Oral medications and injections

Treatment with tablets or injections is called "systemic treatment" because the medicines enter the bloodstream and have an effect throughout the entire body (or “system”). The treatment is typically started with one of these drugs:

• methotrexate
• fumaric acid esters (sometimes called fumarates)
• cyclosporine

If these medications don't relieve the psoriasis symptoms enough or aren't suitable for other reasons, treatment with apremilast or a biologic is possible. Biologics are drugs that are manufactured using biotechnology. They include:

• adalimumab
• brodalumab
• etanercept
• guselkumab
• infliximab
• ixekizumab
• risankizumab
• secukinumab
• tildrakizumab
• ustekinumab

The first drug to be tried out will depend on various factors, such as whether the person has health problems that mean they can't use certain medications.

If you have psoriasis on your skin as well as inflamed joints (psoriatic arthritis), it makes sense to use medications that will also help fight the inflammation in the joints (methotrexate and biologics).

Because systemic treatment affects the entire body, there is a higher risk of serious side effects. So it's a good idea to talk to your doctor and carefully weigh the pros and cons of this kind of treatment. It's important to tell him or her whether you

• are taking other medications (including herbal products) because they could interact with the systemic psoriasis medication,
• have other illnesses, or
• are pregnant, breastfeeding a child or (still) planning to have a child in the future. The latter is also true for men. When taking certain medications, it's important to use effective contraception for a few months after stopping the treatment too.

The risk of serious side effects is low for most psoriasis medications. These side effects include severe infections and damage to the liver or kidneys. To try to prevent complications or detect them sooner, blood tests are done regularly. If, for instance, the test shows that your kidney or liver function is abnormal, the dose can be adjusted or you can stop taking the medication. People who have severe kidney or liver disease are only able to use certain medications.

Aside from being used to treat plaque psoriasis, methotrexate is also used to treat inflamed joints. It reduces the inflammation and can also prevent joint damage in arthritis.

Methotrexate is used once a week in the form of a tablet or injection. It can be injected under the skin, into a muscle, or into a vein. Doses between 5 and 30 mg are possible. Treatment typically starts with a 7.5 mg dose, which is then increased if necessary.

The tablet should be taken in the evening and swallowed with a lot of water. It shouldn't be taken with a meal, if possible, and should never be taken with milk.

Research has found that methotrexate relieves psoriasis symptoms in about 20 to 30 out of 100 people.

Methotrexate can cause gastrointestinal (stomach and bowel) problems such as nausea and make infections more likely. Injecting methotrexate is better tolerated by the stomach and bowel. Temporary hair loss is a less common, but possible, side effect.

Some side effects arise from methotrexate interfering with the effect that folic acid has in the body. Folic acid is a type of vitamin B that plays a role in the production of new cells and cell division. The risk of these side effects can be reduced by also taking low-dose folic acid (5 to 10 mg) once a week.

Because methotrexate can affect your liver function, it is not suitable for people who drink a lot of alcohol or already have severe liver disease. The drug should also not be used by anyone with an acute gastric (stomach) or duodenal ulcer.

Fumaric acid esters are taken in the form of tablets. To make it easier to tolerate, the dose is gradually increased over the first few weeks: from 30 mg once daily during the first week of treatment up to a maximum of 600 mg per day. The dose is increased until the symptoms improve a lot. Fumaric acid esters should be taken during or after a meal, together with a drink. Swallowing it with milk is supposed to help protect your stomach and bowel.

Two fumaric acid esters have been approved for the treatment of psoriasis in Germany: Fumaderm and Skilarence. Studies have found that they relieve the symptoms of plaque psoriasis significantly in 15 out of 100 people. These two medications work equally well.

Fumaric acid esters often cause diarrhea and stomach ache, and sometimes lead to nausea and vomiting too. They can also lead to facial flushing (redness and warmth in the face). About 25 out of 100 people will have at least one side effect. The side effects may go away or improve over time. The side effects in studies were sometimes so bad that the participants stopped taking the medication.

Because gastrointestinal side effects are so common, fumaric acid esters aren't suitable for people who already have stomach or bowel problems, such as a gastric (stomach) ulcer. This medication may also lower the number of immune system cells in the bloodstream, so it's not recommended for people who have a blood-related disease.

Cyclosporine is taken in the morning and/or evening before meals, at the same time every day if possible. Important to know: It should not be taken with grapefruit juice.

