Cilosta

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Cilosta

Medically reviewed

Marina Burgos

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Cilosta

Cilosta is a trade name for the medication containing the active ingredient Cilostazol (INN), a synthetic organic compound specifically developed as a selective phosphodiesterase 3 (PDE3) inhibitor. It is prescribed for systemic delivery and is taken as a single-ingredient, solid oral tablet.

Property Description
Active ingredient Cilostazol
Form Oral Tablet
Pharmacological class Selective PDE3 Inhibitor; Antiplatelet Agent
Common use Symptom reduction in conditions causing restricted circulation
Origin Synthetic organic compound

What Pharmacological Class Does Cilostazol Belong To?

Cilostazol's core identity is its classification as a Selective Phosphodiesterase 3 (PDE3) Inhibitor, a feature that distinguishes it from many older circulatory agents. This mechanism results in a dual physiological effect: it acts as a vasodilator by promoting the relaxation of arterial smooth muscle and functions as an antiplatelet agent by reducing the tendency of platelets to aggregate. Cilostazol’s mechanism enhances blood flow and inhibits platelet activation. This supports the conclusion that the medication effectively helps to sustain and improve circulation by maintaining wider vessels and preventing clot formation.


Cilosta: Form and Composition

Cilosta is prepared for patients exclusively as an oral tablet, the standardized dosage form for this therapy. The tablet's composition is a monotherapy, consisting solely of the active therapeutic compound, Cilostazol. This compound is combined with necessary, inactive pharmaceutical excipients (such as binders and fillers) to create a stable, standardized formulation designed for reliable absorption following the oral route of administration.

Regulatory References

  1. NIH DailyMed

What side effects are possible with Cilosta?

Possible Side Effects and Safety Information: Cilosta

Cilosta (cilostazol) is a medication primarily used to treat the symptoms of intermittent claudication, a form of peripheral artery disease (PAD). While generally well-tolerated, it is important for patients to be aware of potential side effects and safety considerations.


Common Side Effects

The most frequently reported side effects are usually mild and may lessen over time. These often relate to the drug's mechanism of action as a platelet aggregation inhibitor and vasodilator.

Side Effect Category Examples
Cardiovascular Headache, palpitations, peripheral edema (swelling)
Gastrointestinal Diarrhea, abnormal stools, dyspepsia (indigestion)
Other Dizziness, rhinitis (runny nose)

Serious Side Effects and Warnings

A boxed warning is included for patients with heart failure of any severity, as cilostazol may increase the risk of mortality in this population. Patients with a history of serious cardiac conditions should discuss risks thoroughly with their healthcare provider.

Cilosta should not be used in patients with:

  • Congestive heart failure (CHF)
  • Any condition predisposing to bleeding (e.g., active peptic ulcer, proliferative diabetic retinopathy)
  • Known hypersensitivity to the drug or any of its components

Because of its antiplatelet effects, there is an increased risk of bleeding (e.g., bruising, nosebleeds). Patients should inform their doctor immediately if they experience signs of serious bleeding or symptoms such as fever, persistent sore throat, or unusual tiredness, as these could indicate a blood disorder. Close monitoring is necessary when co-administered with other antiplatelet or anticoagulant agents.

Overdose and Emergency Response

A documented overdose of Cilosta (Cilostazol) is anticipated to present with an exaggeration of its pharmacological effects. Official regulatory documents list key clinical manifestations, including severe headache, persistent diarrhea, and significant effects on the cardiovascular system such as a fall in blood pressure (hypotension) and an increase in heart rate (tachycardia), alongside the possible occurrence of cardiac arrhythmias.

In the event of a suspected overdose, immediate medical attention must be sought. Official patient guidance requires contacting emergency services immediately if the affected individual collapses, has a seizure, experiences trouble breathing, or cannot be awakened.

Management procedures described in regulatory labeling emphasize careful observation of the patient and the use of supportive treatment. Due to the high plasma protein binding of Cilostazol (95% to 98%), the official documentation notes that blood purification methods such as hemodialysis and peritoneal dialysis are unlikely to be efficient for drug removal.

Furthermore, the official profile includes statements on serious outcomes documented in post-marketing reports, such as severe hemorrhagic events or cardiac complications like Torsades de pointes and QTc prolongation. These severe cardiac events were predominantly observed in individuals with pre-existing cardiac disorders.

Therapeutic Uses of Cilosta

What Cilosta Treats: Main Uses and Benefits

Cilosta is applied in contexts involving certain distressing symptoms related to physical discomfort associated with poor blood flow to the lower limbs, a condition known as intermittent claudication. The medication is used to help manage symptomatic manifestations, specifically painful cramping, aching, or fatigue in the leg muscles that occurs during activity and is relieved by rest.

