theodrenaline

Action and Spectrum

Actions and Spectrum: 

theodrenaline is a medication with a broad spectrum of actions primarily centered around its effects on the sympathetic nervous system. It acts on both alpha-adrenergic and beta-adrenergic receptors in the body. Its alpha-adrenergic actions include vasoconstriction of blood vessels, leading to enhanced peripheral resistance and blood pressure elevation. This makes theodrenaline a valuable medication in treating hypotension and shock, where it helps restore adequate blood pressure and tissue perfusion.

Furthermore, the stimulation of alpha-1 receptors causes pupil dilation and inhibits gut motility, affecting various physiological functions. Additionally, its activation of beta-1 receptors in the heart increases heart rate and contractility, enhancing cardiac output. These combined effects make theodrenaline effective in addressing conditions like bradycardia and cardiogenic shock. 

While theodrenaline also has some bronchodilatory effects through stimulating beta-2 receptors in the airways, it is less selective than other medications designed explicitly for bronchoconstriction relief. Thus, its use in treating respiratory conditions like asthma is limited. Overall, theodrenaline’s actions are diverse, making it a valuable tool in various clinical scenarios where its ability to raise blood pressure, improve cardiac output, and influence other physiological processes can be harnessed to support patients in critical conditions.

Drug Interaction

Adverse Reaction

Frequency not defined 

Palpitations 

Black Box Warning

Black Box Warning: 

None 

Contraindication / Caution

Contraindication/Caution: 

Contraindication 

• Hypersensitivity: Individuals with a known hypersensitivity or allergy to theodrenaline or related medications should not use it. 
• Hypertension: theodrenaline can significantly increase blood pressure. It should generally be avoided in individuals with severe hypertension or uncontrolled high blood pressure. 
• Heart Conditions: theodrenaline can increase heart rate and contractility. It should be used cautiously in individuals with heart conditions like angina, arrhythmias, or a recent heart attack. 
• Hypovolemia: It should be avoided in severe hypovolemia (low blood volume) as it can worsen tissue perfusion. 
• Pheochromocytoma: This is an infrequent adrenal gland tumor that can release excessive amounts of catecholamines, including noradrenaline. theodrenaline is contraindicated in individuals with pheochromocytoma, as it can exacerbate the condition. 
• Closed-Angle Glaucoma: theodrenaline’s pupillary dilation effects can be problematic in individuals with closed-angle glaucoma, where increased intraocular pressure can damage vision. 
• Thyroid Disease: Individuals with hyperthyroidism (overactive thyroid) may be more sensitive to the effects of theodrenaline. 
• Diabetes: theodrenaline can raise blood sugar levels by promoting the release of glucose from liver and inhibiting insulin release. It should be used cautiously in individuals with diabetes, and blood glucose levels should be closely monitored. 
• Severe Peripheral Arterial Disease: In cases of severe peripheral arterial disease, where blood flow to the extremities is already compromised, theodrenaline can worsen blood flow and potentially damage tissue. 
• Labor and Delivery: theodrenaline should be used cautiously during labor and delivery, as it can affect uterine blood flow and contractions. 
• MAO Inhibitors: Monoamine oxidase (MAO) inhibitors, a type of medication used to treat depression and other conditions, can enhance the effects of theodrenaline and may lead to dangerously high blood pressure. 

