Nitisinone (Oral)

Overview

Patients who suffer from a hereditary condition that results in too much tyrosine in their blood have found relief by taking the prescription drug known as nitisinone. Tyrosinemia type 1 is not curable with this medication, but its use can help to slow the debilitating effects of the disease. The effective treatment of tyrosinemia type 1 will also require significant changes to the patients' diet as well as other lifestyle habits.

Nitisinone can temporarily reduce the level of platelets and white blood cells that are contained in the patient's system, thus increasing their risk for infection and complications relating to bleeding and bruising. Patients should do all that they can to avoid contact with people currently suffering from a virus or other infection, and notify their doctor right away if they begin to experience the symptoms commonly associated with infections.

Low platelet levels can make it more difficult for the blood to clot which can cause serious complications in the event of injury or an accident that causes bleeding or severe bruising. Patients are advised to contact their doctor right away if they begin bleeding or suffer severe bruising.

This product is available in the following dosage forms:

  • Suspension
  • Capsule

Condition(s) treated

  • Tyrosinemia type 1

Type of medicine

  • Gastrointestinal Agent

Side Effects

Similar to many prescription medications, nitisinone can cause some unwanted side effects. Some of these symptoms will require further medical attention while others will likely dissipate on their own. Patients are advised to let their doctor know of any symptoms or side effects that cause them any concern, worsen over time, or do not dissipate after a few days. If you are unsure if the side effects that you are experiencing warrant further medical attention, it is best to err on the side of caution.

If you experience any of the side effects listed below it is important to contact your doctor right away for further medical advice:

Less likely:

  • Black, tarry stools
  • Difficulty seeing at night
  • Swollen or painful glands
  • Blindness
  • A sore throat
  • Bloody nose
  • Pinpoint red spots on the skin
  • Burning, dry, or itching eyes
  • Increased sensitivity to sunlight
  • Chest pain or discomfort
  • Eye redness, irritation, or pain
  • Coughing
  • Unexplained tiredness or weakness
  • Excessive eye tearing
  • Decreased vision
  • Fever
  • Chills
  • Painful or difficult urination
  • Change in color vision
  • Blurred vision
  • Blood in the urine or stools
  • Unexplained bleeding or bruising
  • Bleeding gums

Rare likelihood:

  • Agitation
  • Stiff neck
  • Drowsiness
  • Bluish color of the fingernails or lips
  • Irritability
  • Coughs with mucus
  • Hallucinations
  • Dizziness
  • Headaches
  • Difficulty breathing
  • Seizures
  • Confusion
  • Tightness in the chest
  • Back pain
  • Vomiting

There are other side effects that may occur as your body adjusts to the introduction of nitisinone into your system. These symptoms are typically not medically significant and should not cause you any worry. If any of the following occur and last longer than a few days, or if they become worse, contact your doctor for further medical advice:

Less likely:

Rare likelihood:

  • Abdominal pain
  • Seizures
  • Cool, pale skin
  • Nausea
  • Fast heartbeat
  • Slurred speech
  • Increased hunger
  • Nightmares
  • Depression
  • Shakiness
  • Cold sweats
  • Headaches

This list is comprehensive though you may experience side effects that are not listed here. If you experience any symptoms that last longer than a few days or become worse, contact your doctor for further medical advice. Patients who are unsure if their symptoms require further attention from their doctor are encouraged to contact their doctor in such situations.

Dosage

The guidelines listed below reflect the typical dosage information, however, if your doctor prescribes this medication to you in a different way, it is important that you follow those instructions. Patients who are taking nitisinone will often be advised to make certain changes to their diets; these instructions should be followed as closely as possible. If you do not feel that the medication is effective or is not working as expected, address these concerns with your physician right away. Do not ever take more or less nitisinone without first consulting with the prescribing physician. Patients should take care to always take their medications as medically directed.

Inform your doctor of any allergies that you may have. Especially those to other medications, food, animals, cleaning solutions and other substances. If you experience any type of allergic reaction while taking nitisinone, let your doctor know right away.

For patients taking the capsule method of delivery:

The medication should be taken without food and on an empty stomach. Take your capsule either two hours after your meal or at least one hour prior to eating.

Patients that are unable to successfully swallow the capsule can open it and sprinkle the contents onto applesauce or into the water. Be sure to take the medication directly after you have mixed it without delay.

For patients utilizing the suspension method of delivery:

This medication delivery method can be taken with or without food as it fits the patient's preference. Prior to taking the oral suspension, allow the medication to come to room temperature for at least one half to one hour. Be sure to thoroughly shake the bottle to ensure that the cake is fully dissolved. Measure the dosage amount with the oral syringe that is included with the medication. Be sure that all particles have settled before measuring out the dosage.

