Trastocir

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Trastocir

Medically reviewed

Laura Arias

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 Trastocir

Trastocir is a prescription-only medication that addresses circulatory issues by promoting better blood flow in the arteries. Its active substance, Cilostazol, is a synthetic compound provided for oral administration as a tablet.

Property Description
Active ingredient Cilostazol
Form Tablet
Pharmacological class Phosphodiesterase III (PDE3) Inhibitor
Common use Improving peripheral circulation
Origin Synthetic quinolinone derivative

What Type of Medicine is Trastocir (Cilostazol)?

Trastocir belongs to the major pharmacological class known as phosphodiesterase III (PDE3) inhibitors, a mechanism clinically recognized for its role in regulating vascular function. The active ingredient, Cilostazol, is a synthetic quinolinone derivative. This substance is a dual-action drug, also classified as both a potent vasodilator and a platelet-aggregation inhibitor. The medication is a single-ingredient product, containing only Cilostazol alongside the necessary pharmaceutical excipients that form the tablet.

Dual Action and General Purpose of Trastocir

The general purpose of Trastocir is to promote improved blood flow and prevent obstructions within the circulatory system. This makes it a standard therapeutic agent for adults experiencing discomfort due to reduced blood supply to their limbs. The therapeutic outcome is achieved through the compound's dual mechanism of action. Cilostazol inhibits PDE3 activity, leading to inhibition of platelet aggregation and vasodilation. For the patient, this means the drug works by simultaneously widening blood vessels to increase capacity and reducing the "stickiness" of platelets to keep the blood flowing smoothly, thereby enhancing the overall efficiency of blood movement.

Regulatory References

  1. NIH DailyMed Label for Cilostazol
  2. MedlinePlus Drug Information: Cilostazol
  3. FDA Labeling for Cilostazol

What side effects are possible with Trastocir?

Possible Side Effects and Safety Information

The official safety profile for Trastocir (Cilostazol) details adverse reactions classified by frequency and the body system affected. These classifications reflect how government regulatory documents organize and communicate the medicine’s safety profile.


Frequency-Classified Adverse Reactions

Adverse effects are categorized based on their documented occurrence rates in clinical use:

  • Very Common (ge 1/10): The most frequently reported effects include Headache and Diarrhea, which are often noted to occur more commonly during the initial stages of therapy.
  • Common (ge 1/100 to < 1/10): This category includes Dizziness, Insomnia, Palpitations, Tachycardia, Nausea, Vomiting, and Peripheral Oedema.
  • Uncommon (ge 1/1,000 to < 1/100): Less frequent documented reactions include Angina Pectoris, Myocardial Infarction, and Stroke.

Safety Restrictions and Serious Reactions

The regulatory label explicitly defines critical limitations for use. Trastocir is contraindicated in patients with congestive heart failure of any severity. It is also restricted in individuals with severe renal impairment or moderate to severe hepatic impairment.

Serious adverse reactions documented in regulatory sources include the potential for severe haemorrhage (due to the drug's antiplatelet activity) and rare but serious blood dyscrasias, such as Aplastic Anaemia. These safety constraints establish the official limitations and critical risks associated with the medicine.

Overdose and Emergency Response

Overdose and When to Seek Help

Official Overdose Manifestations

The regulatory profile for Trastocir (Cilostazol) overdose indicates that symptoms are an exaggeration of the drug's intended pharmacological effects, primarily impacting the cardiovascular system. Documented clinical manifestations include a fast or irregular heartbeat (tachycardia, tachyarrhythmia), a substantial fall in blood pressure (hypotension), severe headache, and dizziness. Gastrointestinal symptoms such as vomiting and severe diarrhea are also noted in official labeling. Because of the potential for profound hypotension and severe tachyarrhythmia, the overdose is officially classified as carrying a risk of cardiovascular instability.

Regulatory Mandates for Emergency Action

Regulatory authorities stress that any suspected overdose requires immediate medical attention. Individuals must contact emergency services or a Poison Control center without delay. Management is strictly symptomatic and supportive because official documents state that no specific antidote is known for Cilostazol. Medical professionals may consider procedures such as gastric lavage or the administration of activated charcoal to reduce absorption. Continuous monitoring of vital signs and cardiac function is necessary for observation and management.

Therapeutic Uses of Trastocir

Main Therapeutic Uses

Trastocir is a targeted biological therapy indicated for the treatment of specific types of cancer that demonstrate an overproduction of a protein called human epidermal growth factor receptor 2 (HER2). This protein, when found in high amounts on the surface of cancer cells, signals the cells to grow and divide more rapidly than normal.

