pentastarch

Action and Spectrum

Actions and Spectrum: 

pentastarch is a synthetic colloid solution used in medical settings for intravenous fluid replacement and resuscitation. It is a type of hydroxyethyl starch (HES) and is classified as a plasma expander. pentastarch molecules are derived from the natural substance starch but are modified to have different properties and characteristics. 

Action:  

pentastarch works by increasing the oncotic pressure of the blood, which helps to retain fluid within the blood vessels and avert fluid from leaking into surrounding tissues. This effect is achieved by the large molecular weight of pentastarch, which makes it less likely to be filtered through the kidneys into the urine. As a result, it remains in the bloodstream for a longer duration compared to crystalloid solutions like saline. 

When administered intravenously, pentastarch can help increase blood volume and improve tissue perfusion, making it beneficial for treating hypovolemia (low blood volume) and shock due to various causes, including hemorrhage, trauma, surgery, or severe dehydration. 

Spectrum:  

The spectrum of pentastarch refers to its range of molecular sizes. pentastarch is named “penta-” because it consists of five different molecular weight fractions. Each fraction has a specific size range, providing various properties that affect its safety and pharmacokinetics. 

pentastarch with a broader spectrum of molecular weights is believed to have more balanced effects on coagulation, renal function, and tissue distribution compared to other types of hydroxyethyl starch solutions. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Pruritus 

Elevated serum amylase 

Severe anaphylactic reactions 

Fluid overload 

Black Box Warning

Black Box Warning: 

None 

Contraindication / Caution

Contraindication/Caution: 

Contraindication 

• Anaphylactic reactions: pentastarch should not be administered to individuals who have a known allergy or hypersensitivity to hydroxyethyl starch or any of its components. Anaphylactic reactions can be severe and life-threatening in such cases. 
• Renal impairment: Patients with severe renal impairment/acute kidney injury are at an enhanced risk of further renal damage when given pentastarch. This is due to the potential accumulation of the starch molecules in the kidneys, which can lead to kidney dysfunction. 
• Coagulopathy: pentastarch can interfere with the coagulation system, leading to bleeding complications. Therefore, it should be avoided in patients with known coagulopathy or bleeding disorders. 
• Severe dehydration: pentastarch is not suitable for initial resuscitation in cases of severe dehydration, especially if there is no adequate blood volume expansion. 
• Congestive heart failure: pentastarch may worsen fluid overload and increase the workload on the heart in patients with congestive heart failure. 
• Severe liver disease: Patients with severe liver dysfunction may have impaired metabolism and clearance of pentastarch, leading to potential adverse effects. 
• Sepsis: The use of HES solutions, including pentastarch, has been associated with an increased risk of adverse outcomes in patients with sepsis. Therefore, its use in this population is generally discouraged. 
• Critically ill patients: In critically ill patients, especially those with sepsis, trauma, or multiple organ failure, pentastarch may not provide additional benefits compared to other fluid resuscitation options and may even increase the risk of adverse events. 

Caution 

• Allergic reactions: Although rare, hypersensitivity reactions, including anaphylaxis, can occur with the use of pentastarch. Healthcare providers should be prepared to manage any allergic reactions promptly, and the solution should not be given to patients with a known allergy to hydroxyethyl starch or any of its components. 
• Renal impairment: pentastarch is associated with an increased risk of kidney injury, especially in patients with pre-existing renal impairment. It should be used cautiously in patients with compromised renal function, and alternative fluid options may be considered in such cases. 
• Coagulopathy: pentastarch can interfere with the coagulation system, potentially leading to bleeding complications.  
• Dose and duration: pentastarch should be used at the little effective dose and for the lower duration necessary to achieve the desired clinical effect. Prolonged use or excessive dosing can increase the risk of adverse events. 
• Monitoring: Patients receiving pentastarch should be closely monitored for signs of fluid overload, renal function, coagulation parameters, and electrolyte imbalances. Regular assessments can help detect and manage any potential complications promptly. 
• Cardiovascular conditions: pentastarch may exacerbate fluid overload in patients with congestive heart failure/other cardiovascular conditions. Caution should be exercised when administering this solution to such patients. 
• Volume overload: pentastarch is a plasma expander and can cause volume expansion. It should be used cautiously in patients susceptible to fluid overload, such as those with severe liver disease or pulmonary edema. 
• Geriatric and pediatric patients: Elderly and pediatric patients may have different pharmacokinetics and may be more susceptible to adverse effects. Careful dosing adjustments and monitoring are crucial in these populations. 
• Use in specific populations: The safety and efficacy of pentastarch in pregnant and breastfeeding women, as well as in patients with specific medical conditions, may not be well-established. Caution is advised when using pentastarch in these populations, and alternative treatment options should be considered when possible. 
• Risk-benefit assessment: The use of pentastarch should always involve a thorough risk-benefit assessment by healthcare professionals. In some cases, alternative fluid resuscitation options, such as crystalloids, may be preferred due to their safety profile. 