The medication is considered relevant for easing symptomatic manifestations of Peripheral Artery Disease (PAD) and is applied across domains where additional symptomatic support is needed. It provides support that helps ease the overall symptom burden and contributes to improving day-to-day comfort during symptomatic periods.

The medication is applied when symptoms create noticeable interference with daily stability, and may assist with maintaining functional stability. The support offered contributes to patients coping more steadily with symptom fluctuations during periods of physical activity. This provides supportive relief when symptoms interfere with routine activities.


Key Focus: Symptom relief for leg discomfort

Cilosta is applied in contexts involving certain distressing symptoms in conditions characterized by periods of heightened symptoms, and is commonly used when short-term symptomatic assistance is needed.

Regulatory References

  1. NIH MedlinePlus overview on Cilostazol

Eligibility and Restrictions for Use

Who Can and Cannot Use Cilostazol

Official regulatory information outlines specific patient populations for whom the use of Cilostazol is prohibited (contraindicated) or restricted.


Contraindicated Populations (Must NOT Be Used)

Condition / Population Status
Heart Failure (of any severity) Contraindicated
Active Bleeding / Bleeding Risk Contraindicated (e.g., active peptic ulceration, recent hemorrhagic stroke, proliferative diabetic retinopathy)
Severe Organ Impairment Contraindicated (Severe renal impairment, Moderate or Severe hepatic impairment)
Recent CV Event (EMA) Contraindicated (Unstable angina, MI, or coronary intervention within 6 months)
Pregnancy Contraindicated / Not Recommended

Restricted & Special Populations

  • Pediatric Use: Safety and effectiveness have not been established in pediatric patients.
  • Breastfeeding: Not recommended; a decision to discontinue nursing or discontinue the drug is advised.
  • Drug Interactions: A mandatory dose reduction (e.g., 50 mg twice daily) is required when co-administered with strong or moderate inhibitors of CYP3A4 or CYP2C19 (e.g., erythromycin, omeprazole).

What should I know about interactions with other medicines?

Cilosta has officially documented interactions that may require dose adjustment or result in contraindications when co-administered with certain medicines or products.

Pharmacodynamic and Hemostatic Interactions

Cilosta is contraindicated in patients who are simultaneously receiving two or more additional antiplatelet or anticoagulant agents, such as acetylsalicylic acid (ASA/Aspirin), clopidogrel, warfarin, or heparin, due to the increased risk of hemorrhage. Caution is advised when co-administering with only one antiplatelet or anticoagulant agent, or with any other agent that may reduce blood pressure, as additive effects are possible.

Metabolic and Pharmacokinetic Interactions

Cilosta is metabolized by liver enzymes, primarily CYP3A4 and, to a lesser extent, CYP2C19. Co-administration with strong or moderate inhibitors of these enzymes increases the exposure and pharmacological activity of Cilosta and its active metabolites.

Interacting Product Category Example Medicines Regulatory Constraint
Strong/Moderate CYP3A4 Inhibitors Erythromycin, Diltiazem, Ketoconazole Reduce Cilosta dose to 50 mg twice daily.
CYP2C19 Inhibitors Omeprazole Reduce Cilosta dose to 50 mg twice daily.

Consumption of Grapefruit Juice is restricted because it is an inhibitor of intestinal CYP3A4, which can also increase Cilosta plasma concentrations.

Mechanism of Action

The mechanism of action for Cilostazol is defined by its selective inhibition of the enzyme Phosphodiesterase Type 3 ( PDE3), which is present in both vascular smooth muscle cells and circulating platelets. By acting as a competitive inhibitor, Cilostazol prevents PDE3 from breaking down the key cellular messenger, cyclic AMP (cAMP), leading to a rapid increase in cAMP levels across these affected cells.

This cAMP surge activates the Protein Kinase A ( PKA) signaling pathway, which results in the drug's dual physiological consequences. In the arterial smooth muscle, the cascade inhibits the contraction mechanism, leading to vasodilation (artery widening). Concurrently, in circulating platelets, the high cAMP level suppresses the activation of key adhesion receptors, producing a measurable antiplatelet effect that modulates clotting potential. The mechanistic activity is constrained by PDE3 expression in the myocardium, where cAMP increase can induce cAMP-dependent positive chronotropic and inotropic effects.

Dosage and Administration Information

How to Use Cilosta (Cilostazol) — Administration Guidelines

This section outlines the standardized usage instructions for Cilostazol.

Administration Details

Attribute Instruction
Route of Administration Oral. The tablet must be swallowed whole.
Standard Dosing Schedule 100 mg taken twice daily (e.g., morning and evening).
Timing in Relation to Meals Must be taken on an empty stomach. This means at least 30 minutes before or 2 hours after a meal (e.g., breakfast and the evening meal).

