Ustekinumab is a type of medicine called a human monoclonal antibody. This is used to treat moderate to severe plaque psoriasis. This drug suppresses the part of the immune system and modifies the process of inflammation.
Psoriasis causes cells to build up rapidly on the surface of the skin. This skin condition speeds up the life cycle of skin cells. The extra skin cells form red patches and scales that are itchy and sometimes painful. Psoriasis frequently comes and goes. The main goal of treatment is to stop the skin cells from growing so rapidly. Its signs and symptoms are different for everyone. Common signs and symptoms include:

• Small scaling spots that are commonly seen in children
• Red patches of skin covered with thick and silvery scales
• Dry, cracked skin that may bleed
• Pitted, thickened, or ridged nails
• Burning, itching, or soreness
• Swollen and stiff joints

Psoriasis patches can range from a few spots of dandruff-like scaling to major eruptions that cover large areas.

Most types of psoriasis go through cycles that flares for a few weeks or months. After, it subsides for a time or even going into complete remission. The cause of psoriasis is thought to be related to an immune system problem with T cells and other white blood cells called neutrophils in your body. The T cells usually travel through the body to defend against foreign substances. But if you have psoriasis, the T cells attack healthy skin cells by mistake, as if to heal a wound or to fight infection.

Ustekinumab may also be used to treat Crohn’s disease. This disease causes inflammation of your digestive tract that can lead to abdominal pain, weight loss, and severe diarrhoea. The inflammation often spreads deep into the layers of affected bowel tissue. Crohn’s disease can be both painful and debilitating that sometimes may lead to life-threatening complications. Signs and symptoms of the disease can range from mild to severe. They usually develop slowly but sometimes will come suddenly without a warning. When Crohn’s disease is active, signs and symptoms can be:

• Fatigue
• Fever
• Diarrhea
• Mouth sores
• Blood in your stool
• Abdominal pain and cramping
• Reduced appetite
• Weight loss
• Pain or drainage near or around the anus due to inflammation from a tunnel into the skin

Other people with Crohn’s disease also may have symptoms such as:

• Inflammation of the liver or bile ducts
• Inflammation of joints, eyes, or skin
• Delayed growth or sexual development in children

How does Ustekinumab work?
Ustekinumab works in the same way to the natural antibodies made by our immune system. Our natural antibodies recognize foreign invaders. It binds them and helps our immune systems to attack them and protect us from infections. Monoclonal antibodies like this drug are made in laboratories and are intended to recognize particular proteins similarly. Ustekinumab specifically recognizes and binds to two proteins produced by the body called interleukin-12 and interleukin-23. These are involved in causing inflammation.

By preventing the action of interleukin-12 and interleukin-23, Ustekinumab helps decrease the inflammation and other symptoms of psoriasis. Preventing the action of these interleukins can as well lessen the inflammation in the joints in people with a form of arthritis that can happen alongside psoriasis. This is called psoriatic arthritis. Ustekinumab improves the arthritic symptoms and physical function of the joints in this condition. When treating arthritis, Ustekinumab is referred to as a disease-modifying antirheumatic drug (DMARD).

How to use Ustekinumab?
The dosage is based on your medical condition, age, and response. This medication is given by injection under your skin as directed by your doctor. You will receive one dose followed by a second dose 4 weeks later. Then, this medication is given every 3 months.
When given under the skin, should be injected in either the buttock, upper arms, abdomen, or thighs. It is important to change the location of the injection site under the skin. Choose a different injection site in each dose. Do not inject into skin that is infected, sore, or irritated. Use this medication regularly to get the most benefit from it.

Before using the product, check it visually for any particles or discolouration. This is a colourless to the light yellow solution and may have a few translucent or white particles. Do not use this if it is discoloured or cloudy. Clean the injection site as well with rubbing alcohol before injecting.

What are the side effects of Ustekinumab?
Common side effects:

• Skin rash or itching
• Diarrhea
• Tired feeling
• Headache
• Cold symptoms (Sore throat, sneezing, or stuffy nose)

This medication can affect your immune system and can lower the ability of your body to fight infection. Let your doctor know if you develop signs of an infection such as:

• Persistent nausea or vomiting
• Severe stomach pain
• Cold or flu symptoms
• Chills/fever
• Worsening swelling, redness, or tenderness at the injection site after 2 days

Warnings and Precautions

• Before having Ustekinumab, tell your doctor if you are allergic to it or if you have any allergies. This product may have inactive ingredients which can cause allergic reactions or other problems.
• Tell as well your doctor if you have any medical history especially hepatitis, tuberculosis, or cancer.
• Ustekinumab can make you more likely to get infections or may worsen any current infections. Therefore, do not have vaccinations or immunizations without the consent of your doctor.
• Avoid having BCG vaccines for 1 year after completing the treatment with Ustekinumab. Avoid as well as contact with people who have infections that may spread to others.
• Inform your doctor if you have any other medications (nonprescription, prescription, or herbal products).
• This medication should only be used when needed in pregnancy.
• If you are breastfeeding women, consult your doctor first before taking this drug.