Tolvaptan 7.5 mg tablets – patient leaflet, side effects, dosage

1. What Tolvaptan tablets are and what they are used for

Tolvaptan tablets, which contain the active substance tolvaptan, belong to a group of medicines called vasopressin antagonists. Vasopressin is a hormone that helps prevent the loss of water from the body by reducing urine output. Antagonist means that it prevents vasopressin having its effect on water retention. This leads to a reduction in the amount of water in the body by increasing urine production and as a result it increases the level or concentration of sodium in your blood.

Tolvaptan tablets are used to treat low serum sodium levels in adults. You have been prescribed this medicine because you have a lowered sodium level in your blood as a result of a disease called “syndrome of inappropriate antidiuretic hormone secretion” (SIADH) where the kidneys retain too much water. This disease causes an inappropriate production of the hormone vasopressin which has caused the sodium levels in your blood to get too low (hyponatraemia). That can lead to difficulties in concentration and memory, or in keeping your balance.

2. What you need to know before you take Tolvaptan tablets

Do not take Tolvaptan tablets if:

• you are allergic to tolvaptan or any of the other ingredients of this medicine (listed in section 6) or if you are allergic to benzazepine or benzazepine derivatives (e.g. benazepril, conivaptan, fenoldopam mesylate or mirtazapine)
• your kidneys do not work (no urine production)
• you have a condition which increases the salt in your blood (“hypernatraemia”)
• you have a condition which is associated with a very low blood volume
• you do not realise when you are thirsty
• you are pregnant
• you are breast-feeding.

Warnings and precautions

Talk to your doctor or pharmacist before taking Tolvaptan tablets if you:

• cannot drink enough water or if you are fluid restricted
• have difficulties in urination or have an enlarged prostate
• suffer from liver disease
• had an allergic reaction in the past to benzazepine, tolvaptan or other benzazepine derivatives (e.g. benazepril, conivaptan, fenoldopam mesylate or mirtazapine), or to any of the other ingredients of this medicine (listed in section 6)
• suffer from a kidney disease called autosomal dominant polycystic kidney disease (ADPKD)
• have diabetes.

Drinking enough water

Tolvaptan tablets cause water loss because they increase your urine production. This water loss may result in side effects such as dry mouth and thirst or even more severe side effects like kidney problems (see section 4). It is therefore important that you have access to water and that you are able to drink sufficient amounts when you feel thirsty.

Children and adolescents

Tolvaptan tablets are not suitable for children and adolescents (under age 18).

Other medicines and Tolvaptan tablets

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines. This includes all medicines obtained without a prescription.

The following medicines may increase the effect of this medicine:

• ketoconazole (against fungal infections)
• macrolide antibiotics
• diltiazem (treatment for high blood pressure and chest pain)
• other products which increase the salt in your blood or which contain large amounts of salt.

The following medicines may lower the effect of this medicine:

• barbiturates (used to treat epilepsy/seizures and some sleep disorders)
• rifampicin (against tuberculosis)
• St. John’s wort, a herbal medicinal product used to treat depression.

This medicine may increase the effect of the following medicines:

• digoxin (used for treatment of irregularities of heartbeat and heart failure)
• dabigatran etexilate (used to thin the blood)
• metformin (used to treat diabetes)
• sulfasalazine (used to treat inflammatory bowel disease or rheumatoid arthritis).

This medicine may lower the effect of the following medicines:

• desmopressin (used to increase blood clotting factors).

It may still be alright for you to take these medicines and Tolvaptan tablets together. Your doctor will be able to decide what is suitable for you.

Tolvaptan tablets with food and drink

Avoid drinking grapefruit juice when taking Tolvaptan tablets.

Pregnancy and breast-feeding

If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.

Do not take this medicine if you are pregnant or breast-feeding.

Adequate contraceptive measures must be used during use of this medicine.

Driving and using machines

Tolvaptan tablets are unlikely to adversely affect your ability to drive or to operate machinery. However, you may occasionally feel dizzy or weak or you may faint for a short period.

Tolvaptan tablets contain lactose

If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicine.

3. How to take Tolvaptan tablets

Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure.

• Treatment with Tolvaptan tablets will be initiated in hospital
• For treatment of your low sodium (hyponatraemia), your doctor will start with a dose of 15mg and may then increase it to a maximum of 60mg to achieve the desired level of serum sodium. To monitor the effect of Tolvaptan tablets your doctor will do regular blood tests. To achieve the desired level of serum sodium your doctor can give in some instances a lower dose of 7.5mg
• Swallow the tablets without chewing, with a glass of water
• Take the tablets once a day preferably in the morning with or without food.