Breast Cancer

Trastocir is used in the management of HER2-positive breast cancer across different stages of the disease:

  • Early-Stage Breast Cancer: It is used following primary treatments such as surgery, chemotherapy, or radiotherapy to reduce the risk of the cancer returning.
  • Metastatic Breast Cancer: In cases where the cancer has spread beyond the original site, Trastocir is used to slow the progression of the disease. It may be administered as a standalone therapy or in combination with other oncology treatments.

Gastric Cancer

Trastocir is also indicated for patients with HER2-positive metastatic gastric (stomach) cancer or gastroesophageal junction cancer. In these cases, it is typically used in combination with chemotherapy to target the HER2-expressing malignant cells.

Mechanism of Action and Benefits

Unlike traditional chemotherapy, which affects all rapidly dividing cells, Trastocir is designed to recognize and attach specifically to the HER2 receptors on the surface of cancer cells.

Targeted Action

By binding to these receptors, the medication works to:

  • Inhibit Cell Signaling: It blocks the signals that tell the cancer cells to grow and proliferate.
  • Immune System Activation: It may assist the body's immune system in identifying and destroying the marked cancer cells.
  • Suppression of Tumor Growth: The primary clinical goal of treatment is to shrink existing tumors or prevent the further spread of the disease, thereby improving clinical outcomes for patients with HER2-overexpressing malignancies.

Regulatory References

  1. NIH MedlinePlus overview

Eligibility and Restrictions for Use

Who Can and Cannot Use Trastocir?

The official criteria for using Trastocir (trastuzumab) are strictly based on laboratory findings and the patient's existing physiological condition, as defined in regulatory documents.

Populations for Whom Use is Allowed

Treatment is limited to adult patients (generally ge18 years of age) whose tumor has been confirmed to overexpress the HER2 protein or exhibit HER2 gene amplification, typically by an FDA-approved diagnostic test. Treatment is not suitable for patients who are HER2-negative.

Populations for Whom Use is Contraindicated or Restricted

Trastocir is contraindicated for use in patients with a known hypersensitivity to the drug substance, murine proteins, or any of its excipients. It is also contraindicated in patients with severe dyspnoea at rest due to advanced malignancy complications or those requiring supplemental oxygen therapy.

Use is restricted in patients with certain cardiac conditions. Before and during treatment, cardiac function, specifically the Left Ventricular Ejection Fraction (LVEF), must be assessed and must be within acceptable limits. The medicine must be withheld or discontinued for clinically significant decreases in LVEF or symptomatic heart failure. Due to the risk of fetal harm, use is not recommended in pregnant or breastfeeding individuals. Females of reproductive potential must use effective contraception during treatment and for a specified period after the final dose.

What should I know about interactions with other medicines?

The official regulatory profile for Trastocir (Cilostazol) documents interactions that primarily involve enzyme metabolism and additive pharmacodynamic effects.

Pharmacokinetic Interactions (Exposure Risk)

Trastocir is metabolized by the cytochrome P450 enzymes CYP3A4 and CYP2C19. Co-administration with inhibitors of these enzymes increases the plasma concentration (exposure) of Cilostazol and/or its active metabolites, which may necessitate specific regulatory constraints.

Inhibitor Category Example Medicines Listed in Labeling
Strong/Moderate CYP3A4 Ketoconazole, Itraconazole, Erythromycin, Diltiazem
CYP2C19 Omeprazole, Ticlopidine

Pharmacodynamic Interactions

Co-administration with other agents that inhibit platelet aggregation or blood coagulation carries an additive risk of bleeding events, due to Trastocir's inherent effect on platelet function. Medicines subject to this consideration include Aspirin, Clopidogrel, and Warfarin.

Interaction-Related Constraints and Restrictions

  • Contraindicated Disease State: The drug is absolutely contraindicated in patients with Heart Failure of any severity, a restriction mandated due to documented risks associated with the drug's pharmacological class.
  • Food/Substance Timing: Official labeling requires administration on an empty stomach (e.g., 30 minutes before or 2 hours after a meal) because food significantly increases the drug's maximum plasma concentration. Grapefruit juice is documented to have a similar effect on drug exposure.

Mechanism of Action

Targeting Phosphodiesterase 3 (PDE3) and cAMP Signaling

Trastocir functions as a selective inhibitor of the enzyme Phosphodiesterase 3 (PDE3), which degrades the secondary messenger molecule cyclic adenosine monophosphate (cAMP) inside vascular smooth muscle cells and platelets. This molecular action elevates intracellular cAMP concentrations, triggering two primary physiological consequences: vascular smooth muscle relaxation and inhibition of platelet aggregation.


Modulating Vascular Relaxation and Perfusion

Increased cAMP within the blood vessel walls initiates a signaling cascade that causes the smooth muscle fibers to relax, resulting in vasodilation (vessel widening). This mechanism, focused on modulating peripheral vascular tone, is necessary for decreasing resistance to blood flow and increasing regional blood perfusion.