Pregnancy / Lactation

Pharmacology

Pregnancy consideration:  

US FDA pregnancy category: Not assigned. 

Lactation:   

Excreted into human milk: Not known. 

Pregnancy category: 

• Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester. 
• Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 
• Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    
• Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    
• Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    
• Category N: There is no data available for the drug under this category. 

Adminstartion

Pharmacology: 

pentastarch is a synthetic colloid solution used as an intravenous plasma expander in medical settings. It is composed of five different molecular weight fractions of hydroxyethyl starch, derived from natural starch but modified for improved properties.

When administered intravenously, pentastarch increases the oncotic pressure of the blood, leading to fluid retention within the blood vessels and improved tissue perfusion.

This effect is achieved by the large molecular weight of pentastarch, which prolongs its presence in the bloodstream compared to crystalloid solutions. 

Pharmacodynamics: 

Mechanism of action: The action of pentastarch lies in its ability to function as a plasma expander when administered intravenously. As a synthetic colloid solution, pentastarch is designed to increase the oncotic pressure of the blood, thereby facilitating fluid retention within the blood vessels. This effect is achieved due to the unique properties of pentastarch molecules: 

• Molecular Size: pentastarch consists of five different molecular weight fractions of hydroxyethyl starch, derived from natural starch. The large molecular size of pentastarch prevents it from diffusing freely across the blood vessel walls into the interstitial space, keeping it predominantly within the intravascular compartment. 
• Osmotic Effect: The high molecular weight of pentastarch exerts an osmotic effect, drawing water from the interstitial space into the bloodstream. This increases the blood volume and, consequently, the venous return to the heart. 
• Increased Fluid Retention: By increasing the oncotic pressure within the blood vessels, pentastarch helps retain fluid within the circulatory system. This effect can be beneficial in cases of hypovolemia (low blood volume) due to conditions like hemorrhage, trauma, surgery, severe dehydration, or shock. 
• Improved Tissue Perfusion: The increased blood volume and improved venous return resulting from pentastarch administration lead to enhanced tissue perfusion, allowing vital organs to receive an enough supply of oxygen and nutrients. 

Pharmacokinetics: 

Absorption 

pentastarch is administered intravenously, bypassing the gastrointestinal tract and, therefore, the process of absorption. Upon infusion, it enters the bloodstream directly. 

Distribution 

Once in the bloodstream, pentastarch remains in the intravascular compartment, exerting its plasma-expanding effects. Due to its relatively larger molecular size, it does not promptly diffuse into the interstitial fluid, staying mainly within the blood vessels. 

Metabolism 

pentastarch is not metabolized by the body. It is a synthetic compound derived from starch and has been modified to resist enzymatic degradation by amylases in the body. As a result, its pharmacokinetics are characterized by a prolonged presence in the bloodstream compared to natural starch. 

Elimination and Excretion 

pentastarch is primarily eliminated from the body by renal excretion. The kidneys filter the pentastarch molecules from the blood and excrete them into the urine. The larger molecular weight fractions of pentastarch can lead to reduced renal clearance, which is one of the concerns associated with HES solutions, including pentastarch. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: pentastarch 

Why do we use pentastarch? 

pentastarch is a type of synthetic colloid solution used in medical settings for various purposes. Its primary use is as an intravenous fluid replacement and resuscitation agent.  

• Volume expansion and fluid replacement: pentastarch is used to increase blood volume and intravascular fluid levels in cases of hypovolemia (low blood volume). This can occur due to conditions like hemorrhage, trauma, surgery, severe dehydration, or other fluid loss situations. 
• Hemodynamic support: pentastarch can help stabilize blood pressure and improve tissue perfusion in critically ill patients, including those with shock or sepsis. 
• Management of hypotension: In certain clinical scenarios where fluid resuscitation with crystalloids alone is inadequate, pentastarch may be used to achieve rapid hemodynamic stabilization. 
• Perioperative fluid management: pentastarch may be utilized in surgical settings to maintain adequate intravascular volume and support cardiovascular function during procedures. 
• Plasma expander during anesthesia: pentastarch is commonly used during general anesthesia to prevent hypotension and maintain cardiovascular stability. 
• Preoperative fasting: pentastarch may be administered preoperatively to patients undergoing elective surgery to prevent dehydration and stabilize blood pressure before anesthesia induction. 
• Plasma volume substitution in plasma exchange procedures: pentastarch can be used as a substitute for plasma in therapeutic plasma exchange treatments.