What it does / How it works

Methotrexate is a disease modifying antirheumatic drug (DMARD) used to treat active psoriatic arthritis. It works by suppressing the immune system—stopping the body from attacking itself. This helps to slow the progression of the disease and save your joints and tissue from permanent damage. 

Time frame

Most people start to see treatment benefits about 6-8 weeks after starting methotrexate. Dose changes can take about a month to take effect. In some, methotrexate can be very effective as a long-term strategy to prevent flares.

Dosage Form

Methotrexate comes in an oral tablet formulation and as a vial for injection into the muscle or under the skin.

Dose and frequency

The dose required to achieve clinical efficacy varies between individuals. The recommended starting dose of methotrexate is between 5 and 10mg per week for the first one or two weeks followed by dose increases to a target of 25 mg per week. Take methotrexate as directed by your doctor for optimal dosing.

Potential Side Effects

Potential side effects include nausea, anorexia, mouth ulcers and tiredness. More serious side effects include liver, kidney, lung, and bone marrow problems. Methotrexate can also cause fetal death or birth defects involving the limbs and brain. Patients should ensure they are not pregnant before starting methotrexate and should consider methods of contraception while taking methotrexate. Patients looking to get pregnant after stopping methotrexate should consult their physician before doing so.

Although effective in many patients, methotrexate may increase your risk of infection because it suppresses the immune system. Vaccines can help to reduce your risk of certain infections. Talk to your doctor or pharmacist for more information.

How to manage side effects

Taking this medication with food can help to minimize side effects such as upset stomach, nausea, and diarrhea. Taking folic acid can also help. Folic acid is usually given daily except on the day methotrexate is taken. Taking folic acid or folinic acid (usually, once a week) can help to reduce side effects such as upset stomach, nausea, and diarrhea. Folic acid and folinic acid are considered equally efficacious but folic acid is usually less expensive. Talk to your doctor about whether you should consider taking folic acid or folinic acid as part of your treatment plan.

Some prescription and over the counter medications may interact with methotrexate and increase the risk of adverse reactions. It’s important to share what other medications and supplements you are taking with your doctor. Your doctor or pharmacist can help you manage or prevent these interactions.  

Monitoring and follow up

Prior to treatment, clinical and laboratory evaluation should be done to check for pre-existing hepatitis virus B and hepatitis virus C infection. Methotrexate is not recommended for patients with active or chronic hepatitis B or C infection. 

Liver damage and function tests should be performed several times prior to dosing and periodic blood tests should be done to check for liver problems and other side effects. Alcohol use must be limited. 

Cost considerations

Methotrexate is eligible for coverage under your provincial drug plan. Talk to your pharmacist for details. [LINK: See public insurance for more details.]

What it does / How it works

Sulfasalazine is a disease modifying antirheumatic drug (DMARD) used to treat psoriatic arthritis. It works by blocking inflammation and suppressing the immune system – stopping the body from attacking itself. This helps to slow progression of the disease and save your joints and tissue from permanent damage. 

Time frame

It can take 8-12 weeks to start seeing the benefits of sulfasalazine. 

Dosage Form

This medication is currently available as an oral tablet.

Dose and frequency

The dose required to achieve clinical efficacy varies between individuals. The recommended starting dose of sulfasalazine is 500 mg once daily for the first one or two weeks followed by dose increases up to a total of 2 to 3 grams daily split into three or four doses. Take this medication as directed by your doctor for optimal dosing.

Potential Side Effects

Side effects vary between people but can include nausea, vomiting, diarrhea, abdominal pain, and skin rash. If you notice a new spreading skin rash after starting the medication, stop taking it and speak to your doctor right away. In some rare cases, sulfasalazine can also cause liver and kidney damage. 

How to manage side effects

Taking this medication with food can help to minimize side effects such as upset stomach, nausea, and diarrhea. Let your doctor know if you are experiencing any new side effects such as dizziness, bruising, worsening/persistent infections, severe pain in the abdomen, or problems with urinating.

Monitoring and follow up

Your doctor will order regular blood tests to monitor your kidney and liver function. You might be tested for certain genetic mutations before starting this medication as people with a genetic mutation known as G6PD deficiency may be at higher risk of infection, bleeding, and poor healing. 

Cost considerations

Sulfasalazine is eligible for coverage under your provincial drug plan. Talk to your pharmacist for details. [LINK: See public insurance for more details.]

What it does / How it works

Cyclosporine is an immunosuppressant that works by blocking the release of certain “cytokines” which are signalling molecules that play a role in inflammation. In psoriatic arthritis, cytokines are involved in triggering the body to attack its own healthy cells. Doctors usually prescribe cyclosporine for management of severe flares. It often clears symptoms rapidly. Due to the risk of severe side effects, its use is usually limited to short-term treatment. 

