Riociguat

Common side effects include:

• 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, vomitting
• Diarrhea
• Heartburn

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.

Rare side effects include: 

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.

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 avoid getting pregnant.
• Avoid pregnancy by using two reliable forms of birth control during treatment, and for one month after stopping treatment with riociguat. 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 have liver or kidney problems.
• You have a condition known as pulmonary veno-occlusive disease (narrowing of the pulmonary veins).
• You smoke, or stop smoking during treatment.
• You are taking any other medications, including supplements, traditional medications and herbal remedies.

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. Some examples are: 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).