Oral medications and injections

Photo of a woman with psoriasis on her elbow (PantherMedia / Hriana)

Topical treatment alone doesn’t always help enough in people with moderate to severe psoriasis. Then medications that have an effect throughout the entire body are considered. They can be taken as tablets or injected. Because of the possible side effects, it is a good idea to be well informed about their pros and cons.

Mild plaque psoriasis can usually be effectively treated with topical medications. Additional treatment may be needed for moderate to severe psoriasis. UV light therapy is often tried first. If that doesn't help either, oral medications and injections are considered. This is called "systemic treatment" because the medicines enter the bloodstream and have an effect throughout the entire body (or “system”). The treatment typically begins with one of these drugs:

  • Methotrexate (trade names: Lantarel, Metex, MTX Hexal, Methotrexat AL, for example)
  • Fumaric acid esters (trade name: Fumaderm)
  • Ciclosporin (trade names: Ciclosporin Pro, Ciqorin, Sandimmun, for example)
  • Less common: Acitretin (trade name: Acicutan)

If these medications don't provide enough relief for psoriasis or are unsuitable for some other reason, treatment with biological treatments (biologics) is possible. This group of drugs manufactured using biotechnology includes:

  • Adalimumab (Humira)
  • Etanercept (Benepali, Enbrel)
  • Infliximab (Flixabi, Inflextra, Remicade, Remsima)
  • Ixekizumab (Taltz)
  • Secukinumab (Cosentyx)
  • Ustekinumab (Stelara)

Another option is apremilast (Otezla). It belongs to a separate class of drugs.

Before and during treatment

Because systemic treatment affects the entire body, there is a higher risk of serious side effects. So it's a good idea to find out about the advantages and disadvantages of the different medications before deciding on a treatment. That includes talking with your doctor about any possible reasons why you shouldn't take them – like interactions with other medications or treatments.

Most of the medicines used for psoriasis also affect your immune system. So, before and during the treatment, certain blood tests are done on a regular basis to detect possible harmful effects such as serious infections, or problems with your liver or kidneys, as early as possible.

Assessing the success of treatment

Studies often use the PASI index ("Psoriasis Area and Severity Index") to find out how effective a particular treatment is. When using the index, doctors examine the skin and assess

  • the degree of redness,
  • the degree of scaling (flaky skin),
  • the thickness of the skin, and
  • the size of the affected area of skin.

A mathematical formula is then used to calculate the PASI as a measure of how severe the psoriasis is. A value of 0 means “no psoriasis,” and values of 10 or more are used for moderate to severe psoriasis. Treatment is considered to be successful if the PASI score is reduced by at least 75% during the treatment – which would correspond to a drop from 10 to 2, for example.

Fumaric acid esters

Fumaric acid esters (trade name: Fumaderm) are taken in the form of tablets.  The dose is gradually increased over the first few weeks to make it easier to tolerate: from 30 mg once daily during the first week of treatment to three times daily during the third week. After that, the dose per tablet is increased to 120 mg. The overall number of tablets continues to be increased until symptoms improve. The maximum dose is six 120 mg tablets per day. There should be a considerable improvement in the psoriasis after six to eight weeks at the latest.

In studies, fumaric acid esters relieved the symptoms of plaque psoriasis in an estimated 30 to 40 out of 100 people. But the studies were small and weren’t carried out well, so these results aren’t very reliable.

Side effects

Fumaric acid esters often cause diarrhea, nausea and stomach ache. They can also lead to facial flushing (redness and a hot sensation in the face). One study found that about 60 out of 100 people had at least one of these side effects. But they sometimes go away after a while, and none of the participants stopped their treatment because of them. People are advised to take fumaric acid esters with milk in order to increase the tolerability.


Because gastrointestinal side effects are so common, fumaric acid esters are not suitable for people who already have stomach or bowel problems, such as a gastric (stomach) ulcer. This drug may also lower the number of immune cells in the bloodstream, so it is not recommended for people who have a blood-related disease. Women who are pregnant or breastfeeding shouldn’t take fumaric acid esters because there hasn’t been enough research in this group of women.