Influencing Platelet Activity

Concurrently, the elevated cAMP acts within platelets as an inhibitory signal, decreasing their responsiveness to factors that promote activation and adhesion. This action decreases the rate of platelet aggregation, thereby influencing the rheological properties and flow dynamics of blood within the circulatory system.

Dosage and Administration Information

How to Use Trastocir

Trastocir is provided for oral use as a tablet and is typically initiated by healthcare professionals experienced in peripheral artery disease management. The usage principles for this medication are established based on clinical protocols, focusing on precise dosing, frequency, and administration timing.

Standard Administration Protocol

The standard prescribed adult regimen is 100 mg taken twice daily. For patients concurrently using certain medications that may inhibit drug metabolism, clinical guidelines indicate a dose reduction to 50 mg taken twice daily.

Instruction Category Clinical Usage Guideline
Route of Administration Oral (taken by mouth).
Standard Daily Dosing 100 mg twice daily.
Timing Relative to Food Take on an empty stomach: 30 minutes before or 2 hours after breakfast and the evening meal.

Treatment Course and Assessment

The medication is used as part of a longer-term plan, and its effect is assessed over a defined period. While initial responses may be noted within two to four weeks, the clinical documentation specifies that the full beneficial effect of Trastocir may require up to 12 weeks of continuous use. Treatment should be discontinued if no improvement in symptoms is observed after a 3-month assessment period.

Population-Specific Use

Specific dosage adjustments are not typically required for older adults. Furthermore, no dosage change is needed for patients with mild hepatic impairment or those with renal impairment where creatinine clearance is greater than 25 mL/min.

Recent Clinical Evidence

Trastocir: Recent Clinical Evidence


Evidence Base for Symptomatic Intermittent Claudication

The primary research for Trastocir (Cilostazol) was evaluated in studies exploring symptoms of Intermittent Claudication (IC), a condition characterized by physical discomfort and functional limitations. The evidence base relies on multiple Randomized Controlled Trials (RCTs) and meta-analyses involving adults with IC. These studies focused on measuring outcomes reflecting daily functioning, such as Pain-Free Walking Distance (PFWD) and Maximal Walking Distance (MWD), primarily through standardized treadmill testing. Analyses of the data included descriptions of measured outcomes in functional metrics, contributing to the evidence being classified as Moderate for these endpoints.


Types of Studies and Measured Outcomes

The core studies typically featured follow-up durations that were limited to around 12 to 24 weeks. In addition to walking performance, studies monitored patient-reported outcomes describing perceived discomfort and quality-of-life (QoL) scores. Research also examined biomarker shifts, where data show patterns related to changes in some blood lipid levels (triglycerides and HDL cholesterol). Research was evaluated in specific patient groups, though subgroup findings are uncertain in some areas, as some studies described less pronounced patterns in older patients.


Long-Term Follow-up and Remaining Uncertainty

Long-term effects are not fully established because the foundational efficacy trials were short-term. Evidence is limited regarding the relationship between Trastocir and major outcomes such as the need for amputation or revascularization procedures. Similarly, certainty remains low on whether the medicine is associated with changes in the rate of cardiovascular events over the long term. The follow-up durations were limited, meaning comparative evidence is lacking for many important long-term comparisons.

Frequently Asked Questions (FAQ)

Common questions about Trastocir (FAQ)

Q: Is it safe to consume alcohol while a patient is using Trastocir?

Official product information does not explicitly list an interaction between Trastocir and alcohol. However, as with many medications, official sources generally advise caution regarding alcohol consumption while using the drug. The consideration of alcohol use is managed through discussions with a healthcare professional.

Q: Do patients need special monitoring or blood tests while on Trastocir?

Regulatory documents indicate that special monitoring is indicated during Trastocir use. This may include periodically checking a patient's platelet and white blood cell counts. Furthermore, official information notes that monitoring for specific cardiac symptoms or signs of a new systolic murmur may be performed.

Q: What happens in the body if Trastocir is stopped suddenly?

The official labeling does not describe an acute risk associated with sudden general discontinuation of the medicine. However, discontinuation is required if no improvement is seen after 3 months of use, or immediately if certain serious blood abnormalities are detected. Discontinuing treatment is a step that requires medical supervision.

Q: What types of foods or supplements should be avoided with Trastocir?

Official labeling advises against consuming grapefruit or grapefruit juice while using Trastocir. This restriction exists because grapefruit significantly increases the drug's plasma concentration in the body, which can be associated with increased side effects.

Q: Does Trastocir affect sleep?

The official product information lists Insomnia (difficulty sleeping) as a common adverse reaction reported in clinical trials. This effect is documented in the drug's safety profile.

Q: Is it normal to have stomach upset or diarrhea with Trastocir?

According to official safety information, Diarrhea is classified as a very common adverse reaction, meaning it is frequently reported in clinical studies. Other related common effects include Abdominal pain and Dyspepsia (indigestion or stomach discomfort).

