Samsca Side Effects

Generic name: tolvaptan

Medically reviewed by Drugs.com. Last updated on Jan 26, 2025.

Note: This document provides detailed information about Samsca Side Effects associated with tolvaptan. Some dosage forms listed on this page may not apply specifically to the brand name Samsca.

Applies to tolvaptan: oral tablet.

Important warnings This medicine can cause some serious health issues

Oral route (tablet)

Samsca® should be initiated and re-initiated in patients only in a hospital where serum sodium can be monitored closely.

Too-rapid correction of hyponatremia (eg, greater than 12 mEq/L/24 hours) can cause osmotic demyelination resulting in dysarthria, mutism, dysphagia, lethargy, affective changes, spastic quadriparesis, seizures, coma, and death.

Slower rates of correction may be advisable in susceptible patients (eg, those with severe malnutrition, alcoholism, or advanced liver disease).Samsca® Not For Use For Autosomal Dominant Polycystic Kidney Disease (ADPKD): Because of the risk of hepatoxicity, tolvaptan should not be used for ADPKD outside of the FDA-approved REMS.

Oral route (tablet)

Warning: Risk Of Serious Liver Injury:Jynarque(TM) (tolvaptan) can cause serious and potentially fatal liver injury.

Acute liver failure requiring liver transplantation has been reported.Measure ALT, AST and bilirubin before initiating treatment, at 2 weeks and 4 weeks after initiation, then monthly for the first 18 months and every 3 months thereafter.

Prompt action in response to laboratory abnormalities, signs, or symptoms indicative of hepatic injury can mitigate, but not eliminate, the risk of serious hepatotoxicity.Because of the risks of serious liver injury, Jynarque(TM) is available only through a restricted distribution program under a Risk Evaluation and Mitigation Strategy (REMS) called the Jynarque(TM) REMS Program.

Precautions

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly and to decide if you should continue to use it. Blood tests may be needed to check for unwanted effects.

You should not use tolvaptan (the active ingredient contained in Samsca) together with clarithromycin (Biaxin®), indinavir (Crixivan®), itraconazole (Sporanox®), ketoconazole (Nizoral®), nefazodone (Serzone®), nelfinavir (Viracept®), ritonavir (Norvir®), saquinavir (Fortovase®, Invirase®), or telithromycin (Ketek®). Using these medicines together may increase risk for more serious side effects.

Check with your doctor right away if you have drowsiness, confusion, mood changes, muscle weakness in the arms or legs, seizures (convulsions), or trouble with speaking, swallowing, or controlling body movements. These may be symptoms of a serious and rare condition called osmotic demyelination syndrome (ODS). This may occur if the sodium blood level rises too fast.

Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.

Certain medicines or illnesses, such as vomiting or diarrhea, may cause you to lose too much body water (dehydration). If you think you are dehydrated, tell your doctor right away. Always have water available to drink if you are thirsty, unless your doctor tells you otherwise.

Ask your doctor first before you use any medicine or salt substitutes that contain potassium.

You should not eat grapefruit or drink grapefruit juice while you are using this medicine. Grapefruit or grapefruit juice may increase the effects of tolvaptan in your body.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (eg, St. John's wort) or vitamin supplements.

Serious side effects of Samsca

Along with its needed effects, tolvaptan may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking tolvaptan:

More common side effects

• blurred vision
• dry mouth
• flushed, dry skin
• frequent urination
• fruit-like breath odor
• increased hunger
• increased thirst
• increased urination
• increased volume of pale, dilute urine
• nausea
• stomach pain
• sweating
• thirst
• troubled breathing
• unexplained weight loss
• unusual tiredness or weakness
• vomiting

Less common side effects

• anxiety
• blood in the urine
• bloody stools
• blue lips, fingernails, or skin
• bruising
• chest pain
• confusion
• cough
• coughing or vomiting blood
• dark urine
• dizziness or lightheadedness
• fainting
• fast, slow, irregular, or shallow heartbeat
• fever
• irregular, fast or slow, or shallow breathing
• loss of consciousness
• muscle cramp, spasm, pain, or stiffness
• pain, redness, or swelling in the arm or leg
• persistent bleeding or oozing from puncture sites, mouth, or nose
• pink or red urine
• rash
• rectal bleeding
• stomach tenderness
• troubled breathing
• sweating
• vaginal bleeding

Incidence not known

• difficulty swallowing
• general feeling of tiredness or weakness
• headache
• high blood pressure
• hives, itching, skin rash
• irritability
• light-colored stools
• muscle twitching
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• restlessness
• seizures
• stomach pain, continuing
• swelling of the feet or lower legs
• tightness in the chest
• yellow eyes or skin

Other side effects of Samsca

Some side effects of tolvaptan may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common side effects

• difficulty having a bowel movement
• lack or loss of strength

Less common side effects

• loss of appetite
• weight loss

For healthcare professionals

Applies to tolvaptan: oral kit, oral tablet.

General adverse events

The most frequently reported side effects included thirst, dry mouth (up to 13%), asthenia, constipation, pollakiuria or polyuria and hyperglycemia.^[Ref]

Gastrointestinal

• Very common (10% or more): Dry mouth (up to 13%), nausea, dysgeusia
• Common (1% to 10%): Constipation, ischemic colitis, gastrointestinal bleeding, diarrhea^[Ref]

Cardiovascular

• Common (1% to 10%): Intracardiac thrombus, ventricular fibrillation, orthostatic hypotension, syncope^[Ref]

Genitourinary

• Common (1% to 10%): Blood in urine
• Uncommon (0.1% to 1%): Urethral hemorrhage, vaginal hemorrhage^[Ref]

Hematologic

• Common (1% to 10%): Prolonged prothrombin time, disseminated intravascular coagulation^[Ref]

Musculoskeletal

• Common (1% to 10%): Rhabdomyolysis, arthralgia, myalgia

Nervous system

• Common (1% to 10%): Cerebrovascular accident, syncope, dizziness, headache
• Uncommon (0.1% to 1%): Dysgeusia
• Postmarketing reports: Osmotic demyelination syndrome^[Ref]

Renal

• Very common (10% or more): Pollakiuria and polyuria (11%)
• Uncommon (0.1% to 1%): Renal impairment^[Ref]

Respiratory

• Common (1% to 10%): Pulmonary embolism, respiratory failure^[Ref]

Metabolic

• Common (1% to 10%): Hyperglycemia, anorexia, diabetic ketoacidosis, dehydration, hyperkalemia, decreased appetite, creatinine increased, hypernatremia, hypoglycemia, hyperuricemia, weight gain^[Ref]

Dermatologic

• Common (1% to 10%): Ecchymosis, pruritus, dry skin, urticaria
• Uncommon (0.1% to 1%): Pruritic rash^[Ref]

Hepatic

• Common: Alanine aminotransferase increased, aspartate aminotransferase increased, bilirubin increased

Hypersensitivity

• Postmarketing reports: Hypersensitivity reactions including anaphylactic shock and generalized rash

Other

• Very common (10% or more): Thirst (up to 18%)
• Common (1% to 10%): Asthenia, pyrexia, malaise

See also:

Frequently asked questions

• What is the difference between Jynarque (tolvaptan) and Samsca (tolvaptan)?

Further information

Samsca side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer