Tolvaptan
About
Tolvaptan belongs to a group of medicines called vasopressin V2 receptor antagonist used to treat hyponatremia (low levels of sodium) in patients with heart failure, liver disease and hormonal imbalances such as Syndrome of Inappropriate Antidiuretic Hormone (SIADH). Additionally, Tolvaptan is also used to treat autosomal dominant polycystic kidney disease (ADPKD).
Tolvaptan contains ‘tolvaptan’ that works by blocking the effect of vasopressin, resulting in decreased water reabsorption, a net increase in free water excretion (aquaresis) and an increase in serum sodium concentrations. This decrease in free water is not associated with an increased excretion of sodium or potassium ions, the increase in serum sodium concentration is solely a result of increased urine production
You are advised to take Tolvaptan for as long as your doctor has prescribed it for you depending on your medical condition. In some cases, you may experience certain common side-effects such as dizziness, headache, dry mouth, fatigue, diarrhoea, thirst and increased urge to urinate. Most of these side-effects do not require medical attention and will resolve gradually over time. However, you are advised to talk to your doctor if you experience these side-effects persistently.
Do not take Tolvaptan if you are pregnant as it may cause foetal harm. Consult your doctor before taking Tolvaptan if you are breastfeeding. Tolvaptan is not recommended for children below 18 years as the efficacy and safety have not been established. Tolvaptan may cause dizziness, so drive with caution. Avoid consuming alcohol as it might cause increased dizziness. Inform your doctor about all the medicines you are taking and about your health condition to rule out any unpleasant side-effects.
Uses of Tolvaptan
Medicinal Benefits
Tolvaptan belongs to a group of medicines called vasopressin V2 receptor antagonist. Tolvaptan is used to treat hyponatremia (low levels of sodium) in patients with heart failure, liver disease and hormonal imbalances such as Syndrome of Inappropriate Antidiuretic Hormone (SIADH). Besides this, Tolvaptan is also used to treat autosomal dominant polycystic kidney disease (ADPKD). Tolvaptan works by blocking the effect of vasopressin, a hormone which is involved in the formation of cysts in ADPKD patients. By blocking the effect of vasopressin, Tolvaptan slows down the development of cysts in kidneys and reduces the symptoms of the disease. Tolvaptan antagonises the effect of vasopressin, this results in an increase in free water clearance and decreases urine osmolality due to increased urinary excretion, thereby increases serum sodium concentrations.
Directions for Use
Storage
Side Effects of Tolvaptan
- Dizziness
- Headache
- Dry mouth
- Fatigue
- Weakness
- Diarrhoea
- Thirst
- Increased urge to urinate
In-Depth Precautions and Warning
Drug Warnings
Do not take Tolvaptan if you are allergic to any of its contents, if you have raised liver enzymes in the blood, very low blood volume, if there is no urine production, if you cannot tell that you are thirsty. Inform your doctor if you have liver disease, difficulty in urination, diabetes, high levels of uric acid, advanced kidney disease or if you have to restrict fluid intake due to certain medical conditions. Do not take Tolvaptan if you are pregnant as it may cause foetal harm. Consult your doctor before taking Tolvaptan if you are breastfeeding. Tolvaptan is not recommended for children below 18 years as efficacy and safety have not been established. Tolvaptan may cause dizziness, so drive with caution. Avoid consuming alcohol as it might cause increased dizziness.
Drug Interactions
Drug-Drug Interaction: Tolvaptan may interact with antibiotic (clarithromycin, telithromycin, sulfamethoxazole, trimethoprim), anti-fungal (ketoconazole, itraconazole), anti-HIV (ritonavir, indinavir, nelfinavir, saquinavir), antidepressant (nefazodone), aldosterone receptor antagonist (spironolactone), angiotensin receptor inhibitor (valsartan, sacubitril), blood thinner (heparin).
Drug-Food Interaction: Avoid consuming grapefruit juice and St. John’s wort (herbal supplement used to treat depression) while taking Tolvaptan.
Drug-Disease Interaction: Inform your doctor if you have liver disease, difficulty in urination, diabetes, high levels of uric acid or kidney disease.
