FirstHope 
Cosmetics are products used to enhance or alter the appearance, fragrance, or texture of the human body, especially the skin, hair, and nails. Cosmetics include makeup, skincare, and personal care items designed to improve hygiene, beautify, and promote confidence. Lipsticks: Definition: Lipsticks are solid, wax-based products intended to color and protect the lips. The primary … Read more
Phenylephrine is a selective α<sub>1</sub>-adrenergic receptor agonist commonly used as a decongestant, vasopressor, and mydriatic agent. It works by stimulating α<sub>1</sub>-receptors, leading to vasoconstriction, which reduces nasal congestion and increases blood pressure. Chemical Structure & Formula Chemical Formula: C₉H₁₃NO₂ Structure: Mechanism of Action (Detailed) Selective α1 agonist → Causes vasoconstriction. Increases blood pressure without affecting … Read more
Epinephrine, also known as adrenaline, is a hormone and neurotransmitter produced by the adrenal glands. It plays a key role in the body’s “fight-or-flight” response by increasing heart rate, expanding airways, raising blood pressure, and mobilizing energy stores. Chemical Structure & Formula Chemical Formula: C₉H₁₃NO₃ Structure: Mechanism of Action (Detailed) Epinephrine acts on both α … Read more
Norepinephrine (Noradrenaline) is a neurotransmitter and hormone that plays a key role in the body’s “fight-or-flight” response. It is produced primarily in the adrenal medulla and by certain neurons in the central and peripheral nervous systems. Chemical Structure & Formula Chemical Formula: C₈H₁₁NO₃ Structure: Mechanism of Action (Detailed) It is primarily acts on α1, α2, … Read more
Structure-Activity Relationship mimic catecholamines (epinephrine, norepinephrine, dopamine) by stimulating adrenergic receptors (α and β). Their activity depends on structural modifications affecting receptor selectivity, metabolism, and CNS penetration. Key Structure-Activity Relationship Features Catechol Ring Substitutions 3,4-Dihydroxy (Catechol): High α/β activity, rapid metabolism (e.g., Epinephrine, Norepinephrine). Single Hydroxyl (-OH) Group: Reduces metabolism, increases α1 selectivity (e.g., Phenylephrine). No … Read more
Sympathomimetic Agents the actions of endogenous catecholamines. They are broadly classified into three groups based on their mechanism of action: Classification of Sympathomimetic Agents Sympathomimetic agents are drugs that mimic the actions of the sympathetic (adrenergic) nervous system. They are classified based on their mechanism of action in activating adrenergic receptors. 1. Direct-Acting Sympathomimetics Mechanism: These … Read more
Adrenergic receptors are G-protein-coupled receptors (GPCRs) that mediate the effects of norepinephrine and epinephrine. Adrenergic receptors are classified into Alpha (α) and Beta (β) receptors, with further subtypes. Alpha-Adrenergic Receptors (α-Receptors) These receptors mainly mediate vasoconstriction and smooth muscle contraction. α1-Receptors (Gq-coupled) Mechanism: Activate phospholipase C (PLC) → Increase IP3 & DAG → Increase intracellular … Read more
Catecholamines are degraded primarily by Monoamine Oxidase (MAO) and Catechol-O-Methyltransferase (COMT) into inactive metabolites, which are excreted in urine. Steps of Catecholamines Catabolism MAO Pathway: MAO (located in neuronal mitochondria) oxidizes catecholamines into dihydroxyphenylglycol aldehyde. This is further converted into vanillylmandelic acid (VMA) for excretion. COMT Pathway: COMT methylates catecholamines to form metanephrine and normetanephrine. … Read more
Introduction to Hard Gelatin Capsules: Definition: Capsules are solid dosage forms in which the drug substance (active pharmaceutical ingredient, API) and excipients are enclosed in a soluble container or shell. These capsules are cylindrical shells made from gelatin, designed to hold solid or semi-solid drugs. They consist of a cap and body that lock together … Read more
This article explains about the histamine receptor their types functions and how they influence allergic reactions immune responses and other physiological effects. Histamine Receptor: Histamine exerts its effects by binding to four types of histamine receptors, all of which are G protein-coupled receptors (GPCRs): H₁ Receptor H₂ Receptor H₃ Receptor H₄ Receptor Each receptor subtype … Read more