Special Conditions and Adjustments

Mandatory Dose Reduction

If you are taking certain medications that inhibit specific liver enzymes (CYP3A4 or CYP2C19 inhibitors, such as certain antifungals or acid reducers), the required dose is 50 mg twice daily. This adjustment is necessary to prevent high drug levels.

Missed Dose Protocol

If a dose is missed, take it as soon as you remember. However, if it is almost time for the next scheduled dose, skip the missed dose and resume your regular schedule. Do not take a double dose to make up for the missed one.

Treatment Duration and Evaluation

The full effect of Cilostazol may not be observed for several weeks. Treatment effectiveness must be formally re-evaluated by a healthcare provider after 3 months. If no improvement is observed by this time, the medication should be discontinued.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Cilosta (Cilostazol)


Evidence for Use in Symptom Relief for Intermittent Claudication

The main research exploring Cilostazol was studied for its use in conditions related to restricted circulation in the lower limbs, known as intermittent claudication. This area was primarily studied through multiple large Randomized Controlled Trials (RCTs). These studies compared people randomly assigned to receive either Cilostazol or a placebo, over defined time intervals. Research examined outcomes related to physical discomfort, specifically by monitoring changes in a patient's walking ability. Key measurements were the Initial Claudication Distance (ICD) and the Absolute Claudication Distance (ACD). Studies report measurements where the change in both the ICD and ACD was compared between the groups receiving Cilostazol and the placebo groups over the study period.

Evidence from Trials on Vascular Outcomes (Restenosis Prevention)

Research also explored Cilostazol in patients who have undergone specific procedures to improve blood flow, such as angioplasty. These studies examined outcomes following these procedures. Research examined vessel re-narrowing, known as restenosis (re-narrowing of the treated vessel segment), and the incidence of needing repeat procedures. Some trials described patterns where the reported rates of repeat revascularization procedures (TLR) were tracked between the groups receiving Cilostazol and the control groups.


Long-Term Study Data and Durability of Response

Most core studies had follow-up durations were limited, typically to three to six months. Because the controlled trials had limited follow-up, there is limited information for long-term outcomes, meaning the durability of observed changes over many years is not fully established.

What is Still Uncertain or Not Yet Fully Studied

The primary limitation noted is the short duration of the pivotal trials, which means that long-term effects are not fully established regarding major cardiovascular events and mortality. Furthermore, studies explored the impact on patient-reported Quality of Life (QoL), but the findings were mixed, making the certainty surrounding the consistency of this outcome low. Comparative evidence is lacking against other treatments, and the research provides context but not individual predictions.

Key Studies & References

  1. Systematic review and meta-analysis of randomized clinical trials appraising the impact of cilostazol after percutaneous coronary intervention

Frequently Asked Questions (FAQ)

Common questions about Cilosta (FAQ)

Q: Does Cilosta cure the underlying blood vessel condition it is prescribed for?

According to official product information, Cilosta is used to help manage the symptoms of intermittent claudication. It works by improving blood flow, which in turn helps to decrease discomfort and increase walking distance. The medication is described as a treatment for symptoms, not as a cure for the underlying vascular condition.

Q: Is it typical to not see any improvement during the first month of taking Cilosta?

Clinical information indicates that while some individuals may begin to notice symptomatic relief within 2 to 4 weeks, it can take up to 12 weeks to achieve the full therapeutic effect. Therefore, not seeing immediate improvement during the first month may be an expected possibility. Regulatory guidance suggests a formal re-evaluation of treatment effectiveness after 3 months.

Q: Is it possible for Cilosta to cause low blood pressure (hypotension)?

Yes, the official documentation lists low blood pressure, known as hypotension, as a possible cardiovascular side effect of Cilosta.

Q: Why are regular blood tests sometimes necessary while on Cilosta therapy?

Regulatory information states that blood tests are recommended periodically to monitor the levels of white blood cells and platelets. This monitoring is done to check for the rare possibility of serious hematologic abnormalities, such as leukopenia (low white cells) or thrombocytopenia (low platelets).

Q: Can Cilosta potentially cause an increased risk of infection due to its effects on the body?

Yes, official sources list infection as a common adverse event. This is because the drug has been reported to temporarily lower white blood cell counts, which can potentially increase the chance of getting an infection.

Q: Is abdominal pain a frequently reported side effect of Cilosta?

Yes, abdominal pain is listed in the official documents as a common side effect of the medication. This symptom was reported by 1% to 10% of patients in clinical trials.

Q: What types of bleeding are listed as serious adverse events requiring immediate attention?

Signs of serious bleeding listed in official warnings include the presence of bloody or black/tarry stools, blood in the urine, or vomiting blood or material that looks like coffee grounds. Postmarketing reports have also included intracranial hemorrhage (bleeding in the brain).

