Tiopronin (Oral)

Tiopronin is a thiol medication, prescribed by a doctor, used to prevent kidney stones in patients who experience severe cystinuria. The drug works by improving the way cystine dissolves in urine.


Tiopronin is a tablet taken orally typically prescribed for patients who are prone to kidney stones. Specifically, this drug is used by patients who have an excessive amount of cystine in the urine (cystinuria), producing a concentration of more than 500 mg per day. This condition is typically inherited, and Tiopronin treats it by improving how cystine dissolves in the patient's urine.

Tiopronin is usually only prescribed after other methods, such a change of diet (restricting sodium use) or increasing water or fluid intake, have proven unsuccessful in preventing kidney stones. It is also typically prescribed to patients who are unable to take other medications for cystinuria. Since the severity of cystinuria can range, the length of time this drug is prescribed to a patient can range from short-term to long term. In addition to taking the medication, a doctor may encourage the patient to continue with the aforementioned lifestyle changes in order to receive the most benefit from treatment.

Although Tiopronin is helpful for treating kidney stones, the side effects of the drugs can be very serious. It's important to fully discuss the use of this drug with your healthcare professional.

On rare occasions, Tiopronin is sometimes also prescribed as part of a treatment for Wilson's disease. In that situation, it's used to bind metal nanoparticles when there is an oversupply of copper throughout the body. In addition, it has been researched in usage for treating arthritis, as well as treatment in the occurrence of aneurysmal subarachnoid hemorrhage.

Conditions treated

  • The prevention of kidney stones

Type of Medicine

  • Thiol

Side Effects

In addition to preventing kidney stones, Tiopronin may cause some unwanted side effects to the body. The most common side effects of taking this drug as prescribed include:

  • Abdominal/stomach pain
  • Gas and bloating
  • Soft stools or diarrhea
  • Loss of appetite
  • Nausea
  • Vomiting
  • Skin abnormalities such as warts, wrinkling, peeling, and dryness of the skin.

A less common side effect is a change in the patient's taste or smell.

These more typical side effects tend to go away as patients become used to the medication. If the aforementioned side effects tend to become bothersome or do not go away with time, it's important to discuss your concerns with your healthcare professional. Your physician may be able to answer additional questions you have or help you reduce the appearance of these symptoms.

Tiopronin can cause more severe side effects that may warrant the immediate need to have a discussion with your doctor. These include:

  • Yellowing of the skin or the eyes
  • Muscle pain
  • Sore throat
  • Fever
  • Unusual bleeding or bruising.

In addition, if you experience pain, swelling, or tenderness of the skin, a skin rash, hives, or itching, or ulcers and sores in the mouth, it's important to consult your physician as soon as possible. Some more rare severe side effects could also include bloody/cloudy urine, chills, difficulty breathing, high blood pressure, hoarseness, joint pain, swelling feet/lower legs, tenderness and unusual bleeding.


Tiopronin is typically taken on an empty stomach, at least thirty minutes before a meal or at least two hours afterward. It's also important to consume two full 8-ounce glasses of water with each meal, before bedtime, and during the night.

As with any drug prescribed by your doctor, it is imperative to take Tiopronin as directed. This includes any special instructions given by your physician, such as a diet that restricts the consumption of methionine (found in milk, eggs, cheese, fish, and other animal proteins). It's also important your doctor knows if you follow any other special diet, including a low-sodium or low-sugar diet.

Do not stop taking this medicine without consulting your doctor first, as a sudden stopping and starting of this medicine could increase the possibility of unwanted side effects.

The dosage of this drug will vary for different patients. Follow the instructions written on the prescription bottle. The information provided here represents the average dosage taken by the typical patient. If your dosage should be different, it's important to follow the instructions as outlined by your doctor and on your medication bottle.

The strength of your medication also varies from patient to patient, and it may determine how many doses are taken each day, the time between each dose taken, and the amount taken with each dose.

