Medication Information Leaflet

What is this medication for?

Riociguat is used to treat high blood pressure in the lungs, known as pulmonary hypertension. More specifically, it can help treat a subgroup of pulmonary hypertension patients with pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension (CTEPH).

Riociguat is a type of medication called a soluble guanylate cyclase stimulator. It works by widening the pulmonary arteries (the blood vessels that send blood from the heart to the lungs to receive oxygen), making it easier for the heart to pump blood through the lungs. This should improve symptoms such as breathlessness and increase your ability to exercise.

How should I take or use this medication?

• Do not stop taking your medication without checking with your healthcare professional. If you stop taking your medication, you may experience a worsening of your condition.
• You may take this medication with or without food.
• Riociguat is initially started at a lower dose. Your condition will be monitored closely. Your doctor may later adjust your dosage to better control your condition.

What should I do if I forget to take or use this medication?

If you forget to take a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose. Then take your next dose at the usual time. Do not take two doses to make up for the missed dose.

What precautions should I take when taking or using this medication?

Inform your healthcare professional if:

• You are allergic to this medication or any of the other ingredients of this medication.
• You are pregnant, planning to become pregnant, or breastfeeding.
  • As this medication may cause serious birth defects, female patients of childbearing age should take precautions by using at least 2 reliable methods of contraception to avoid pregnancy.
  • If you have an intrauterine device, a progesterone implant or had a tubal sterilisation, these methods can be used alone and no other form of birth control is needed.
  • If you suspect you may be pregnant, inform your doctor as soon as possible.
  • You should avoid family planning for at least 1 month after stopping this medication.
• You have liver or kidney problems.
• You have a condition known as pulmonary veno-occlusive disease (narrowing of the pulmonary veins).
• You are smoking or have any changes to your smoking habits. Smoking may decrease the amount of Riociguat that stays in your body.
• You are taking any other medications, including supplements, traditional medications and herbal remedies.

What are some common side effects of this medication?

These side-effects may be minimized by starting with a lower dose and may improve or go away with time. Inform your healthcare professional if it becomes bothersome or does not go away.

• Giddiness, low blood pressure, fainting
  • Rise slowly from a sitting or lying position to reduce giddiness when changing position
• Swelling of the hands, legs, feet and ankles
• Headache
• Nausea, vomiting
• Diarrhea
• Heartburn

What are some rare but serious side-effects that I need to seek medical advice immediately?

Very rarely, riociguat may cause abnormal bleeding. These symptoms may include one or more of the following:

• Coughing up blood, vomiting blood/ coffee-ground like vomit
• Vaginal bleeding
• Frequent unexplained nose bleeds
• Unexplained bruising on the skin

Rarely, riociguat may cause low haemoglobin (a type of protein in red blood cells) levels. These symptoms may include one or more of the following:

• Feeling more tired/weaker than usual
• Shortness of breath

The symptoms of a drug allergy include one or more of the following:

• Swollen face/eyes/lips/tongue
• Difficulty in breathing
• Itchy skin rashes over your whole body

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately.

What food or medication should I avoid when I take or use this medication?

Avoid taking grapefruit or its juice when you are taking this medication as grapefruit may interact with your medication and increase the risk of side-effects.

If you are taking riociguat, you should avoid certain medications. Examples include: 

• Nitrates (e.g. glyceryl trinitrate, isosorbide dinitrate, isosorbide mononitrate)
• Phosphodiesterase-5 inhibitors (e.g. sildenafil, vardenafil, tadalafil)
• Non-specific phosphodiesterase inhibitors (e.g. theophylline, dipyridamole)

Some medications may interact with riociguat and affect its effectiveness or increase the risk of side-effects. However, these medications may also be important for your treatment. Inform your healthcare professional of the other medications you are currently taking. Examples include:

Medications for fungal infections (e.g. itraconazole, ketoconazole)

Medications for viral infections (e.g. atazanavir, darunavir, ritonavir)

Riociguat should be taken one hour apart from antacids (A type of medication used for reducing gastric acid).

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children.
 

How do I throw away this medication safely?

Disclaimer

Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on March 2025