Drug-Drug Interactions Checker List:
Safety Advice
Alcohol
unsafeAvoid consuming alcohol while taking Tolvaptan as it may cause increased dizziness.
Pregnancy
unsafeTolvaptan belongs to pregnancy category C. Tolvaptan is not recommended for use in pregnant women as it may cause foetal harm. Women of childbearing age must use effective contraception while taking Tolvaptan.
Breast Feeding
unsafeTolvaptan is not recommended for use in breastfeeding women. Consult your doctor if you are breastfeeding; your doctor will decide whether Tolvaptan can be taken by breastfeeding mothers or not.
Driving
cautionTolvaptan may cause dizziness, weakness and tiredness. Do not drive or operate heavy machinery if you feel dizzy.
Liver
cautionDose adjustment may be needed. Tolvaptan should be used with caution in patients with liver impairment/liver disease. Please consult your doctor if you have liver problems or any concerns regarding this.
Kidney
cautionTolvaptan should be used with caution in patients with kidney impairment/kidney disease. Please consult your doctor if you have kidney problems or any concerns regarding this.
Children
unsafeTolvaptan is not recommended for children below 18 years as efficacy and safety have not been established.
Habit Forming
Diet & Lifestyle Advise
- Eat a diet rich in whole grains, vegetables, and fruits.
- Avoid smoking and alcohol consumption.
- Maintain a healthy weight with proper diet and exercise.
- Manage stress with meditation, yoga, and massage.
- Drink plenty of fluids.
- Rehydration beverages that contain electrolytes are also helpful.
Special Advise
- Regular monitoring of liver functioning and electrolyte levels while taking Tolvaptan is advised.
- Treatment with Tolvaptan should be started and re-started in a hospital or in the presence of a healthcare professional to monitor the sodium levels in your blood closely.
Patients Concern
Disease/Condition Glossary
Hyponatremia: Sodium is an important electrolyte that helps in maintaining water balance in and around the cells. It helps in proper nerve, muscle functioning and maintains stable blood pressure levels. Low levels of sodium in the blood are referred to as hyponatremia. Normal levels of sodium are 135-145 milliequivalance per litre. Hyponatremia occurs when the level is below 135mEq/L. Symptoms include weakness, tiredness, nausea, vomiting, headache, irritability, confusion and muscle spasms.
Autosomal Dominant Polycystic Kidney Disease (ADPKD): It is an inherited disorder in which cysts are developed in the kidney. These cysts are non-cancerous sacs that contain a water-like fluid which puts pressure on the surrounding tissues, leading to reduced kidney function. Symptoms include high blood pressure, swollen abdomen, and back or side pain.
FAQs
Tolvaptan works by blocking the effect of vasopressin, a hormone which is involved in the formation of cysts in ADPKD patients. By blocking the effect of vasopressin, Tolvaptan slows down the development of cysts in kidneys, reduces the symptoms of the disease, and increases urine production. Thereby increases serum sodium concentrations.
Dry mouth could be a side-effect of Tolvaptan. Limiting caffeine intake, avoiding smoking and mouthwashes containing alcohol, drinking water regularly and chewing sugar-free gum/candy might help in stimulating saliva and thereby prevents drying of the mouth.
Diarrhoea could be a side-effect of Tolvaptan. Drink plenty of fluid to prevent dehydration if you experience diarrhoea. Consult your doctor if you have severe diarrhoea or if you find blood in stools.
Tolvaptan may cause the liver to not work properly. Consult your doctor immediately if you experience nausea, vomiting, fever, loss of appetite, abdominal pain, tiredness, dark urine, jaundice, itching and flu-like symptoms.
Tolvaptan may cause water loss due to increased urine production. This might result in side-effects such as thirst, dry mouth and kidney problems. To prevent this, drink plenty of water regularly. Drink 1-2 glasses of water before going to bed even though you are not thirsty. Special care must be taken in patients with diseases that might reduce fluid intake.
Consult your doctor before taking Tolvaptan if you are diabetic as Tolvaptan might increase the blood sugar levels. Regular monitoring of blood glucose levels while taking Tolvaptan is advised.
