Commonly reported side effects of cilostazol include: infection, change in stool, diarrhea, dizziness, headache, palpitations, and pharyngitis. Other side effects include: abdominal pain, peripheral edema, rhinitis, and tachycardia. See below for a comprehensive list of adverse effects.

Applies to cilostazol: oral tablet

Along with its needed effects, cilostazol 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 cilostazol:

More common

• Fast or irregular heartbeat
• fever

Less common

• Abnormal bleeding
• bloody or black tarry stools
• bruises or red spots on the skin
• fainting
• nausea, heartburn, or indigestion (severe or continuing)
• nosebleeds
• stiff neck
• stomach pain, cramping, or burning (severe)
• swelling of the tongue
• vomiting of blood or material that looks like coffee grounds

Incidence not known

• Bleeding gums
• bleeding tendency
• blistering, peeling, loosening of the skin
• blood in the urine or stools
• blurred vision
• chest pain
• chills
• clay-colored stools
• confusion
• cough or hoarseness
• coughing up blood
• dark urine
• diarrhea
• difficulty with breathing
• drowsiness
• fever with or without chills
• general feeling of tiredness or weakness
• headache, sudden and severe
• inability to speak
• itching of the eyes
• itching of the skin
• joint or muscle pain
• light-colored stools
• loss of appetite
• loss of consciousness
• lower back or side pain
• nausea and vomiting
• painful or difficult urination
• pinpoint red spots on the skin
• red skin lesions, often with a purple center
• red, irritated eyes
• seizures
• skin rash
• slurred speech
• sores, ulcers, or white spots on the lips or in the mouth
• stomach pain
• swollen glands
• temporary blindness
• unpleasant breath odor
• unusual bleeding or bruising
• unusual tiredness or weakness
• weakness in the arm or leg on one side of the body, sudden and severe
• weakness of part of the body
• yellow eyes or skin

Get emergency help immediately if any of the following symptoms of overdose occur while taking cilostazol:

Symptoms of overdose

• Dizziness or lightheadedness when getting up suddenly from a lying or sitting position

Some side effects of cilostazol 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

• Back pain
• dizziness
• gas
• headache
• increased cough
• pain or stiffness in the muscles
• pounding heartbeat
• runny or stuffy nose
• sore throat
• swelling of the arms or legs

Less common

• Bone pain
• burning feeling in the throat or chest
• difficulty with swallowing
• hives
• pain or stiffness in the joints
• ringing or buzzing in the ears
• swelling of the face, fingers, or lower legs

Incidence not known

• Bruising
• feeling of warmth
• pain
• redness of the face, neck, arms and occasionally, upper chest

Applies to cilostazol: oral tablet

The most frequent adverse reactions resulting in discontinuation of therapy were headache, palpitation, and diarrhea.

Very common (10% or more): Headache (up to 34%), dizziness (up to 10%)

Frequency not reported: Tinnitus

Postmarketing reports: Intracranial hemorrhage, cerebral hemorrhage, cerebrovascular accident, extradural hematoma, subdural hematoma

Very common (10% or more): Diarrhea (up to 19%), abnormal stools (up to 15%)

Common (1% to 10%): Dyspepsia, abdominal pain

Frequency not reported: Melena

Postmarketing reports: Gastrointestinal hemorrhage, vomiting, flatulence, nausea

Very common (10% or more): Infection (up to 14%)

Postmarketing reports: Anaphylaxis, angioedema, hypersensitivity

Very common (10% or more): Rhinitis (up to 12%), pharyngitis (up to 10%)

Frequency not reported: Epistaxis

Postmarketing reports: Pulmonary hemorrhage, interstitial pneumonia

Very common (10% or more): Palpitation (up to 10%)

Common (1% to 10%): Tachycardia

Frequency not reported: Atrial fibrillation, heart failure, myocardial infarction, nodal arrhythmia, supraventricular tachycardia, ventricular extrasystoles, ventricular tachycardia, left ventricular outflow obstruction

Postmarketing reports: Torsade de pointes, QTc prolongation, angina pectoris, hot flushes, blood pressure increased, subacute stent thrombosis, hypertension

Common (1% to 10%): Peripheral edema

Frequency not reported: Fever, generalized edema, malaise

Postmarketing reports: Pain, chest pain

Frequency not reported: Anorexia, hyperuricemia

Postmarketing reports: Blood glucose increased, blood uric acid increased

Frequency not reported: Conjunctivitis, retinal hemorrhage

Frequency not reported: Urticaria

Postmarketing reports: Subcutaneous hemorrhage, pruritus, skin eruptions, Stevens-Johnson syndrome, skin drug eruption, rash

Frequency not reported: Anemia

Postmarketing reports: Aplastic anemia, granulocytopenia, pancytopenia, bleeding tendency

Frequency not reported: Urinary frequency

Postmarketing reports: Hematuria

Frequency not reported: Creatinine increased

Postmarketing reports: BUN increased

Frequency not reported: Insomnia

Postmarketing reports: Hepatic dysfunction, abnormal liver function tests, jaundice