TENECTASE

Indications

• Acute myocardial infarction
• Acute coronary syndromes

Dosage

Adults: 30–50 mg (maximum per dose 50 mg), administered intravenously over 10 seconds, initiated within 6 hours of symptom onset.

Mechanism of action

Tenecteplase is a genetically engineered variant of tissue plasminogen activator (tPA) that binds to fibrin in a thrombus (blood clot) and activates plasminogen, converting it to plasmin. This process leads to the degradation of fibrin, thus facilitating the dissolution of the clot and restoration of normal blood flow.

Pharmacodynamics

The pharmacodynamic effects of tenecteplase include rapid thrombolysis in patients with acute myocardial infarction. The drug's fibrin specificity and longer half-life compared to alteplase contribute to its efficiency in dissolving clots. It enhances the body's ability to recanalize occluded coronary arteries, resulting in improved myocardial perfusion.

Pharmacokinetics

Tenecteplase is administered intravenously, with a bioavailability approaching 100%. The drug has a half-life of approximately 20 to 25 minutes, allowing for rapid action. Its clearance is primarily through the liver, and plasma levels can be affected by factors such as age, weight, and renal function. Monitoring is essential to ensure effective dosing and minimize the risk of bleeding complications.

Contra-indications

• Aortic stenosis
• Cardiac tamponade
• Head trauma
• Toxic pulmonary oedema
• Recent history of myocardial infarction
• Susceptibility to angle-closure glaucoma
• Ventilation and perfusion abnormalities

Adverse effects

• Drowsiness
• Hemiparesis
• Venous thrombosis
• Arrhythmias
• Asthenia
• Cerebral ischaemia
• Dizziness
• Flushing
• Headache
• Hypotension
• Nausea
• Vomiting
• Circulatory collapse
• Diarrhoea
• Skin reactions

Interactions

• Nitrates may develop tolerance leading to reduced therapeutic effects
• Care should be taken when used with other anticoagulants or antiplatelet agents

Precautions

• Caution in elderly patients due to potential for postural hypotension and falls
• Patients on long-acting nitrates should have doses adjusted to avoid tolerance
• Monitor for signs of bleeding

Pregnancy

Manufacturer advises caution, as risk cannot be ruled out.

Breast-feeding

Manufacturer advises avoiding breastfeeding for 24 hours after dose; express and discard milk during this time.

Storage

Store in a cool, dry place. Protect from light. Store vials in the original package until use.

Formulations

• Powder for solution for infusion

Indications

• Metabolic disorders
• Neurodegenerative diseases
• Cancer
• Cardiovascular diseases
• Inflammatory conditions

Dosage

Children: Refer to specific product guidelines or clinical protocols for accurate dosing information.

Adults: Refer to specific product guidelines or clinical protocols for accurate dosing information.

Mechanism of action

Activators generally work by binding to an enzyme or receptor, inducing a conformational change that increases its activity. For example, certain activators may enhance the binding affinity of substrates to enzymes, promote the phosphorylation of proteins in signaling pathways, or stabilize the active conformation of receptors, leading to amplified cellular responses.

Pharmacodynamics

The pharmacodynamics of activators involves their ability to modulate enzyme kinetics and receptor signaling. This can result in increased catalysis rates, enhanced cellular effects, or altered physiological responses. The therapeutic effect is often dose-dependent, with a balance needed to avoid overstimulation, which could lead to adverse effects.

Pharmacokinetics

The pharmacokinetics of activators can vary widely depending on their chemical structure and the target enzyme or receptor. Common parameters include absorption rate, distribution volume, metabolism pathways, and elimination half-life. Many activators may undergo hepatic metabolism before excretion, and their bioavailability can be influenced by factors such as formulation and route of administration.

Pregnancy

The safety of activators during pregnancy has not been well established. Consult with a healthcare provider for advice.

Breast-feeding

The effects of activators on breastfeeding infants are not well documented. Caution is advised.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Indications

• Thromboembolic disorders
• Acute myocardial infarction
• Ischemic stroke
• Deep vein thrombosis
• Pulmonary embolism

Dosage

Children: Refer to specific clinical guidelines or BNF for Children for dosing recommendations based on the condition being treated.

Adults: Refer to specific clinical guidelines or BNF for dosing recommendations based on the condition being treated.

Mechanism of action

Plasminogen is converted to plasmin by tissue plasminogen activator (tPA) and urokinase. Plasmin is a serine protease that cleaves fibrin, leading to the dissolution of blood clots. This process is critical in the maintenance of normal blood flow and is involved in various physiological and pathological processes, such as wound healing and thrombus resolution.

Pharmacodynamics

The pharmacodynamic effect of plasminogen is primarily related to its role in the fibrinolytic system. Its conversion to plasmin promotes the breakdown of fibrin, thereby facilitating the dissolution of clots. The activation of plasminogen can also influence other proteolytic pathways and modulate inflammatory responses. The balance between coagulation and fibrinolysis is essential for normal hemostasis.