Methotrexate (MTX)

Aside from being used to treat plaque psoriasis, methotrexate is also used to treat inflamed joints. It inhibits the inflammatory response and is also supposed to 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 muscle tissue, or into a vein. The tablet should be taken in the evening and swallowed with a lot of water, but not with a meal or together with milk. Doses between 5 and 30 mg are possible. Treatment typically starts with a 7.5 mg dose, which is then increased if necessary.

In studies methotrexate relieved psoriasis symptoms considerably in about 20 to 30 out of 100 people.

Side effects

Methotrexate can cause gastrointestinal 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 lowered by also taking low-dose folic acid (5 to 10 mg) once a week.

Over time, the use of methotrexate can affect the functioning of the liver and increase the likelihood of serious liver disease. Many people who take methotrexate have abnormal results in liver function tests. But, according to the studies done so far, actual damage to the liver is rare.


People who drink a lot of alcohol or who already have a serious liver disease are advised not to take methotrexate. The drug should also not be used by anyone with an acute gastric or duodenal ulcer or anyone who has a serious kidney disease.

Methotrexate isn’t suitable for women who are pregnant or breastfeeding, or for men or women trying to have a baby. Contraception should be used for another six months after the end of treatment with methotrexate.


Ciclosporin is taken as a capsule or solution in the morning and in the evening. The dose is based on body weight. Treatment is typically started with a daily dose of 2.5 mg per kilogram (kg) of body weight. So someone with a body weight of 80 kg (about 176 pounds) would start with a daily dose of 200 mg (2.5 x 80) – taking 100 mg in the morning and 100 mg in the evening. If there is no improvement after four weeks, the dose can be increased to a maximum of 5 mg per kg of body weight.

Studies have found ciclosporin to be effective at relieving the skin changes caused by 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 ciclosporin for more than a few months. Longer treatment may be considered for people with severe psoriasis who respond well to the drug, in order to prevent it from coming back. But based on the latest medical knowledge, ciclosporin should not be used for longer than one or at most two years.

Side effects

Ciclosporin may cause unusual skin sensations such as tingling, numbness or pins and needles. Other possible side effects include headaches and painful joints, muscle twitching, increased hair growth and high blood pressure. It also increases the risk of infections.


Ciclosporin may affect the functioning of the kidneys and liver. So it is not suitable for people who have kidney failure. The same applies to people who have cancer or who have had cancer in the past. Ciclosporin is not a good treatment option for people with untreated or poorly managed high blood pressure because it can increase blood pressure.

It should also not be taken during “psoralen plus ultraviolet A therapy” (PUVA) because the combination of ciclosporin and PUVA significantly increases the risk of skin cancer. People who have already had many PUVA treatments are also advised not to use ciclosporin.

To avoid drug-drug interactions, it is important to tell your doctor what medication you are already taking. This also applies to herbal products. For instance, St. John's Wort can weaken the effect of ciclosporin.

Women who are pregnant or trying to get pregnant should only take ciclosporin in exceptional cases. It is currently believed that ciclosporin can increase the risk of complications during pregnancy, such as premature birth. Ciclosporin isn’t suitable for women who are breastfeeding either.


Acitretin used to be a common treatment for plaque psoriasis. Its effectiveness has hardly been tested in studies, though. Experts assume that it is much less effective in treating psoriasis than other medications are. Nowadays it is only very rarely prescribed. It is taken once daily in the form of a tablet, preferably with a meal or milk.

Acitretin is considered as an alternative if other medications are not an option. It can also be combined with UVB light therapy to increase its effectiveness. When used in combination with light therapy, acitretin is taken at a lower dose in order to avoid side effects as much as possible.

Side effects

Acitretin often causes dry skin, dry lips and dryness of the mucous membranes lining the mouth. The eyelids can also dry out and become inflamed. So contact lenses should not be worn during treatment. Acitretin makes both the eyes and the skin more sensitive to light and sometimes causes hair loss. These side effects go away as soon as you stop using the medication.