The typical Tiopronin usage in oral form to prevent kidney stones is 800 milligrams (mg) a day, divided into three doses for adults. For children 9 years of age and older, amount of medicine is determined by body weight and will typically start at 15 mg per kilogram (kg) (6.8 mg per pound) of body weight a day, divided into three doses. For children less than 9, a doctor will determine the dosage to take. As always, dosage may change during treatment or as needed, as determined by your doctor.

The length of time the patient takes this medication will also be determined by a doctor, as it can range from a short-term solution to a long-term treatment. It's important to discuss this with your doctor.

Drug Interactions

There are currently no known drug interactions for Tiopronin, however, this does not mean that interactions do not exist that could be serious or could potentially exasperate any side effects. Your physician, pharmacist, or other healthcare provider should be able to inform you about any potential side effects with other prescriptions you may be taking. They should also be able to monitor and alert you to any possible interactions. It's important to discuss any medication you may be taking with your health care professional, and inform them of any changes to your regimen.


Your diet could affect the usage of this medication. It's important to discuss your diet with your doctor before taking this medication, as well as discuss any potential interactions with alcohol or tobacco.

Pregnancy & Breastfeeding

There are no adequate studies to show a potential risk to pregnant women, or a risk to an infant while breastfeeding. However, it's important to discuss any potential risk with your doctor and discuss any questions you may have.


When discussing your new Tiopronin prescription with your doctor, let your doctor or pharmacist know if you have had an allergic reaction to this medication in the past or have had any severe side effects from usage. It's also important to inform your doctor of allergies, as the inactive ingredients in Tiopronin can cause various allergic reactions or side effects. It's important to always make your doctor or pharmacist aware of your medical history, including blood disorders, liver disease, and kidney disease.

Prior to beginning your prescription of Tiopronin, it's important to let your healthcare professional know if you have any allergies to this medication or have experienced severe side effects in the past. The inactive ingredients in the medication could initiate an allergic reaction or other health issues. Discussing with your pharmacist will give you more information. It's also important to discuss your medical history with your doctor, including any blood disorders you may have experienced in the past, such as anemia, low platelet count, kidney disease, or liver disease.

If a patient has overdosed on Tiopronin and is experiencing trouble breathing or loss of consciousness, it's important to seek medical help right away. You can also seek help from your local poison control center who can better assist you in the event of an overdose.


This medication is best stored at a room temperature, around 77 degrees Fahrenheit, or 25 degrees Celsius. Keep away from direct light or moisture. If necessary, it is possible to briefly store this medicine in a temperature between 59 and 86 degrees.

Medication should be properly destroyed if outdated or no longer needed. Do not flush or pour the medication down the drain unless advised to. Otherwise, always properly destroy the medication. For details on safe disposal, consult a pharmacist.

Keep this medication, as well as other prescription medication, away from children and animals.


Tiopronin is a tablet taken orally prescribed to patients who are prone to kidney stones. The drug works by preventing kidney stones by reducing the amount of cystine in their urine (cystinuria). Cystinuria is typically inherited condition where a patient produces an excess of cystine, which can lead to kidney stones. Patients who take this drug typically has a daily cystine concentration of over 500 mg per day. By using Tiopronin, a patient can reduce the likelihood of kidney stones and thus the need for kidney stone treatment. Typically, Tiopronin is only prescribed after non-medical treatment, such as a change in diet, or if other medical treatments attempted are not successful. Tiopronin may also rarely be prescribed to treat Wilson's disease, as it can help combat an oversupply of copper in the body.

While taking Tiopronin, it's important for the patient to pay close attention to side effects. It could cause rare but very serious side effects that need to be monitored closely or treated immediately by a physician. This can include yellowing of the skin, unusual bleeding, and breathing issues. Less severe and less common side effects could appear during treatment, but may eventually dissipate as treatment continues. The patient's physician could choose to alter treatment as time goes on, depending on whether or not the intended outcome has been accomplished.

Last Reviewed:
December 24, 2017
Last Updated:
April 05, 2018
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