The dose of cyclosporine is determined based on the person’s body weight. Treatment is typically started with a daily dose of 2.5 mg per kilogram (kg) of body weight. So someone who weighs 80 kilograms (about 176 pounds) would start with a daily dose of 200 mg. If there is no improvement after four weeks, the daily dose can be increased to a maximum of 5 mg per kilogram of body weight.

Studies have found that cyclosporine relieves the skin problems caused by plaque psoriasis. It led to a clear improvement in about 25 out of 100 people. The effect usually became noticeable after about four weeks of treatment.

Doctors typically advise people not to take cyclosporine for more than 2 to 4 months because it may cause kidney damage after that. Longer treatment may be considered in people with severe psoriasis who respond well to the drug, in order to prevent it from coming back. But even then cyclosporine shouldn't be used for longer than one year, or two years at the most.

Cyclosporine may cause unusual skin sensations such as tingling, numbness or pins and needles. Other possible side effects include swollen gums and high blood pressure. It also increases the risk of infections such as acute bronchitis.

Cyclosporine isn't suitable for people who have cancer or who have had cancer in the past. Because it can increase blood pressure, it also isn't suitable for people with untreated or poorly managed high blood pressure.

This medication shouldn't be taken during “psoralen plus ultraviolet A therapy” (PUVA) either because the combination of cyclosporine and PUVA significantly increases the risk of non-melanoma skin cancer. People who have already had many PUVA treatments are also advised not to use cyclosporine.

Apremilast (trade name: Otezla) belongs to a new class of drugs called PDE4 inhibitors. The tablets are taken twice a day, about 12 hours apart, and not with meals. The dose is 10 mg on the first day of treatment, and is then increased to 60 mg per day within the first week.

Psoriasis should improve significantly within 24 weeks when treated with apremilast. If it doesn’t, the treatment is usually stopped. Apremilast can be used if other oral medications or PUVA therapy aren’t effective or aren't suitable for other reasons.

Studies have found that apremilast relieves the symptoms of psoriasis in about 20 out of 100 people.

About 10 out of 100 people have side effects such as diarrhea and nausea. They mainly occur in the first few weeks of treatment and can lead to weight loss.

In rare cases, apremilast can also affect your mood and make you feel suicidal. You should stop taking the medication if these side effects occur.

Apremilast is not suitable for people who have mental health problems or take other medication that can affect their mental health.

Acitretin used to be a common treatment for plaque psoriasis. Its effectiveness has hardly been tested in studies, though. Experts believe that it is much less effective in treating psoriasis than other medications are. So it is only very rarely prescribed nowadays. Acitretin may be considered as a treatment option if other medications can't be used.

Some doctors often still prescribe oral steroids (steroid tablets), particularly for adults with severe eczema. But these medications aren't recommended for the treatment of psoriasis, and should only be used in absolutely exceptional cases. This is because the psoriasis can return once you stop taking the tablets and may then be even worse than it was before (rebound effect). Also, oral steroids can have serious side effects when taken for a long period of time.

Treatment with biological drugs is usually considered for people who haven’t benefited enough from UV light therapy or medications such as cyclosporine or methotrexate. Some biologics can also be used even if no other treatments have been tried.

Biologics are either injected under the skin with ready-to-use pens or syringes, or given as infusions (IV drips) – one or several weeks apart, depending on the drug used.

Biologics are very effective. Studies have shown that they can clearly relieve plaque psoriasis in 40 to 70 out of 100 people. The symptoms generally improve a lot within 3 to 4 months.

Because biologics are injected, the treatment can also cause redness, itching, swelling and bruising at the site of injection. These kinds of reactions are quite common, but the body can get used to the injections after some time.

All biologics weaken the immune system so they increase the risk of infections. In particular, they increase the risk of urinary tract infections like cystitis and upper respiratory tract infections such as acute bronchitis. They also lead to a higher risk of more serious infections, such as infections of the lungs, the heart or deeper layers of skin.

Studies have provided the following estimates concerning these side effects:

• Biologics cause side effects in up to 10 out of 100 people.
• About 4 out of 100 people stop their treatment because of side effects.
• In up to 1 out of 100 people the biologic drug leads to a serious side effect such as a severe infection.

But most of the studies only lasted 3 to 4 months. The risk of side effects may increase if the treatment is used for longer than that.

The use of biological drugs is not recommended for people who have

• severe kidney or liver failure,
• cancer now or had it in the past,
• multiple sclerosis, or a sibling or parent who has it,
• hepatitis or had it in the past,
• tuberculosis or had it in the past,
• severe heart failure, or

• a serious infection.