Peripheral Nervous System (PNS) is the part of the nervous system outside the brain and spinal cord, consisting of cranial nerves, spinal nerves, and peripheral ganglia. It connects the central nervous system (CNS) to limbs and organs, enabling sensory input and motor responses. The PNS includes all nerves outside the brain and spinal cord. It … Read more
Definition of Sedatives and Hypnotics Sedatives and hypnotics are central nervous system (CNS) depressants that reduce anxiety (anxiolytic effect), induce sedation (calming effect), or promote sleep (hypnotic effect). The same compound may act as a sedative or hypnotic depending on the dose and pharmacokinetics. Classification 1. Benzodiazepines Mechanism (brief) Enhance the effect of GABA (gamma-aminobutyric … Read more
Ethopropazine Hydrochloride manages Parkinson’s disease symptoms by reducing tremors and rigidity. Ethopropazine Hydrochloride is an anticholinergic agent with central nervous system activity. Chemical Formula: C₁₉H₂₄N₂S·HCl Mechanism of Action: Anticholinergic + mild antihistaminic Used as a CNS agent for movement disorders Therapeutic Uses of Ethopropazine Hydrochloride: Parkinsonism Drug-induced tremors or rigidity Side Effects of Ethopropazine Hydrochloride: … Read more
Isopropamide Iodide treats peptic ulcers, reducing gastric acid and motility. Isopropamide Iodide is a long-acting anticholinergic agent. Chemical Formula: C₂₁H₂₈INO Mechanism of Action: Long-acting M1/M3 blocker → mainly GI tract Poor CNS penetration due to quaternary nitrogen Therapeutic Uses: GI disorders (ulcers, IBS) Functional abdominal pain Side Effects: Dry mouth Constipation Urinary retention Tachycardia
Tridihexethyl Chloride treats peptic ulcers by reducing gastric acid secretion. Tridihexethyl Chloride is an anticholinergic blocking muscarinic receptors. Chemical Formula: C₂₂H₄₈ClNO Mechanism of Action of Tridihexethyl Chloride: Non-selective muscarinic blocker Peripheral action → no CNS effect Therapeutic Uses of Tridihexethyl Chloride: Peptic ulcer GI spasm Bladder instability Side Effects: Dry mouth Constipation Tachycardia Blurred vision
Procyclidine Hydrochloride treats Parkinson’s disease symptoms and drug-induced extrapyramidal disorders. Procyclidine Hydrochloride is an anticholinergic that reduces muscle stiffness, tremors, and improves mobility. Chemical Formula: C₁₉H₂₉NO·HCl Mechanism of Action: Centrally acting M1 antagonist Some direct spasmolytic activity Therapeutic Uses: Parkinson’s disease Antipsychotic-induced EPS Side Effects: Drowsiness Confusion Dry mouth Constipation Visual disturbances SAR (Structure–Activity Relationship) … Read more
Transmembrane Enzyme-Linked Receptors are cell-surface receptors that activate intracellular enzymes upon ligand binding, regulating growth, metabolism, and cell signaling. These receptors have intrinsic enzymatic activity (often kinase activity). Most Common Type: Receptor Tyrosine Kinases (RTKs) Structure of Transmembrane Enzyme-Linked Receptors: Single transmembrane domain Extracellular ligand-binding site Intracellular tyrosine kinase domain Mechanism: Ligand binds to the … Read more
Transmembrane JAK-STAT Binding Receptors are receptors that activate JAK kinases on ligand binding, triggering STAT pathways to regulate gene expression. These receptors lack intrinsic kinase activity but associate with cytoplasmic enzymes, specifically Janus Kinases (JAKs). Structure of Transmembrane JAK-STAT Binding Receptors: Single transmembrane receptor No intrinsic enzymatic domain Mechanism: Ligand (e.g., cytokine) binds to receptor … Read more
Intracellular Receptors Regulating Transcription Factors are receptors inside cells that bind ligands and directly influence gene expression. These receptors are located inside the cell, either in the cytoplasm or nucleus. They bind lipid-soluble ligands that cross the plasma membrane. Structure of Intracellular Receptors Regulating Transcription Factors: Ligand-binding domain DNA-binding domain (zinc finger motifs) Transcriptional regulatory … Read more
Dose-Response Relationship describes how the magnitude of a drug’s effect changes with different doses, showing potency and efficacy. The dose-response relationship explains how a drug’s effect changes with varying doses—central to pharmacodynamics. Graded Dose-Response Measures the intensity of response in an individual as dose increases. Displayed as a sigmoidal (S-shaped) curve on a semi-log graph. … Read more