Time frame

Cyclosporine is usually taken for 12 to 16 weeks. Once symptoms are adequately controlled, the dose may be decreased to the lowest effective dose with your doctor’s guidance. Treatment longer than 1 year is not recommended.

Dosage Form

Cyclosporine is available as an oral solution and capsule. 

Dose and frequency

The usual initial dose is 2.5 to 3 mg/kg/day given twice a day (12 hours apart) for about 4 weeks. It may be started at a lower dose and increased over time to minimize the risk of side effects. Dose adjustments are usually made in increments of 0.5 to 1.0 mg/kg/day. These are general guidelines and patients should always follow the directions provided by their doctor.

Potential Side Effects

Common side effects include headache, vomiting, diarrhea, muscle cramps, high cholesterol, and fatigue.

Patients taking cyclosporine may be at an increased risk of infections. Talk with your doctor or pharmacist about what vaccines may be recommended for you. 

This medication can cause damage to the kidneys if used for long periods of time. Therefore, cyclosporine is usually limited to short courses and is not usually taken for longer than a year or two, at most. Lab tests should be done regularly to monitor kidney function during treatment.

Patients may develop high blood pressure while taking cyclosporine. This can be treated with antihypertensive medications. Elevated blood pressure caused by cyclosporine use is usually reversible upon stopping the drug.

Patients should not use phototherapy during treatment with cyclosporine due to the increased risk of skin cancer.

How to manage side effects

Cyclosporine can interact with some prescription and over the counter medications leading to increased side effects including kidney damage. Your pharmacist can help you understand, manage, and prevent these interactions. Ongoing monitoring of kidney function and blood pressure is required to avoid permanent kidney damage and chronic hypertension. Due to the severity of certain side effects, long-term use of cyclosporine is not usually recommended.

Monitoring and follow up

Pre-treatment physical examination usually includes evaluation of blood pressure, kidney function and careful examination for tumours, particularly of the skin, to establish accurate baseline values and clinical status. Your doctor may monitor your kidney function and blood pressure during treatment. Routine blood tests are prescribed to monitor metabolic problems such as too much magnesium or uric acid in the blood.

Cost considerations

Cyclosporine may require special authorization in some provinces before it can be covered by the provincial drug plan. Talk to your doctor or pharmacist about coverage options. [LINK: See public insurance for more details.]

What it does / How it works

Leflunomide is a disease modifying antirheumatic drug (DMARD) used to treat moderate to severe psoriatic arthritis. It works by suppressing the immune system—stopping the body from attacking itself. This helps to slow the progression of the disease and save your joints and tissue from permanent damage. 

Time frame

Most people start to see treatment benefits about 6-8 weeks after starting leflunomide, but it may take up to 3 months to see full effect. In some, leflunomide can be very effective as a long-term strategy to prevent flares.

Dosage Form

Leflunomide comes in an oral tablet.

Dose and frequency

The dose required to achieve clinical efficacy varies between individuals. The recommended dose of leflunomide is 20 mg daily. The dose may be reduced to 10 mg daily if a higher dose is not tolerated. 

Potential Side Effects

Side effects vary between people but can include headache, diarrhea, nausea, vomiting, abdominal pain, hair loss, and skin rash. If you experience intolerable side effects, speak to your doctor right away. Because of leflunomide’s very long half-life (~18 days), side effects may persist for a long time after the dose is reduced or drug is stopped.

Although effective in many patients, leflunomide may increase your risk of infection because it suppresses the immune system. Vaccines can help to reduce your risk of certain infections. Talk to your doctor or pharmacist for more information.

Some prescription and over the counter medications may interact with leflunomide and increase the risk of adverse reactions. It’s important to share what other medications and supplements you are taking with your doctor. Your doctor or pharmacist can help you manage or prevent these interactions.  

How to manage side effects

Taking this medication with food can help to minimize side effects such as upset stomach, nausea, and diarrhea. Let your doctor know if you are experiencing any new side effects such as dizziness, bruising, worsening/persistent infections, severe pain in the abdomen, or problems with urinating.

Monitoring and follow up

Prior to treatment, clinical and laboratory evaluation should be done to check for pre-existing hepatitis B and hepatitis C infection. In some rare cases, leflunomide can cause gradual liver and kidney damage. Your doctor will order regular blood tests to monitor your liver and kidney function. 

Cost considerations

In some provinces, leflunomide may require special authorization before it can be covered by the provincial drug plan. Talk to your doctor or pharmacist about coverage options. [LINK: See public insurance for more details.]

(Brand Name: Otezla)

What it does / How it works

Apremilast is an immunosuppressant used to treat psoriatic arthritis. It reduces the activity of phosphodiesterase 4 (PDE4), an enzyme that regulates inflammation in the skin and joints. This helps to slow the progression of the disease and save your joints and tissue from permanent damage. 