Because acitretin doesn't suppress the immune system – unlike most other psoriasis drugs – the risk of infections doesn’t increase.

The combination of acitretin and “psoralen plus ultraviolet A therapy” (PUVA) may cause serious side effects, and is not recommended.


Women who are pregnant or planning a pregnancy should not take acitretin because it can lead to defects in unborn babies. Sexually active women and girls should only use acitretin if they practice safe sex. But this medicine can make the birth control pill less effective. So it is important to use additional contraception such as a condom. After ending treatment with acitretin, women should still use contraception for another three years in order to prevent birth defects. They should also wait three years before trying to get pregnant. Women who are breastfeeding should not take acitretin either.

Acitretin is also not an option for people who have severe liver or kidney disease. Because it increases the levels of certain lipids in the blood, it isn’t suitable for people who are at a higher risk of developing cardiovascular disease.

Acitretin should not be taken together with ciclosporin or methotrexate.

Oral steroids

Some doctors often still prescribe oral steroids (steroid tablets), particularly for adults with severe eczema. But these medications are no longer recommended for the treatment of psoriasis, and should only be used in absolutely exceptional cases. This is because the psoriasis can return and be even worse than before once you stop taking the tablets (rebound effect). Also, oral steroids can have serious side effects when taken for a long period of time.


Apremilast (trade name: Otezla) belongs to a new class of drugs called PDE4 inhibitors, and is taken in tablet form. The recommended dose is 30 mg twice per day, taken about 12 hours apart. The dose is 10 mg on the first day of treatment, and is then increased to 60 mg 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 cannot be considered as treatment options for other reasons.

Biological drugs (biologics)

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

Biological drugs are very effective. Studies have shown that they can clearly relieve psoriasis symptoms in about 70 out of 100 people.

Side effects

Because all biological drugs suppress the immune system, they can increase the risk of infections. In particular, they increase the risk of urinary tract infections and upper respiratory tract infections such as 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.

The results of studies have provided the following estimates concerning these side effects:

  • Biological drugs cause side effects in about 5 out of 100 people.
  • About 4 out of 100 people stop their treatment because of side effects.
  • About 1 out of 100 people develop a serious infection because of the biological drug treatment.

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


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
  • a serious infection

How biological drugs are used


Adalimumab (trade name: Humira) is injected under the skin using a pre-filled pen or a pre-filled syringe. The first dose is 80 mg, and all subsequent doses are 40 mg. The second dose is injected one week after the first, and all other doses are injected every other week after that. The psoriasis should get better within 16 weeks of starting the treatment.


Etanercept is injected under the skin once or twice a week using a pre-filled pen or a pre-filled syringe. The typical dose is 50 mg per week, but it can be temporarily increased to 100 mg as needed. A significant improvement should occur after twelve weeks of treatment.


Infliximab is given in the form of an infusion (an IV drip), entering the bloodstream directly through a vein. The dose is based on body weight (5 mg per kg of body weight). The second infusion is given two weeks after the first, and the third is given four weeks after the second. After that the rest of the infusions are given every eight weeks. The symptoms should improve significantly after 14 weeks of treatment.


Secukinumab (trade name: Cosentyx) is injected under the skin using a pre-filled pen or a pre-filled syringe. During the first four weeks of treatment it is injected once a week, and after that it is injected once a month. The dose is 300 mg per week. Because the pre-filled syringes contain 150 mg of the drug, two injections are needed per dose. A clear improvement in the psoriasis symptoms should be apparent within 16 weeks of treatment.


Ustekinumab (trade name: Stelara) is injected under the skin using a pre-filled syringe. The first two injections are given four weeks apart. After that, the drug is only injected every twelve weeks. The dose is 45 mg per syringe. Higher doses of the drug can be used in people who weigh more than 100 kg (about 220 pounds). There should be a significant improvement in psoriasis symptoms within 28 weeks.

Deciding on a medication

Experts don't agree on which of these medications should be tried first. Various factors play a role in the choice of medication – for example, whether you have health problems that make some of the medications unsuitable, or how well you tolerate a certain drug.

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 biological drugs).