Neostigmine is a competitive irreversible inhibitor of Acetylcholinesterase (AChE), an enzyme responsible for breaking down acetylcholine (ACh). Myasthenia gravis is caused by the body producing too little ACh receptors. As stimulating the ACh receptors is needed for nervous transmission, the nerve signals cannot be transmitted causing muscle weakness and fatigue. Neostigmine is hence used to inhibit AChE so that less ACh gets broken down. This leads to more ACh binding to the ACh receptors causing muscular contraction.
Are used medicinally:To treat myasthenia gravis. In myasthenia gravis, they are used to increase neuromuscular transmission.To treat GlaucomaTo treat Alzheimer's diseaseTo treat Lewy Body DementiaAs an antidote to anticholinergic poisoning
they stimulate the action of ACh at post ganglionic muscarinic receptors.
Corticosteroids provide significant improvement or complete relief of symptoms in more than 75% of people, and some improvement occurs in most of the rest.
The severity ranges depending on how long the patient has been living with the condition. Certain medications may be used to treat symptoms and slow down the disease progression.
these drugs improve the nerve signals to the muscles therefore there will be an increase in the muscle strength.
Thymectomy or thymus removal is recommended for most with this disease. Greatest benefit occurs 2 to 5 years afterwards. The best response are in young people early in the onset.
Plasma exchange is used as a short-term intervention for patients with sudden worsening of symptoms, to rapidly improve strength before surgery, and as a chronic intermittent treatment.
Physical and occupational therapists provide strategies to maintian daily activities. Shower stools, rolling carts for shopping and exercises to maintain posture all help avoid fatigue.
Immune globulin given intravenously results in improvement in more than half of MG patients, usually beginning within one week of therapy and lasting for several weeks or months.
Possible side effects include drug contraindications that interfere with cyclosporine metabolism and life threatening infections are a risk.
Acetylcholinesterase inhibitors: Reversible:1.Physostigmine -Miotic, cycloplegic and reduces IOT 0.25-0.5 % drops -Atropine, and antidepressant poisoning with predominant CNS manifestations (crosses BBB) 2.Neostigmine-Doesnt cross BBB, hence good for d.tubocurare muscle blockade -Myasthenia -Post op ileus -Decurarisation 3.Pyridostigmine-Similar but less potent and long acting than neostigmine. Better tolerated in myasthenic patients 4.Edrophonium -Dx of myasthenia -Cobra bites 5.Rivastigmine -Alzhiemers(?) Irreversible: -Mostly pesticides DFP,Malathoin,Parathoin,Sarin, Soman (Nerve gas) -Metrifonate(Antihelminthic drug)
Botulism affects many body parts because it can cause blurred vision, weak muscles, stomach cramping, nausea, and difficulty of breathing.