Understanding Sickle Cell Disease (SCD) and Hydroxyurea
What is Sickle Cell Disease?
Sickle Cell Anemia (SCA) is one of a group of inherited disorders known as Sickle Cell Disease (SCD).
Sickle Cell Disease affects red blood cells.
Normal red blood cells are round and flexible and can move easily through blood vessels.
For people with SCD, their red blood cells become stiff and curved (or shaped like a “sickle”), causing these cells to stick to the lining of the blood vessels and block blood flow.
The blockages can cause crippling pain and other complications that can lead to hospitalization.
Red blood cells contain a substance called hemoglobin, which helps them carry oxygen from the lungs to other parts of the body. People with SCD don’t have regular hemoglobin in their red blood cells. This abnormal hemoglobin is what causes the red blood cells to sickle.
Sickle Cell Disease is an inherited blood disorder
It is believed to be caused by a genetic trait that may have evolved to provide protection against malaria. Therefore, it is most common in individuals whose ancestors came from malaria-prone areas of the world, including:
- Africa
- Central and South America
- The Caribbean
- Saudi Arabia
- India
- Mediterranean countries, such as Turkey, Greece and Italy
There are approximately 100,000 patients with SCD in the United States and millions with SCD globally
Common Symptoms and Complications of Sickle Cell Disease
Most of the symptoms and complications of SCD are caused by the curved red blood cells sticking to the lining of the blood vessels creating blockages to blood flow.
The most common symptoms of the disease include:
Additionally, SCD can cause further complications by causing harm to important organs like the brain, heart, lungs, kidneys, and eyes. This can lead to serious problems like vision loss or kidney failure.
But there is a treatment that may help with certain symptoms.
Learn more about an SCD treatment
What is Hydroxyurea?
Hydroxyurea (HU) is well established in the medical community as the "gold standard" treatment for sickle cell disease.
HU is a prescription medicine used to treat people with SCD since the 1980s.
HU helps your red blood cells stay larger, rounder, and more flexible – making them less likely to turn into a sickle or curved shape.
Importance of Early & Continued Treatment with Hydroxyurea
Hydroxyurea reduces the symptoms and complications that can arise from SCD. People with sickle cell disease who take HU have fewer:
- complications from sickle cell disease
- painful crises
- episodes of acute chest syndrome
- blood transfusions
- hospital stays
HU treatment can also prevent or slow down damage to your organs.
In children with SCD, organ damage begins early in life and worsens over time, but ultimately affects the brain, kidney, lung, spleen, bones, and eyes. This organ damage could lead to premature death.
It is important to treat symptoms of sickle cell disease as early as possible and to continue HU treatment your entire life to minimize any organ damage.
INDICATION AND IMPORTANT SAFETY INFORMATION
IMPORTANT SAFETY INFORMATION
WARNING: LOW BLOOD CELL COUNT and CANCER
See Full Prescribing Information for complete Boxed Warning.Low blood cell counts are common with SIKLOS, including low red blood cells, white blood cells, and platelets, and can be severe and life threatening. If your white blood cell count becomes very low, you are at increased risk for infection. Your healthcare provider will check your blood cell counts before and every 2 weeks during treatment with SIKLOS. Your healthcare provider may change your dose or tell you to stop taking SIKLOS if you have low blood cell counts. Tell your healthcare provider right away if you get any of the following symptoms: fever or chills; shortness of breath; body aches; unusual headache; feeling very tired; bleeding or unexplained bruising.
Cancer. Some people have developed cancer, such as leukemia and skin cancer, after taking SIKLOS for a long time. Your healthcare provider will check you for cancer. You should protect your skin from the sun using sunblock, hats, and sun-protective clothing.
WHAT IS THE MOST IMPORTANT INFORMATION YOU SHOULD KNOW ABOUT SIKLOS?
- SIKLOS can harm your unborn baby.
- For females taking SIKLOS who can become pregnant:
- You should talk with your healthcare provider about the risks of SIKLOS to your unborn baby.
- You should use effective birth control during treatment with SIKLOS and for at least 6 months after treatment with SIKLOS.
- Your healthcare provider will perform a pregnancy test before you start treatment with SIKLOS. Tell your healthcare provider right away if you become pregnant or think you may be pregnant.
- For males taking SIKLOS: SIKLOS can affect your sperm. If you have a female sexual partner who can become pregnant, you should use effective birth control during treatment with SIKLOS and for at least 6 months after treatment.
