Patient leaflet - Tolvaptan Zentiva 15 mg tablets
1. WHAT TOLVAPTAN ZENTIVA IS AND WHAT IT IS USED FOR
This medicine contains the active substance tolvaptan, which belongs 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 Zentiva is 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 (hyponatremia). That can lead to difficulties in concentration and memory, or in keeping your balance.
2. WHAT YOU NEED TO KNOW BEFORE YOU TAKE TOLVAPTAN ZENTIVA
Do not take Tolvaptan Zentiva 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 (“hypernatremia”)
- 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 before taking Tolvaptan Zentiva if you:
- cannot drink enough water or if you are fluid restricted
- have difficulties 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 other ingredients of this medicine (listed in section 6)
- suffer from kidney disease called autosomal dominant polycystic kidney disease (ADPKD)
- have diabetes
Drinking enough water
Tolvaptan Zentiva causes water loss because it increases 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 Zentiva is not suitable for children and adolescents (under age 18).
Other medicines and Tolvaptan Zentiva
Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines, including medicines obtained without a prescription. The following medicines may increase the effect of Tolvaptan Zentiva:
- 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 contains large amount of salt. The following medicines may lower the effect of Tolvaptan Zentiva:
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.
Tolvaptan Zentiva may increase the effect of the following medicines:
- digoxin (used for treatment of irregularities of heart beat 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).
Tolvaptan Zentiva 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 Zentiva together. Your doctor will be able to decide what is suitable for you.
Tolvaptan Zentiva with food and drink
Avoid drinking grapefruit juice when taking Tolvaptan Zentiva.
Pregnancy, breast-feeding and fertility
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 Tolvaptan Zentiva.
Driving and using machines
Tolvaptan Zentiva is 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 short period.
Tolvaptan Zentiva contains lactose and sodium
If you have been told by your doctor that you have an intolerance to some sugars, contact your doctor before taking this medicine.
This medicine contains less than 1mmol sodium (23 mg) per tablet, that is to say essentially ‘sodium-free’.
3. HOW TO TAKE TOLVAPTAN ZENTIVA
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 Zentiva will be initiated in hospital.
- For treatment of your low sodium (hyponatremia), your doctor will start with a dose of 15 mg and may then increase it to a maximum of 60 mg to achieve the desired level of serum sodium. To monitor the effects of Tolvaptan Zentiva 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 7.5 mg.
- Swallow the tablet 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 Zentiva 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 Zentiva
If you forget to take your medicine, you should take the dose as soon as you remember on the same day. If you do not take your tablets on one day, take your normal dose on the next day. Do not take a double dose to make up for a forgotten doses.
If you stop taking Tolvaptan Zentiva
If you stop taking Tolvaptan Zentiva this may lead to reoccurrence of your low sodium. Therefore, you should only stop taking this medicine 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. Serious side effects:
If you notice any of the following side effects, you may need urgent medical attention. Stop taking Tolvaptan Zentiva 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 level 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 (frequency 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 the 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 ZENTIVA
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 blister after EXP. The expiry date refers to the last day of that month. 7.5 mg tablets:
Store in the original package in order to protect from light.
15 mg and 30 mg tablets:
Do 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 Zentiva contains
The active substance is tolvaptan.
Each Tolvaptan Zentiva 7.5 mg tablet contains 7.5 mg tolvaptan.
Each Tolvaptan Zentiva 15 mg tablet contains 15 mg tolvaptan.
Each Tolvaptan Zentiva 30 mg tablet contains 30 mg tolvaptan.
- The other ingredients are lactose monohydrate, cellulose microcrystalline, croscarmellose sodium, povidone, magnesium stearate.
What Tolvaptan Zentiva looks like and contents of the pack
The different strengths of Tolvaptan Zentiva tablets have different shapes and embossing:
Tolvaptan Zentiva 7.5 mg tablets: White to off white, round, flat bevelled edge, 5.5 mm tablets with marking “C5” debossed one side.
Tolvaptan Zentiva 15 mg tablets: White to off white, triangular, flat, bevelled edge 6.1 x 5.7 mm tablets with marking “C6” debossed on one side. Tolvaptan Zentiva 30 mg tablets: White to off white, round, flat, bevelled edge 7.5 mm tablets with marking “C7” debossed on one side.
Tolvaptan Zentiva 7.5 mg are available as 10 × 1 tablet in Alu/PVC/Alu/OPA perforated unit dose blisters
Tolvaptan Zentiva 15 mg and 30 mg are available as 10 × 1 tablet in Alu/PVC/Alu/OPA perforated unit dose blisters
Not all pack sizes may be marketed.
Marketing Authorisation Holder:
Zentiva Pharma UK Limited,
12 New Fetter Lane,
London, EC4A 1JP,
United Kingdom
Manufacturer:
Coripharma ehf.
Reykjavikurvegur 78-80,
IS-220 Hafnarfjordur,
Iceland
This leaflet was last updated in June 2025
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