• Hyponatremia (Low sodium levels in the blood)
• Autosomal dominant polycystic kidney disease [ADPKD]

Tolvaptan blocks the vasopressin hormone effect (antidiuretic hormone- that helps to prevent water loss), decreases the amount of water in your body by increasing urine production, and, as a result, raises the concentration of sodium in your blood.

Inform your doctor including prescription, over-the-counter, nutritional or vitamin supplements, and herbal products. Certain medications may interact with Vaptan 15mg Tablet, reducing effectiveness by causing undesirable side effects. 

Inform your doctor if you have taken ketoconazole (against fungal infections), macrolide antibiotics, diltiazem (treatment for high blood pressure and chest pain), 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) it may increase the effect the drug whereas, drug-like barbiturates (used to treat epilepsy/seizures and some sleep disorders), rifampicin (against tuberculosis) and desmopressin may decrease the effect of the medicine. Avoid drinking grapefruit juice before or after the medication. It may interact with the drug.

• Protect from light and moisture
• Store at 25˚C
• Keep children away from the sight and reach of this medication.

Take a Vaptan 15mg Tablet exactly as directed by your doctor. Your doctor will provide the appropriate dose and frequency based on your medical condition and other factors. Do not crush or chew the tablets. Swallow the tablets whole with water. Have plenty of water and contact your doctor immediately. If you have taken an excess tablet than the prescribed dosage, don't double up the medicine if you forgot to take the medicine.

Side effects are unwanted symptoms caused by medicines. Even though all medicines cause side effects, not everyone gets them.

Serious

• Feeling difficulty in urination
• Allergic reaction (swelling in the face, lips, or tongue, itching, or severe wheezing or breathlessness)

Common

• Feeling sick
• Thirst
• A rapid rise in the level of sodium.
• 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
• Diarrhea
• Dry mouth
• Patchy bleeding in the skin
• Itching
• Frequent urination
• Tiredness, general weakness
• Fever
• Blood in urine
• Elevation of liver enzyme in the blood
• Raised levels of creatinine in the blood.

Consult your doctor if you have diabetes, liver, or kidney problems before starting the medicine. Drink plenty of water to overcome the water loss, and don't drink grape juice while under medication. Consult your doctor if you have lactose intolerance because the drug contains lactose. Inform your doctor if you can’t feel a sense of thirst. Individuals are advised to monitor their blood sodium levels to avoid undesirable side effects. Inform your doctor if you have the following symptoms: fatigue, loss of appetite, right upper abdominal discomfort, dark urine, or jaundice.

1. Otsuka Pharmaceutical Netherlands BV, Electronic medicines compendium (EMC), [Revised on Jan 2020], [Accessed on 21st Sep 2023] https://www.ema.europa.eu/en/documents/product-information/samsca-epar-product-information_en.pdf
2. Otsuka Pharmaceutical Co., Ltd, US Food and Drug Administration, [Revised on April 2013] https://www.accessdata.fda.gov/drugsatfda_docs/label/2013/022275s009lbl.pdf
3. KD Tripathi, Essentials of Medical Pharmacology, Adrenergic system and drugs, 7th edition, 2013, 134.
4. Goodman & Gilman’s, The Pharmacological Basis of Therapeutics, Blood coagulation and anticoagulant, fibrinolytic, and antiplatelet drugs, 12th edition, 2011, 866.