Q: Is Trastocir meant to be taken long-term?

Treatment with Trastocir is often considered part of a longer-term strategy. Official documents require a patient assessment after the initial 3-month period to evaluate effectiveness. If beneficial effects are observed, the treatment may be continued, though regulatory documents do not specify a maximum duration.

Q: How will I know if Trastocir is actually helping?

The medicine is indicated for the reduction of symptoms associated with peripheral circulatory issues. The intended effect for patients is the observation of an increased walking distance without discomfort. This improvement is assessed clinically after approximately 3 months of continuous use.

Q: Do the initial side effects of Trastocir usually go away?

Official information notes that common effects like headache and diarrhea are frequently reported during the initial stages of therapy. However, the regulatory label does not guarantee that these initial side effects will always resolve completely over time.

Q: What kind of bleeding risk is associated with Trastocir?

Trastocir functions as a platelet aggregation inhibitor, which means it influences the blood's ability to clot. This action is associated with a general risk of bleeding events, including the potential for severe hemorrhage in rare cases. This safety risk is fully detailed in the official product information.

Q: Are there studies on Trastocir's use in different age groups?

Studies examining the drug's metabolism show that Trastocir clearance was not significantly different in patients between the ages of 50 and 80. This suggests that the drug's processing by the body is generally consistent across this adult age range.

Q: Does Trastocir help reduce the risk of future events related to the condition it treats?

Studies and regulatory reviews have concluded that there is limited or low certainty on the medicine’s association with long-term changes in the rate of major cardiovascular events. Trastocir is not described in official documents as a substitute for standard cardiovascular risk-reduction treatments.

Q: Can Trastocir lead to a fast or irregular heartbeat?

According to the safety profile, the medicine may induce or be associated with an increase in heart rate. Specific adverse reactions listed include a fast heartbeat (tachycardia), palpitations, and a form of irregular beat known as tachyarrhythmia.

Q: What is the difference between Trastocir and a true anticoagulant?

Trastocir is classified as a phosphodiesterase III inhibitor that primarily works as an antiplatelet agent to stop platelets from sticking together. This mechanism is distinct from a true anticoagulant, which works by targeting different blood clotting factors.

Q: Are there studies available that show the long-term safety profile of Trastocir?

Regulatory evidence states that the long-term effects of the medicine are not fully established. This is because the core efficacy trials used for regulatory approval were primarily short-term, lasting only 12 to 24 weeks.

Q: Does Trastocir affect the immune system?

The regulatory safety profile includes reports of rare but serious blood dyscrasias, such as agranulocytosis, and hypersensitivity reactions. These effects involve the body’s hematological and immune systems.

Q: Does Trastocir interact with blood pressure medications?

Trastocir is known to potentially cause low blood pressure (hypotension). Official guidance states that co-administration with other medications that already lower blood pressure presents a risk of an additive effect on blood pressure.

Q: Is Trastocir allowed during pregnancy or breastfeeding?

The regulatory label indicates against use during pregnancy due to potential risk of fetal harm suggested by animal studies. For breastfeeding, official information states it is unknown if the drug is excreted in human milk.

Q: What are the specific safety risks for older patients taking Trastocir?

Regulatory safety reviews have noted that in post-marketing use, many patients were older than those in initial trials. This observation may explain an increased reporting of side effects in the older population.

Q: Can a patient with a known bleeding condition use Trastocir?

Due to its effect on blood clotting, the regulatory label explicitly states that use of the medicine is restricted or contraindicated for patients with a hemostatic disorder or active pathologic bleeding.

Q: What are the signs of a serious problem that require immediate medical attention while taking Trastocir?

Official guidance emphasizes the reporting of signs of serious bleeding events. It is also important to report signs of rare blood disorders, such as an unexplained fever or persistent sore throat, as these require immediate medical evaluation.

Q: What is the main goal of treatment with Trastocir?

The main goal defined in official product information is the reduction of symptoms associated with peripheral circulatory issues. This objective is clinically measured by the patient's increased walking distance.

How should Trastocir be stored and disposed of?

How to Store and Dispose of Trastocir

Trastocir (Cilostazol) must be stored strictly according to regulatory guidelines to maintain its stability.

Storage Requirements

Condition Requirement
Temperature Store at Controlled Room Temperature, 20 C to 25 C (68 F to 77 F). Do not store above 30 C (86 F).
Protection Keep in the original container, tightly closed, protected from light and moisture.
Child Safety Keep out of the sight and reach of children.

Disposal Instructions

Unused, expired, or unwanted Trastocir must be handled according to local waste regulations. Do not flush the tablets down the toilet or pour them into a drain unless instructed to do so by an official disposal program. All waste must be disposed of in compliance with local regulations for pharmaceutical waste.

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

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