- SIKLOS may cause fertility problems in males. Talk to your healthcare provider if this is a concern for you.
WHO SHOULD NOT TAKE SIKLOS
Do not take SIKLOS if you are allergic to hydroxyurea or any of the ingredients in SIKLOS. See the Medication Guide for a list of the ingredients in SIKLOS.
WHAT SHOULD YOU TELL YOUR HEALTH CARE PROVIDER BEFORE TAKING SIKLOS?
Tell your healthcare provider about all of your medical conditions, including if you:
- have kidney problems or are receiving hemodialysis
- have liver problems
- have human immunodeficiency virus (HIV) or take HIV medicines. Taking SIKLOS with certain HIV medicines can cause serious reactions and may lead to death.
- have increased levels of uric acid in your blood (hyperuricemia)
- have a history of receiving interferon therapy or are currently receiving interferon therapy
- plan to receive any vaccinations. You should not receive “live vaccines” during treatment with SIKLOS.
- are pregnant or plan to become pregnant. See "What is the most important information I should know about SIKLOS?"
- are breastfeeding or plan to breastfeed. It is not known if SIKLOS can pass into your breast milk. Do not breastfeed during treatment with SIKLOS.
- are using a continuous glucose monitor (CGM) to test your blood glucose. Talk to the healthcare provider that prescribed your CGM about whether it is safe to use while you are taking SIKLOS.
- Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.
WHAT ARE THE POSSIBLE SIDE EFFECTS OF SIKLOS?
SIKLOS may cause serious side effects, including:
See "What is the most important information I should know about SIKLOS"
- Skin ulcers, including leg ulcers, and death of skin tissue (gangrene) have happened in people who take SIKLOS. This has happened most often in people who receive interferon therapy or have a history of interferon therapy. Your healthcare provider will decrease your dose or stop treatment with SIKLOS if you develop any skin ulcers.
- Enlarged red blood cells (macrocytosis). Macrocytosis is common in people who take SIKLOS and can make it difficult to detect a decrease of folic acid. Your healthcare provider may prescribe a folic acid supplement for you.
- Hemolytic Anemia, the fast breakdown of red blood cells, has happened in people who take SIKLOS. Tell your healthcare provider I you develop yellowing of your skin (jaundice) or blood in your urine. Your healthcare provider may do blood tests if you have persistent or worsening anemia not related to sickle cell anemia.
The most common side effects of SIKLOS in children include: infections and low white blood cells.
The most common side effects of SIKLOS in adults include: infections, headache, and dry skin.
These are not all the possible side effects of SIKLOS.
You are encouraged to report negative side effects of prescription drugs to the FDA at fda.gov/medwatch, or 1-800-FDA-1088.
Please read the Full Prescribing Information, including Boxed Warning, Medication Guide and Instructions for Use, at SIKLOSusa.com.
SIKLOS is a prescription medicine that is used to reduce the frequency of painful crises and reduce the need for blood transfusions in adults and children, 2 years of age and older, with sickle cell anemia with recurrent moderate to severe painful crises. It is not known if SIKLOS is safe and effective in children less than 2 years of age.
INDICATION AND IMPORTANT SAFETY INFORMATION
IMPORTANT SAFETY INFORMATION
WARNING: LOW BLOOD CELL COUNT and CANCER
See Full Prescribing Information for complete Boxed Warning.Low blood cell counts are common with SIKLOS, including low red blood cells, white blood cells, and platelets, and can be severe and life threatening. If your white blood cell count becomes very low, you are at increased risk for infection. Your healthcare provider will check your blood cell counts before and every 2 weeks during treatment with SIKLOS. Your healthcare provider may change your dose or tell you to stop taking SIKLOS if you have low blood cell counts. Tell your healthcare provider right away if you get any of the following symptoms: fever or chills; shortness of breath; body aches; unusual headache; feeling very tired; bleeding or unexplained bruising.
Cancer. Some people have developed cancer, such as leukemia and skin cancer, after taking SIKLOS for a long time. Your healthcare provider will check you for cancer. You should protect your skin from the sun using sunblock, hats, and sun-protective clothing.
SIKLOS is a prescription medicine that is used to reduce the frequency of painful crises and reduce the need for blood transfusions in adults and children, 2 years of age and older, with sickle cell anemia with recurrent moderate to severe painful crises. It is not known if SIKLOS is safe and effective in children less than 2 years of age.