Time frame

Patients can expect to see symptom improvement within 4 months of starting treatment. The length of treatment may vary, and it is important to follow your doctor’s instructions carefully. 

Dosage Form

Apremilast is available as an oral tablet.

Dose and frequency

The usual starting dose is 10 mg daily. This is usually increased up to a maintenance dose of 30 mg twice a day. It may be started at a lower dose and titrated up over time to minimize the risk of side effects such as nausea, diarrhea, and stomach upset. 

Potential Side Effects

Common side effects include diarrhea, nausea, vomiting, headache, and upper respiratory tract infections (e.g., common cold). Rarely, this medication can decrease appetite, worsen depression, and cause weight loss.

How to manage side effects

Side effects such as nausea, diarrhea, and stomach upset usually resolve within the first month of treatment. The medication should be swallowed whole, with or without food. 

Monitoring and follow up

Your doctor may assess your kidney function before starting treatment as a lower dose may be required for patients with severe kidney impairment. Your doctor may also monitor your weight regularly during treatment. 

Cost considerations

Apremilast is not covered in most provinces. [LINK: See public insurance for more details.]

(Brand Name: Xeljanz)

What it does / How it works

Tofacitinib inhibits Janus kinase (JAK) enzymes, which are involved in the growth of immune cells. In psoriatic arthritis, these immune cells target your own body and cause joint damage. Blocking the JAK enzymes prevents your body from triggering the immune response and can save your joints and tissue from permanent damage. 

Time frame

Some patients may see an effect within a week, but usually it can take up to 8 weeks to see full effect from tofacitinib.

Dosage Form

Tofacitinib is available as an immediate-release oral tablet.

Dose and frequency

The recommended dose of tofacitinib is 5 mg twice daily in combination with methotrexate or another agent that can stop joint damage.

Potential Side Effects

Tofacitinib is generally well tolerated. The most common side effects are diarrhea, nausea, headache, skin rash, and infections of the nose, sinuses, or throat (e.g., common cold). In some rare cases, tofacitinib can cause liver injury. The drug also increases the risk of shingles.

How to manage side effects

Taking this medication with food can help to minimize side effects such as upset stomach, nausea, and diarrhea. Let your doctor know if you are experiencing any new side effects such as dizziness, bruising, worsening/persistent infections, severe pain in the abdomen or sides, or problems with urinating. Obtaining shingles vaccination prior to starting this medication is recommended.

Monitoring and follow up

Prior to treatment, clinical and laboratory evaluation should be done to check for pre-existing hepatitis virus B and hepatitis virus C infection. Liver function tests will also be done at the beginning and regularly throughout treatment.

Your doctor can perform something called a “complete blood count” or CBC to monitor for the risk of infection, bleeding, and poor healing. 

Cost considerations

Tofacitinib may require special authorization in some provinces before it can be covered by the provincial drug plan. Talk to your doctor or pharmacist about coverage options. [LINK: See public insurance for more details.]

(Brand Name: Rinvoq)

What it does / How it works

Upadacitinib inhibits Janus kinase (JAK) enzymes, which are involved in regulating your immune system. In psoriatic arthritis, these immune cells target your own body and cause joint damage. Blocking the JAK enzymes prevents your body from triggering the immune response and can save your joints and tissue from permanent damage. 

Time frame

Some patients may start to see an effect 2 to 8 weeks after starting the medication, but it can take up to 6 months to see full effect from upadacitinib. 

Dosage Form

Upadacitinib is available as an extended-release oral tablet.

Dose and frequency

The recommended dose for psoriatic arthritis is 15mg once daily.

Potential Side Effects

Upadacitinib is generally well tolerated. The most common side effects are headache, cough, back pain, and nausea. This medication may also increase the risk of lung infections, urinary tract infections, or shingles. 

How to manage side effects

Taking this medication with food can help to minimize side effects such as upset stomach, nausea, and diarrhea. Swallow these tablets whole as they should not be split, crushed, or chewed. Let your doctor know if you are experiencing any new side effects such as dizziness, worsening/persistent infections, severe pain in the abdomen or sides, or problems with urinating. Obtaining shingles vaccination prior to starting this medication is recommended.

Monitoring and follow up

Prior to treatment, clinical and laboratory evaluation should be done to check for pre-existing hepatitis virus B and hepatitis virus C infection. Liver function tests may also be done at the beginning and regularly throughout treatment.

Your doctor can perform something called a “complete blood count” or CBC to monitor for the risk of infection, bleeding, and poor healing. 

Cost considerations 

Talk to your doctor or pharmacist about coverage options. [LINK: See public insurance for more details.]