Tvaptan 15 Tablet 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). Additionally, Tvaptan 15 Tablet is also used to treat autosomal dominant polycystic kidney disease (ADPKD).
 
Tvaptan 15 Tablet 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 Tvaptan 15 Tablet 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 Tvaptan 15 Tablet if you are pregnant as it may cause foetal harm. Consult your doctor before taking Tvaptan 15 Tablet if you are breastfeeding. Tvaptan 15 Tablet is not recommended for children below 18 years as the efficacy and safety have not been established. Tvaptan 15 Tablet 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.

Tvaptan 15 Tablet belongs to a group of medicines called vasopressin V2 receptor antagonist. Tvaptan 15 Tablet 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, Tvaptan 15 Tablet is also used to treat autosomal dominant polycystic kidney disease (ADPKD). Tvaptan 15 Tablet 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, Tvaptan 15 Tablet slows down the development of cysts in kidneys and reduces the symptoms of the disease. Tvaptan 15 Tablet antagonises the effect of vasopressin; this results in an increase in free water clearance and decreases urine osmolality due to increased urinary excretion, thereby increasing serum sodium concentrations.

• Dizziness
• Headache
• Dry mouth
• Fatigue
• Weakness
• Diarrhoea
• Thirst
• Increased urge to urinate

Do not take Tvaptan 15 Tablet 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 Tvaptan 15 Tablet if you are pregnant as it may cause foetal harm. Consult your doctor before taking Tvaptan 15 Tablet if you are breastfeeding. Tvaptan 15 Tablet is not recommended for children below 18 years as efficacy and safety have not been established. Tvaptan 15 Tablet may cause dizziness, so drive with caution. Avoid consuming alcohol as it might cause increased dizziness. 

Drug-Drug Interaction:  Inform the doctor if you are taking antibiotics (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 Tvaptan 15 Tablet. 

Drug-Disease Interaction: Inform the doctor if you have liver disease, difficulty in urination, diabetes, high levels of uric acid or kidney disease.

• CLARITHROMYCIN
• TELITHROMYCIN
• SULPHAMETHOXAZOLE+TRIMETHOPRIM
• KETOCONAZOLE
• ITRACONAZOLE
• RITONAVIR
• INDINAVIR
• SAQUINAVIR
• NELFINAVIR
• NEFAZODONE
• SPIRONOLACTONE
• VALSARTAN
• SACUBITRIL
• HEPARIN

• 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.

• Regular monitoring of liver functioning and electrolyte levels while taking Tvaptan 15 Tablet is advised.
• Treatment with Tvaptan 15 Tablet 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.

Hyponatremia: Sodium is an important electrolyte that helps in maintaining water balance in and around the cells. It helps in proper nerve and 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 milliequivalent 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.