Month: August 2025

Drugs for Myasthenia Gravis include cholinesterase inhibitors, immunosuppressants, and corticosteroids to improve muscle strength. Pharmacological Goal: To increase acetylcholine availability at the neuromuscular junction and/or suppress the autoimmune response. Main Classes of Drugs: Cholinesterase Inhibitors (First-line therapy): Mechanism: Inhibit the enzyme acetylcholinesterase, increasing ACh levels at the neuromuscular junction. Examples: Pyridostigmine (preferred) Neostigmine Adverse Effects: … Read more

Myasthenia Gravis (MG) is an autoimmune disorder causing muscle weakness due to impaired neuromuscular transmission. A chronic autoimmune neuromuscular disorder that causes weakness in the skeletal muscles. Cause of Myasthenia Gravis (MG): Autoantibodies block or destroy acetylcholine receptors at the neuromuscular junction. Symptoms of Myasthenia Gravis (MG): Muscle weakness that worsens with activity (fatigue) Drooping … Read more

Local anesthetic agents block nerve conduction at the site, causing temporary loss of sensation without unconsciousness. Definition of Local Anesthetic Agents: Local anesthetics (LAs) are drugs that block nerve conduction when applied locally to nerve tissues. They reversibly inhibit the perception of pain without causing loss of consciousness. Mechanism of Action: Local anesthetics work by: … Read more

Peripheral skeletal muscle relaxants reduce muscle spasms and tone by blocking neuromuscular activity. These are drugs that act peripherally on skeletal muscle to reduce muscle tone or cause muscle paralysis. They do not have central nervous system (CNS) effects, unlike centrally acting muscle relaxants. Classification of Peripheral Skeletal Muscle Relaxants Non-Depolarizing Neuromuscular Blockers (Competitive antagonists) … Read more

Neuromuscular blocking agents cause muscle relaxation by blocking transmission at neuromuscular junctions. Neuromuscular Blocking Agents (NMBAs) These are drugs that interfere with transmission of nerve impulses at the neuromuscular junction (NMJ). They cause paralysis of skeletal muscles by blocking the action of acetylcholine (ACh), the neurotransmitter that mediates nerve impulses to muscles. They do not … Read more

Sympatholytic drugs block adrenergic activity, lowering blood pressure and reducing heart rate. (Also called Adrenergic Antagonists) Definition of Sympatholytic Drugs: These drugs block the effects of the sympathetic nervous system by inhibiting adrenergic receptors. Classification with Mechanism: Alpha-blockers: Non-selective: Phenoxybenzamine, Phentolamine Selective α1 blockers: Prazosin, Terazosin Beta-blockers: Non-selective: Propranolol Selective β1 blockers: Atenolol, Metoprolol Centrally … Read more

Sympathomimetic drugs stimulate adrenergic receptors, increasing heart rate, blood pressure, and bronchodilation. (Also called Adrenergic Agonists) Definition of Sympathomimetic Drugs: These drugs mimic the effects of the sympathetic nervous system by activating adrenergic receptors (alpha and beta receptors). Classification with MOA: Direct-acting: Act directly on adrenergic receptors (e.g., epinephrine, dobutamine) Indirect-acting: Increase release or prevent … Read more

Parasympatholytic Drugs block acetylcholine action in the parasympathetic system, reducing secretions, relaxing smooth muscles, and increasing heart rate (Also called Anticholinergics or Cholinergic Antagonists) Definition of Parasympatholytic Drugs: These drugs block the effects of the parasympathetic nervous system by inhibiting acetylcholine at muscarinic receptors. Examples of Parasympatholytic Drugs: Atropine – prototype drug Scopolamine – used … Read more