Pharmacokinetics

Plasminogen is primarily synthesized in the liver and released into the bloodstream. It has a half-life of approximately 2 to 3 days. Plasminogen is distributed widely in body tissues and fluids, with a significant amount found in the plasma. Its metabolism occurs mainly in the liver, and it is cleared from the circulation by various receptors, including those on endothelial cells.

Contra-indications

• Active bleeding conditions
• Recent surgery
• Severe hypertension
• Known hypersensitivity to plasminogen or any of its components

Adverse effects

• Bleeding complications
• Allergic reactions
• Thrombosis
• Hypotension
• Headache
• Nausea

Interactions

• Anticoagulants may increase the risk of bleeding
• Antiplatelet agents may enhance bleeding risk
• Other thrombolytic agents may have additive effects

Precautions

• Monitor for signs of bleeding
• Use with caution in patients with liver or kidney impairment
• Assess for recent history of stroke or myocardial infarction

Pregnancy

Plasminogen should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus, as there are no adequate studies in pregnant women.

Breast-feeding

It is unknown if plasminogen is excreted in human milk; caution should be exercised when administering to nursing mothers.

Storage

Store at room temperature, away from light and moisture. Do not freeze.

Formulations

• Lyophilized powder for reconstitution

Indications

• Diabetes mellitus
• Chronic kidney disease-related anemia
• Hemophilia
• Cancer (as targeted therapy)
• Autoimmune diseases (e.g., rheumatoid arthritis)

Dosage

Children: Refer to specific product guidelines for dosing information.

Adults: Refer to specific product guidelines for dosing information.

Mechanism of action

Recombinant drugs function by mimicking the action of naturally occurring proteins in the body. For instance, recombinant insulin binds to insulin receptors on target tissues, facilitating glucose uptake and metabolism. Erythropoietin stimulates erythropoiesis by binding to erythropoietin receptors in the bone marrow, promoting the production of red blood cells.

Pharmacodynamics

The pharmacodynamics of recombinant drugs vary depending on the specific protein or hormone being replaced or supplemented. Generally, they exert their effects at the cellular level by interacting with specific receptors, leading to a cascade of biological responses. The therapeutic effects are usually dose-dependent and can vary based on the patient's biological response and the presence of antibodies against the recombinant product.

Pharmacokinetics

Pharmacokinetics of recombinant drugs include absorption, distribution, metabolism, and excretion (ADME) characteristics that can differ significantly based on the specific drug. Many recombinant proteins have a short half-life and require parenteral administration. They are typically distributed throughout the body via the bloodstream, metabolized by the liver and other tissues, and excreted primarily through the kidneys. The pharmacokinetics may be influenced by the patient's age, weight, and overall health.

Pregnancy

Recombinant proteins should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Caution is advised when administering recombinant proteins during breastfeeding, as the effects on the infant are not well established.

Storage

Store in a refrigerator at 2-8 degrees Celsius. Do not freeze, and protect from light.

Dosage

Children: Refer to specific clinical guidelines for doses relevant to tissue repair or related therapies in children, as there is no standard dosage for tissues.

Adults: Refer to specific clinical guidelines for doses relevant to tissue repair or related therapies, as there is no standard dosage for tissues.

Mechanism of action

Tissues do not have a single mechanism of action as drugs do. Instead, they function based on the interactions of various cell types and extracellular matrices. For example, muscle tissue contracts due to the interaction of actin and myosin filaments, while nervous tissue transmits signals through the action of neurotransmitters and ion channels.

Pharmacodynamics

The pharmacodynamics of tissues vary depending on the type of tissue and its specific function. For instance, muscle tissue's ability to contract involves the mechanisms of muscle excitation-contraction coupling, which includes changes in calcium ion concentrations and the role of ATP in muscle fiber contraction. Epithelial tissues have roles in absorption and secretion, influenced by transport mechanisms and junctions between cells. Connective tissues provide structural support and elasticity, which can be affected by various biochemical pathways.

Pharmacokinetics

Tissue pharmacokinetics is not applicable in the same manner as it is for drugs. However, the healing and regeneration of tissues can be influenced by factors such as blood supply, the presence of growth factors, and the metabolic state of the cells within the tissue. In general, the rate of healing and turnover varies significantly among different tissue types, with some, like epithelial tissue, having a faster turnover rate compared to others, like neural tissue.

Pregnancy

Safety during pregnancy is not established. Use only if clearly needed and after evaluating risks versus benefits.

Breast-feeding

Caution is advised, as it is unknown if tissue can affect breastfed infants.

Storage

Store in a cool, dry place, away from direct sunlight and moisture.