Medicinal Chemistry I is a core subject that explores the design, synthesis, and biological activity of drugs. It bridges organic chemistry and pharmacology to enhance understanding of therapeutic agents.
Mephenytoin stabilizes neuronal membranes by reducing repetitive firing through sodium channel blockade. It is an anticonvulsant used in managing generalized tonic-clonic and partial seizures. Chemical Formula: C₁₂H₁₄N₂O₂ Mechanism of Mephenytoin: Sodium channel blocker (like phenytoin) Rapid oral absorption Uses of Mephenytoin: Tonic-clonic and partial seizures (historical) Side Effects: Aplastic anemia (rare but serious) Drowsiness, ataxia … Read more
Phenytoin controls generalized tonic-clonic and partial seizures effectively. It stabilizes neuronal membranes by blocking voltage-gated sodium channels. Chemical Formula: C₁₅H₁₂N₂O₂ Mechanism of Action: Blocks Na⁺ channels in a use-dependent manner → stabilizes hyperexcited neurons. Prevents repetitive firing. Therapeutic Uses: Tonic-clonic seizures Focal (partial) seizures Status epilepticus (IV loading) Side Effects: Gingival hyperplasia Hirsutism Ataxia, diplopia … Read more
Metharbital, a barbiturate, enhances GABA activity, producing anticonvulsant and sedative effects. It is prescribed for epilepsy, offering control over generalized and partial seizures. Chemical Formula: C₉H₁₄N₂O₃ Mechanism of Action: Similar to phenobarbital; enhances GABAergic inhibition Therapeutic Uses of Metharbital: Formerly used for generalized tonic-clonic seizures Less potent, more sedating than phenobarbital Side Effects of Metharbital: … Read more
Phenobarbitone (Phenobarbital) controls epilepsy, seizures, and provides sedative-hypnotic action. It enhances GABA activity, prolonging chloride influx for CNS depression. Chemical Formula: C₁₂H₁₂N₂O₃ Mechanism of Action: Enhances GABA-A activity, prolongs Cl⁻ channel opening. Also reduces glutamate-mediated excitation. Therapeutic Uses of Phenobarbitone (Phenobarbital): Tonic-clonic seizures Partial seizures Status epilepticus (alternative) Febrile seizures (children) Side Effects of Phenobarbitone … Read more
Definition of Anticonvulsants Anticonvulsants (also called antiepileptic drugs or AEDs) are agents used to prevent or reduce the frequency and severity of seizures in epilepsy and other seizure disorders. They work by modulating the activity of excitatory and inhibitory neurotransmitters or ion channels in the brain. Mechanism of Action of Anticonvulsants Anticonvulsants work mainly by: … Read more
Sulpiride is a selective dopamine D2 antagonist with antipsychotic and antidepressant effects. It treats schizophrenia, depression, and anxiety by balancing dopamine activity. Chemical Formula: C₁₅H₂₃N₃O₄S Mechanism of Sulpiride: Selective D2 and D3 antagonist Low affinity for D1, 5-HT, or muscarinic receptors Uses of Sulpiride: Schizophrenia (Europe, Asia) Dysthymia, depression (low doses) Side Effects: Hyperprolactinemia Mild … Read more
Molindone Hydrochloride treats schizophrenia by reducing hallucinations and delusions. It is a typical antipsychotic that blocks dopamine receptors in the brain. Chemical Formula: C₁₆H₂₄N₂O·HCl Mechanism of Molindone Hydrochloride: D2 receptor antagonist (typical antipsychotic) Minimal activity at muscarinic or histaminergic receptors Uses of Molindone Hydrochloride: Schizophrenia Less weight gain than other antipsychotics Side Effects: EPS (moderate … Read more
Risperidone blocks dopamine D2 and serotonin 5-HT2 receptors, stabilizing mood and behavior. It treats schizophrenia, bipolar disorder, and irritability in autism spectrum disorder. Chemical Formula: C₂₃H₂₇FN₄O₂ Mechanism of Risperidone: Antagonist at D2 and 5-HT2A Also affects α1, H1 receptors Uses of Risperidone: Schizophrenia Bipolar disorder Irritability in autism Side Effects: Moderate EPS (esp. at high … Read more
Droperidol is a dopamine antagonist with sedative, antiemetic, and antipsychotic effects. It controls nausea, vomiting, and agitation in surgical and psychiatric settings. Chemical Formula: C₂₂H₂₂FN₃O₂ Mechanism of Droperidol: Potent D2 blocker Also blocks alpha-adrenergic and 5-HT3 receptors Uses of Droperidol: Nausea/vomiting (post-op) Sedation in ICU Agitation (adjunct) Side Effects: QT prolongation (boxed warning) EPS Sedation … Read more
Haloperidol is a typical antipsychotic that blocks dopamine D2 receptors to control symptoms. It treats schizophrenia, acute psychosis, and Tourette’s syndrome effectively. Chemical Formula: C₂₁H₂₃ClFNO₂ Mechanism of Haloperidol: Potent D2 receptor antagonist in mesolimbic system Minimal activity on other receptors (very “clean”) Uses of Haloperidol: Schizophrenia Acute psychosis Delirium Tourette syndrome Severe agitation Side Effects: … Read more