If you take more Tolvaptan tablets than you should

If you have taken more tablets than your prescribed dose, drink plenty of water and contact your doctor or your local hospital immediately. Remember to take the medicine pack with you so that it is clear what you have taken.

If you forget to take Tolvaptan tablets

If you forget to take your medicine, you have to take the dose as soon as you remember on the same day. If you do not take your tablet on one day, take your normal dose on the next day. Do not take a double dose to make up for a forgotten dose.

240 mm

If you stop taking Tolvaptan tablets

If you stop taking Tolvaptan tablets this may lead to reoccurrence of your low sodium. Therefore, you should only stop taking Tolvaptan tablets if you notice side effects requiring urgent medical attention (see section 4) or if your doctor tells you to.

If you have any further questions on the use of this medicine, ask your doctor or pharmacist.

4. Possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.

If you notice any of the following side effects, you may need urgent medical attention. Stop taking Tolvaptan tablets and immediately contact a doctor or go to the nearest hospital if you:

• find it difficult to urinate
• find a swelling of the face, lips or tongue, itching, generalised rash, or severe wheezing or breathlessness (symptoms of an allergic reaction).

Consult your doctor if symptoms of fatigue, loss of appetite, right upper abdominal discomfort, dark urine or jaundice (yellowing of skin or eyes) occur.

Other side effects

Very common (may affect more than 1 in 10 people):

• feeling sick
• thirst
• rapid rise in levels of sodium.

Common (may affect up to 1 in 10 people):

• excessive drinking of water
• water loss
• high levels of sodium, potassium, creatinine, uric acid and blood sugar
• decrease in level of blood sugar
• decreased appetite
• fainting
• headache
• dizziness
• low blood pressure when standing up
• constipation
• diarrhoea
• dry mouth
• patchy bleeding in the skin
• itching
• increased need to urinate, or to urinate more frequently
• tiredness, general weakness
• fever
• general feeling of being unwell
• blood in urine
• raised levels of liver enzymes in the blood
• raised levels of creatinine in the blood.

Uncommon (may affect up to 1 in 100 people):

• sense of taste altered
• kidney problems.

Not known (cannot be estimated from the available data):

• allergic reactions (see above)
• liver problems
• acute liver failure (ALF)
• increase in liver enzymes.

Reporting of side effects

If you get any side effects, talk to your doctor, pharmacist, or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via Yellow Card Scheme

Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine.

5. How to store Tolvaptan tablets

Keep this medicine out of the sight and reach of children.

Do not use this medicine after the expiry date which is stated on the carton and on each blister after EXP. The expiry date refers to the last day of that month.

This medicinal product does not require any special storage conditions.

Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.

6. Contents of the pack and other information

What Tolvaptan tablets contain

• The active substance is tolvaptan.

  Each Tolvaptan 7.5mg tablet contains 7.5mg tolvaptan.

  Each Tolvaptan 15mg tablet contains 15mg tolvaptan.

  Each Tolvaptan 30mg tablet contains 30mg tolvaptan.

• The other ingredients are lactose monohydrate, maize starch, microcrystalline cellulose, magnesium stearate, croscarmellose sodium, hydroxypropylcellulose, indigo carmine aluminium lake (E132).

What Tolvaptan tablets look like and contents of the pack

Tolvaptan 7.5mg tablets: Light blue to blue coloured, round, biconvex, uncoated tablets, debossed with "MT" on one side and "18" on other side with approximate dimension of 5.0 mm, free from physical defects. Tolvaptan 15mg tablets: Light blue to blue coloured, triangle, biconvex, uncoated tablets, debossed with '"MT" on one side and "7" on other side with approximate dimensions of 6.7 x 6.3 x 3.3 mm, free from physical defects. Tolvaptan 30mg tablets: Light blue to blue coloured, round, biconvex, uncoated tablets, debossed with "MT" on one side and "8" on other side with approximate dimension of 8.1 mm, free from physical defects.

Tolvaptan tablets are available as 7, 10, 28, 30 and 56 tablets in PVC/Alu blisters and/or 7x1, 10x1, 28x1, 30x1, 56x1 tablets in perforated unit dose PVC/Alu blisters in a carton.

Not all pack sizes may be marketed.

Marketing Authorisation Holder

Accord Healthcare Limited

Sage House, 319 Pinner Road

North Harrow, Middlesex

HA1 4HF

United Kingdom

Manufacturers

Accord Healthcare Limited

Sage House, 319 Pinner Road,

North Harrow, Middlesex

HA1 4HF, United Kingdom

Pharmadox Healthcare Limited

KW20A Kordin Industrial Park,

Paola PLA 3000, Malta

Accord-UK Ltd

Whiddon Valley

Barnstaple

Devon

EX32 8NS

This leaflet was last revised in November 2025.

If you would like a leaflet with larger text, please contact

01271 385257