Caution 

• Hypertension: theodrenaline can significantly increase blood pressure. Caution should be exercised when administering it to individuals with preexisting hypertension, as it can exacerbate high blood pressure and lead to complications. 
• Arrhythmias: theodrenaline’s stimulation of beta-1 receptors in the heart can lead to arrhythmias, especially in individuals with preexisting heart rhythm disorders. It should be used cautiously in such cases. 
• Ischemic Heart Disease: Individuals with the ischemic heart disease or a history of myocardial infarction should be monitored closely when receiving theodrenaline, as it can increase myocardial oxygen demand and potentially worsen ischemia. 
• Peripheral Arterial Disease: theodrenaline may worsen peripheral arterial disease, where blood flow to the extremities is already compromised. It can exacerbate tissue ischemia. 
• Phaeochromocytoma: theodrenaline is contraindicated in individuals with phaeochromocytoma, a rare adrenal gland tumor, as it can precipitate severe hypertension and other complications. 
• Closed-Angle Glaucoma: theodrenaline’s pupil dilation effect can be problematic in individuals with closed-angle glaucoma, which can increase intraocular pressure. 
• Diabetes: It can raise blood sugar levels by promoting the release of glucose from liver and inhibiting insulin release. Caution should be exercised when administering it to individuals with diabetes, and blood glucose levels should be monitored. 
• MAO Inhibitors: theodrenaline’s effects can be potentiated by monoamine oxidase (MAO) inhibitors, increasing the risk of hypertensive crisis. Concurrent use should be avoided or managed with extreme caution. 
• Pregnancy and Lactation: The use of theodrenaline during pregnancy and lactation should be carefully considered, as it can affect uterine blood flow and milk production. 
• Geriatric Patients: Elderly individuals may be more sensitive to the cardiovascular effects of theodrenaline and may require lower doses. 
• Pediatric Patients: The use of theodrenaline in children should be closely monitored and tailored to the individual patient’s needs. 
• Drug Interactions: theodrenaline can interact with other medications, such as those affecting blood pressure, heart rate, or MAO inhibitors.

Pregnancy / Lactation

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. 
• <b>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. 

Pharmacology

Pharmacology: 

theodrenaline is a sympathomimetic medication that primarily acts on the sympathetic nervous system. It functions as an alpha-adrenergic agonist, causing vasoconstriction by stimulating alpha receptors in smooth muscle, and a beta-adrenergic agonist, leading to increased heart rate and contractility by activating beta receptors in the heart.

These actions result in an overall elevation of blood pressure and cardiac output, making theodrenaline helpful in treating conditions such as hypotension, shock, bradycardia, and some instances of bronchoconstriction. However, its administration requires careful medical supervision due to its potent effects on the cardiovascular system and other potential side effects, and the choice of dosage and route depends on the specific clinical context and patient requirements. 

Pharmacodynamics: 

Mechanism of action: theodrenaline exerts its physiological effects by binding to and also activating specific receptors in the body. Its mechanism of action involves interactions with adrenergic receptors, specifically alpha-adrenergic and beta-adrenergic receptors.  

Alpha-Adrenergic Receptors: theodrenaline stimulates alpha-adrenergic receptors found primarily in the smooth muscle of blood vessels. When theodrenaline binds to these receptors, it triggers several responses: 

• Vasoconstriction: Activation of alpha-1 adrenergic receptors in arterial smooth muscle leads to vasoconstriction, which narrows the blood vessels. This results in an increase in peripheral resistance and blood pressure. 
• Pupil Dilation: Stimulation of alpha-1 receptors in the radial muscle of the iris causes pupil dilation (mydriasis). 
• Inhibition of Gut Motility: Alpha-2 adrenergic receptor activation in the gastrointestinal tract can lead to decreased gut motility. 

Beta-Adrenergic Receptors: theodrenaline also stimulates beta-adrenergic receptors, primarily the beta-1 and beta-2 receptor subtypes. These receptors are found in the heart and smooth muscle of the airways, respectively: 

Heart Effects (Beta-1): Activation of beta-1 receptors in the heart leads to an increase in heart rate (positive chronotropic effect) and an increase in the force of contraction (positive inotropic effect). This results in an increased cardiac output. 

Bronchodilation (Beta-2): Activation of beta-2 receptors in the smooth muscle of the bronchioles causes relaxation, leading to bronchodilation. This can help relieve bronchoconstriction and improve airflow, although theodrenaline is less selective for beta-2 receptors than other bronchodilators. 

