Medication Information Leaflet
This medication is used to treat hyponatremia, where the sodium level in the blood is below normal. Hyponatremia may occur in patients with heart failure or ‘Syndrome of Inappropriate Antidiuretic Hormone Secretion’ (SIADH), which is a condition where the body retains too much water. Excessively low sodium levels may result in difficulties in concentration and memory, or in maintaining your balance. In serious cases, brain swelling and seizures might occur.
Tolvaptan may also be used with other medications, such as a diuretic (a medication which helps to remove excess water and salt from the body), to reduce the amount of water in your body.
Tolvaptan works by blocking vasopressin, a hormone that reduces water loss from the body. With increased urine production, excess water is removed and sodium levels in the blood will increase.
If you forget to take a dose, take it as soon as you remember. Then take your next dose at the usual time. Do not take two doses to make up for the missed dose
Inform your healthcare professional if:
Very rarely, Tolvaptan may cause injury to the liver. Symptoms of liver problems include: Dark brown urine, light coloured stools (pale grey/ clay coloured), nausea, vomiting, loss of appetite, yellowing of skin or eyes
Tolvaptan may also cause severe dehydration, if left untreated. Symptoms of dehydration include: Dark yellow and strong-smelling urine, reduced urination, unusual tiredness, feeling dizzy or light-headed or dry mouth, lips, eyes or skin
Lastly, the symptoms of a drug allergy include one or more of the following:
If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately
Avoid taking grapefruit and grapefruit juice when you are taking this medication as these may interact with your medication and increase the risk of side-effects.
Some medications may interact with Tolvaptan and affect their effectiveness or increase the risk of side-effects. However, these medications may also be important for your treatment. Inform your healthcare professional of any medications you are currently taking. Examples include:
Consult your healthcare professional if you are unsure whether your existing medications can be taken together with this medication.
Store in a cool and dry place, away from direct sunlight. Keep this medication away from children.
Pack this medication into a black trash bag and seal it tightly before throwing into the rubbish chute or bin.
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 May 2023
This article was last reviewed on Thursday, August 31, 2023