Q: How does Cilosta differ from other commonly used antiplatelet or circulatory drugs?

Cilosta is specifically classified as a selective Phosphodiesterase Type 3 ( PDE3) inhibitor. This mechanism provides a dual effect, acting both to widen blood vessels (vasodilation) and to reduce the tendency of platelets to clot (antiplatelet effect). Its antiplatelet effect is noted to be reversible and resolves more quickly upon discontinuation than certain other antiplatelet agents.

Q: Have official sources mentioned any warnings regarding Cilosta and blood cell counts?

Yes, official sources mention a risk of rare but serious hematologic abnormalities. These include conditions such as leukopenia (low white cell count), thrombocytopenia (low platelet count), and in very rare cases, aplastic anemia.

Q: What are the reported signs of a serious allergic reaction to Cilosta?

Official documents state that signs of a serious allergic reaction, or hypersensitivity, may include swelling of the face, lips, tongue, or throat, hives, or a skin rash. Hypersensitivity to the drug is listed as a contraindication.

Q: Does smoking tobacco affect the way Cilosta works in the body?

Clinical trial analyses showed that the benefits of the drug were observed regardless of a patient's smoking status. However, smoking tobacco may generally worsen the underlying vascular condition being treated.

Q: Is Cilosta available in a generic version?

Yes, the active ingredient in Cilosta is Cilostazol, which is generally available in generic form.

Q: Is Cilosta an over-the-counter (OTC) medication?

No, the official status of Cilosta ( Cilostazol) is that it is a prescription-only medication and is not available over the counter.

Q: What is the official guidance on stopping Cilosta treatment suddenly?

Official guidance recommends discontinuation if a patient shows no clinical improvement after 3 months of therapy. Due to its antiplatelet effect, official summaries also recommend stopping the medication 3 to 5 days prior to any planned elective surgical procedures.

Q: Are there specific safety considerations or guidelines for older adults taking Cilosta?

Pharmacokinetic studies have not shown significant differences in how the drug is processed in older patients compared to younger patients. However, as with many medications, greater sensitivity in some older individuals cannot be entirely ruled out.

Q: Are there different brand names for Cilosta used in various countries?

Cilosta is a trade name for the active ingredient Cilostazol. This ingredient is sold under various other brand names in different regions, such as Pletal.

Q: Are there any official warnings about Cilosta affecting a person's ability to drive or use machinery?

Yes, official product information advises caution regarding driving or operating machinery. This warning is in place because the medication has the potential to cause dizziness, which may affect coordination or reaction time.

Q: What non-directive steps are recommended if a patient experiences dizziness or lightheadedness on Cilosta?

If a person experiences dizziness or lightheadedness, patient information mentions that sitting up or standing slowly may help reduce the risk of dizzy or fainting spells.

Q: Is it necessary to inform a healthcare team about taking Cilosta before any planned surgery?

Yes, due to its antiplatelet effect and the potential for increased bleeding, it is necessary to inform the healthcare team about taking Cilosta before any surgical procedure. Official guidance recommends the medication be stopped 3 to 5 days prior to elective surgery.

Q: How is the antiplatelet effect of Cilosta described compared to other platelet inhibitors?

Its antiplatelet effects are described as being reversible. They resolve more quickly upon discontinuation, typically within 3 to 5 days, compared to certain other antiplatelet agents like aspirin or clopidogrel.

Q: How are the risks of overdose with Cilosta generally described in medical literature?

Medical literature describes the potential symptoms of an overdose, which may include a severe headache, dizziness, fainting, diarrhea, or a fast or irregular heartbeat.

Q: Is a transient feeling of nausea common when beginning Cilosta treatment?

Yes, nausea is listed in clinical trial summaries as a common adverse event associated with the medication, reported by 5% or more of patients.

Q: Are there any reported cases of Cilosta causing muscle pain or cramps?

Yes, official sources list muscle pain as a possible side effect of the medication.

How should Cilosta be stored and disposed of?

Storage and Protection Requirements

Cilostazol tablets must be stored at Controlled Room Temperature, specifically between 20^circ to 25 C (68^circ to 77 F), with excursions permitted up to 30 C. The container should be kept tightly closed and stored away from excess heat and moisture; the medication must not be frozen. The tablets should remain in their original container and be protected from light. As a mandated safety measure, the medication must be stored out of the sight and reach of children.

Disposal Instructions

Regulatory guidance advises consulting a pharmacist for instructions on disposing of unused or expired tablets. If a drug take-back program is unavailable, official recommendations state that the medicine should be mixed with an undesirable substance, such as dirt or used coffee grounds, placed in a sealed bag or container, and then thrown into the household trash.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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