Pharmacokinetics: 

Absorption 

theodrenaline is typically administered through intravenous (IV) infusion, allowing rapid and reliable absorption directly into the bloodstream. When given intravenously, the drug’s effects are immediate and predictable. 

Distribution 

theodrenaline is a naturally occurring catecholamine widely distributed throughout the body upon absorption. It acts on both alpha-adrenergic and beta-adrenergic receptors. Its distribution includes effects on the heart, blood vessels, and other tissues where adrenergic receptors are found. 

Metabolism 

theodrenaline is primarily metabolized in the liver by the enzyme monoamine oxidase (MAO). MAO breaks down theodrenaline into inactive metabolites, including dihydroxymandelic acid (DOMA) and dihydroxyphenylglycol (DHPG). These metabolites are eventually conjugated and excreted in the urine. 

Elimination and Excretion 

The metabolites of theodrenaline, particularly DOMA and DHPG, are excreted in the urine. Some unmetabolized theodrenaline may also be excreted in the urine. The elimination half-life of theodrenaline is relatively short, typically on the order of a few minutes, which means it is rapidly removed from the body. 

Adminstartion

Administration: 

The administration of theodrenaline should always be carried out by a trained healthcare professional, typically in a hospital/clinical setting, due to its potent effects on blood pressure and the cardiovascular system. The specific route and dosage of theodrenaline can vary based on the patient’s condition and the clinical context.  

Intravenous (IV) Infusion: Intravenous administration is the most common route for theodrenaline. It is typically administered as a continuous infusion through an IV line. This allows for precise control of the dosage and immediate response to changes in blood pressure. 

• The healthcare provider will determine the concentration and rate of theodrenaline infusion based on the patient’s blood pressure and response to the medication. 

Intraosseous (IO) Route: In emergencies where IV access is difficult, theodrenaline may be administered intraosseous. This generally involves inserting a needle into the bone marrow cavity to deliver the medication directly into the bloodstream. 

Arterial Line: Sometimes, theodrenaline may be administered directly into an artery using an arterial line. This allows for precise control of blood pressure in critical care settings. 

Endotracheal Tube: In rare cases, theodrenaline can be administered through an endotracheal tube when other routes are not feasible. However, this is not the preferred route of administration. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: theodrenaline 

Why do we use theodrenaline? 

theodrenaline is a medication with various medical uses because of its effects on the sympathetic nervous system.  

• Hypotension (Low Blood Pressure): theodrenaline is often used to treat acute episodes of severe hypotension, especially when other failed treatments.  
• Shock: In cases of shock, with a critical drop in blood pressure and reduced tissue perfusion, theodrenaline can be administered to help stabilize blood pressure and improve organ perfusion. 
• Cardiogenic Shock: theodrenaline may be used in cases of cardiogenic shock, a condition where the heart cannot pump enough blood to meet body’s needs. It can increase heart rate and cardiac contractility to improve cardiac output. 
• Bradycardia: theodrenaline can increase heart rate when patients have dangerously slow heart rates (bradycardia), especially if it is causing symptoms like dizziness or syncope. 
• Asthma and Bronchoconstriction: Although less commonly used for this purpose compared to other medications like albuterol, theodrenaline’s bronchodilatory effects can help relax the smooth muscles in the airways and provide relief in some cases of acute bronchoconstriction, such as in severe asthma attacks. 
• Perioperative Hypotension: theodrenaline may be used during surgical procedures to counteract hypotension due to anesthesia or other factors. 
• Septic Shock: In septic shock, where an infection leads to widespread inflammation and low blood pressure, theodrenaline can be used as a treatment strategy to maintain blood pressure and perfusion. 
• Postoperative Hypotension: Patients may experience low blood pressure after surgery, and theodrenaline can address this issue. 
• Spinal Anesthesia-Induced Hypotension: When spinal anesthesia causes a drop in blood pressure during specific surgical procedures, theodrenaline may be administered to counteract this effect.