infection itself. This medicine 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.

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

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 acetohydroxamic acid 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 do I need to tell my doctor BEFORE I take Acetohydroxamic Acid?

  • If you have an allergy to acetohydroxamic acid or any other part of acetohydroxamic acid.
  • If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
  • If you have a bladder infection that can be treated by other drugs or surgery.
  • If you have kidney disease.
  • If you are pregnant or may be pregnant. Do not take this medicine if you are pregnant.
  • If you are able to get pregnant and are not using birth control.
  • If you are breast-feeding or plan to breast-feed.

This is not a list of all drugs or health problems that interact with acetohydroxamic acid.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this medicine with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

How is this medicine (Acetohydroxamic Acid) best taken?

Use this medicine as ordered by your doctor. Read all information given to you. Follow all instructions closely.

  • Take on an empty stomach. Take 1 hour before or 2 hours after meals.
  • Do not take iron, multivitamins, or other products that contain iron with acetohydroxamic acid.
  • To gain the most benefit, do not miss doses.
  • Keep taking this medicine as you have been told by your doctor or other health care provider, even if you feel well.

What do I do if I miss a dose?

  • Take a missed dose as soon as you think about it.
  • If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
  • Do not take 2 doses at the same time or extra doses.

Acetohydroxamic Acid Drug Class

Acetohydroxamic Acid is part of the drug class:

  • Other urologicals

Acetohydroxamic Acid and Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Acetohydroxamic Acid falls into category X:

It has been shown that women taking Acetohydroxamic Acid during pregnancy may have babies with problems. There are no situations where the benefits of the medication for the mother outweigh the risks of harm to the baby. These medicines should never be used by pregnant women.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • Chest pain or pressure.
  • Swelling, warmth, numbness, change of color, or pain in a leg or arm.
  • A heartbeat that does not feel normal.
  • Dark urine or yellow skin or eyes.
  • Feeling very tired or weak.
  • Very upset stomach or throwing up.
  • Low mood (depression).

For Healthcare Professionals

Applies to acetohydroxamic acid: oral tablet


Gastrointestinal side effects including nausea, vomiting, anorexia, and malaise have been reported in 20% to 25% of patients.[Ref]

In most patients the symptoms were mild, transitory, and did not result in interruption of treatment.[Ref]


In most patients the symptoms were mild and transitory, but in about 6% of patients the symptoms were sufficiently distressing to warrant interruption or discontinuation of treatment.[Ref]

Psychiatric side effects including depression, anxiety, nervousness, and tremulousness have been observed in approximately 20% of patients.[Ref]


Hematologic side effects including hemolytic anemia (15%) have been reported. Approximately 3% of patients developed a hemolytic anemia of sufficient magnitude to warrant interruption in treatment. A mild reticulocytosis (5% to 6%) without anemia, has also been reported.[Ref]

The laboratory findings are occasionally accompanied by systemic symptoms such as malaise, lethargy and fatigue, and gastrointestinal symptoms. Symptoms and laboratory findings have invariably improved following cessation of treatment with acetohydroxamic acid. The hematological abnormalities are more prevalent in patients with advanced renal failure.[Ref]

Nervous system

These headaches are mild, responsive to oral salicylate-type analgesics, and usually disappear spontaneously. The headaches have not been associated with vertigo, tinnitus, or visual or auditory abnormalities.[Ref]

Nervous system side effects have included mild headaches during the first 48 hours of treatment. Tremulousness and nervousness have also been reported.[Ref]


The macular skin rash has usually occurred when acetohydroxamic acid has been taken concomitantly with alcoholic beverages, but in a few patients in the absence of alcohol consumption. The rash commonly appeared 30 to 45 minutes after ingestion of alcoholic beverages; it characteristically disappeared spontaneously in 30 to 60 minutes. The rash may be associated with a general sensation of warmth. In some patients the rash is sufficiently severe to warrant discontinuation of treatment, but most patients have continued treatment, avoiding alcohol or using smaller quantities of it.[Ref]

A macular skin rash has occurred in the upper extremities and on the face of several patients taking acetohydroxamic acid on a long-term basis. Alopecia has also been reported.[Ref]


Several of the affected patients had phlebitic episodes prior to treatment.

The patient with phlebothrombosis had an associated traumatic injury to the groin. It is unclear whether the phlebitis was related to or exacerbated by treatment with acetohydroxamic acid. No patient in the three year controlled (Phase III) clinical trial developed phlebitis. In all instances these vascular abnormalities returned to normal following appropriate medical therapy.

The phlebitis and emboli resolved following discontinuation of acetohydroxamic acid and implementation of appropriate medical therapy. Several patients have resumed treatment with acetohydroxamic acid without ill effect.[Ref]

Cardiovascular side effects including superficial phlebitis involving the lower extremities has been reported in several patients on acetohydroxamic acid during clinical trials. Palpitations have also been reported. Embolic phenomena have been reported in three patients taking acetohydroxamic acid in the Phase II trial. One patient developed deep vein thrombosis of the lower extremities.[Ref]

Some side effects of acetohydroxamic acid may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Usual Adult Dose for Urinary Tract Infection

Starting dose: 12 mg/kg/day administered at 6 to 8 hour intervals at a time when the stomach is empty.

Then progress to one tablet orally 3 to 4 times a day in a total daily dose of 10 to 15 mg/kg/day.

The maximum daily dose should be no more than 1.5 grams, regardless of body weight.