A non-depolarising block

Studies were carried out on the possible neuromuscular blocking actions of chloroquine diorotate in animals, because it was noticed that when it was used in the peritoneal cavity to prevent adhesions following abdominal surgery in man, it caused respiratory insufficiency during the recovery period. These studies found that it had a non-depolarising blocking action at the neuromuscular junction, which was opposed by neostigmine. It... 

The block may change into a non-depolarising type (phase II block) after high doses (7-10 mg-kg-1) of the drug have been administered. A phase II block shows the characteristics of a nondepolarising block with slow recovery. 

Clinically, IMS resembles the syndrome of incomplete reversal of neuromuscular paralysis by non-depolarising blocking agents sometimes seen following general anaesthesia. Patients will recover after a week or 10 days if intensive care facilities are available with intermediate positive pressure variation. Unfortunately, OP pesticide poisoning often occurs in countries that have the least available resources in terms of intensive care. 

The interaction between quinidine and neuromuscular blockers is an established interaction of clinical importance, but the documentation is limited. The incidence is uncertain, but it was seen in one report cited to a greater or lesser extent in 5 of the 6 patients studied.- It has only been reported clinically with metocurine, tubocurarine and suxamethonium, but it occurs in animals with gallamine, and it seems possible that it could occur clinically with any depolarising or non-depolarising neuromuscular blocker. Be alert for increased neuromuscular blocking effects during and after surgery. 

The peroxynitrite generator SIN-1 (0.5 mM) induced apoptosis both in src oncogene-transformed and non-transformed rat fibroblasts 208 F, indicating that peroxynitrite is no selective apoptosis inducer per se, but that selective apoptosis induction in transformed cells by NO is achieved through selective peroxynitrite generation (Heigold et al. 2002). The interaction of NO with target cell derived superoxide anions represents a novel concept for selective apoptosis induction in transformed cells. Apoptosis induction mediated by NO involves mitochondrial depolarisation and is blocked by Bcl-2 overexpression. 

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