Your dose will typically be determined by calculating the appropriate amount of medication based on your weight. For adults, this dosage is typically 0.5 milligrams for every kilogram of weight, taken twice each day. The maximum dosage per day is typically 1 milligram for every kilogram of weight taken twice each day.

Children who are prescribed this drug will typically receive their dosage as determined by their doctor with the typical guidelines being 0.5 milligrams for each kilogram of body weight with 1 milligram per kilogram representing the maximum dosage amount taken two times per day.

If you miss a scheduled dose, take it as soon as you realize that it has been missed. However, if it is close to your next scheduled dose you will need to skip it. Patients that miss a dose and are unsure what to do should contact their pharmacist for further direction, it is important that a double dose is not taken.

Major Drug Interactions:

There are certain medications whose use is contraindicated with nitisinone and should be avoided. If you are currently taking Cyclophosphamide your doctor may alter the way in which you take one or both of the medications. Follow the prescription provided by your doctor even if it differs from what you read in this report. Your doctor may prescribe nitisinone even if you are taking a drug that can cause an increased risk of side effects or other complications, although they may alter the way that you take one or both of the medications.

There are certain lifestyle habits such as smoking or other tobacco products and the regular intake of alcohol that your doctor should be aware of prior to the start of your nitisinone course of treatment. Alert your doctor if you make any substantial changes to your lifestyle or in the way that you take any of your medications, even those that are available over the counter without a prescription. Do not change the way that you are taking this medication without first speaking to your doctor.

Notify your doctor of any changes to the way that you take any prescription medications or if you begin taking a new medication while on your nitisinone course of treatment. This information should include any non-prescription drugs in addition to those that require a prescription, as well as any herbal remedies and vitamin or mineral supplements.

If you suffer from any of the following medical conditions your course of treatment may be more complicated, or you may be more likely to suffer from unwanted side effects. The use of this medication can also affect the development of these pre-existing conditions. Be sure to inform your doctor of any significant reactions or side effects that you experience while taking nitisinone:

Warnings

While you are taking this medication your doctor will likely schedule follow-up visits as well as diagnostic testing, such as urine and blood tests. It is important that all appointments are kept as scheduled and that you undergo all testing as directed.

Patients are advised to have their vision tested on a regular basis as the use of nitisinone can cause eye care issues. Consult your doctor or ophthalmologist right away if you experience any of the following:

  • Difficulty seeing at night
  • Blurred vision

It may be more likely to experience infections when taking nitisinone as it can reduce the number of white blood cells contained in your bloodstream, albeit on a temporary basis. Your platelet level may also be decreased which can make it more difficult for your blood to clot. It is important to limit your contact with people who are exhibiting the symptoms of infection such as:

  • Fever
  • Pain in one or both sides
  • Chills
  • Lower back pain
  • Hoarseness
  • Coughing
  • Painful urination

Contact your doctor right away if you experience:

  • Pinpoint red spots on the skin
  • Blood in the urine or stools
  • Unexplained bleeding or bruising
  • Black, tarry stools

Be aware that the oral suspension delivery method of nitisinone includes glycerol among its ingredients and may, therefore, cause the following symptoms:

Due to the potential temporary decrease in platelets contained in your bloodstream, it is important to exercise caution when using any sharp item, such as scissors, razors or nail clippers. It is advisable to avoid any contact sports or other activities that have the potential to cause injury or bruising.

Storage

It is always best practice to store medications in the original packaging. This medication should be stored in the refrigerator until it is time to administer it, do not freeze nitisinone. Once opened, you can keep nitisinone at room temperature for a period not longer than 60 days. If at the end of 60 days you have medication remaining, it is important to properly dispose of it as it may not be safe or effective.

Keep this and all medications out of the reach of both pets and children.

Double check with your pharmacist to learn more about the proper disposal of this medication as it is important to dispose of any excess, expired, or unused medication.

Summary

Patients who suffer from a hereditary condition that results in too much tyrosine in their blood have found relief by taking the prescription drug known as nitisinone. Tyrosinemia type 1 is not curable with this medication, but its use can help to slow the debilitating effects of the disease. The effective treatment of tyrosinemia type 1 will also require significant changes to the patients' diets as well as other lifestyle habits.

This medication may also lower the level of white blood cells and platelets in the bloodstream. Patients who are taking it are strongly cautioned to avoid infections and physical injuries that can cause bleeding and bruising. Whenever possible, limit your interaction with people who are currently suffering from a virus or other infection. It is important to notify your doctor right away if you feel that you are coming down with an infection.