guanadrel sulfate

Action and Spectrum

Actions and Spectrum: 

Action:  

guanadrel sulfate works by inhibiting the release of norepinephrine (noradrenaline) from nerve endings in the sympathetic nervous system. Norepinephrine serves as a neurotransmitter predominantly responsible for initiating the narrowing of blood vessels, resulting in heightened blood pressure. Through the inhibition of norepinephrine discharge, guanadrel sulfate facilitates the relaxation and expansion of blood vessels, thereby decreasing blood pressure. 

Spectrum: 

guanadrel sulfate primarily targets the sympathetic nervous system and its effects are mainly related to the cardiovascular system. It is specifically used to treat hypertension (high blood pressure) and was often prescribed when other antihypertensive agents were ineffective or caused intolerable side effects. 

Drug Interaction

Adverse Reaction

Frequency not defined  

Fatigue 

Sleep disorders 

Bradycardia 

Drowsiness 

Headache 

Dry mouth 

constipation 

Black Box Warning

Black Box Warning:  

guanadrel sulfate is associated with serious cardiovascular effects, including marked hypotension, bradycardia, and a potential risk of syncope (fainting). This drug acts by reducing sympathetic nervous system activity and can result in significant drops in blood pressure. 

Contraindication / Caution

Contraindication/Caution:  

Hypersensitivity: Individuals with a known hypersensitivity or allergy to guanadrel sulfate or its components should not take this medication. 

Severe Coronary Insufficiency: guanadrel sulfate may exacerbate severe coronary insufficiency,characterized by inadequate blood supply to the heart muscle. It can lead to worsening of symptoms or potential complications. 

Heart Block: This medication can worsen heart block, a condition where the electrical signals in the heart are disrupted, leading to slow heart rates and potential cardiac complications. 

History of Mental Depression: guanadrel sulfate can have central nervous system effects and may exacerbate symptoms of mental depression or other psychiatric disorders. 

Peptic Ulcer: The use of guanadrel sulfate can lead to increased gastric acid secretion, which may exacerbate peptic ulcers. 

Asthma or Chronic Obstructive Pulmonary Disease (COPD): guanadrel sulfate can cause bronchoconstriction and worsen respiratory symptoms in individuals with asthma or COPD. 

Kidney Disease: Since guanadrel sulfate is excreted primarily by the kidneys, individuals with severe kidney impairment should be cautious when using this medication. 

Pregnancy and Breastfeeding: The safety of guanadrel sulfate during pregnancy and breastfeeding has not been well established. It is generally recommended to avoid its use during these periods. 

Pregnancy / Lactation

Pregnancy warnings:     

Pregnancy category: B 

Lactation: Excreted into human milk is unknown 

Pregnancy Categories:         

Category A: Studies that were well-controlled and met expectations revealed no risk to the fetus in either the first or second trimester. 

Category B: There were a lack of studies on pregnant women and no evidence of risk to the fetus in animal experiments.   

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:  

guanadrel sulfate is a medication that was primarily used to treat hypertension (high blood pressure). 

Pharmacodynamics:  

guanadrel sulfate is a sympatholytic drug that acts as a false neurotransmitter. It is taken up into the sympathetic nerve terminals by the same transport mechanisms that normally take up norepinephrine. Once inside the nerve terminal, guanadrel is stored in vesicles alongside norepinephrine. When nerve stimulation triggers the release of vesicular contents into the synaptic cleft, both norepinephrine and guanadrel are released.    

Pharmacokinetics: 

Absorption 

guanadrel sulfate is orally administered, and its absorption from the gastrointestinal tract is relatively slow and incomplete. The ingestion of food in the stomach can also delay absorption. 

Distribution 

guanadrel sulfate is distributed throughout the body. It is highly bound to plasma proteins. It crosses the blood-brain barrier, allowing it to exert its effects in the central nervous system. 

Metabolism 

guanadrel sulfate undergoes minimal metabolism in the body. The drug’s metabolism is not a significant factor in its elimination. 

Excretion and Elimination 

The primary route of elimination for guanadrel sulfate is renal (through the kidneys). It is excreted primarily in the urine, with a small portion being eliminated in the feces. The drug’s elimination half-life is in the range of several hours. 

Adminstartion

Administration:  

guanadrel sulfate is typically available in tablet form. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: guanadrel sulfate 

Why do we use guanadrel sulfate?  

Hypertension Management:  

guanadrel sulfate is prominently prescribed for managing essential hypertension, accounting for a significant portion of hypertension cases. As an adjunct to comprehensive therapeutic regimens, guanadrel sulfate aids in achieving blood pressure control and mitigating the associated risks of cardiovascular complications, target organ damage, and related morbidity and mortality.