Pralidoxime has an important role in reversing paralysis of the respiratory muscles but due to its poor blood–brain barrier penetration, it has little effect on centrally-mediated respiratory depression. Atropine, which is choice of drug to antagonise the muscarinic effects of organophosphates, is administered even before pralidoxime during the treatment of organophosphate poisoning. While the efficacy of atropine has been well-established, clinical experience with pralidoxime has led to widespread doubt about its efficacy in treatment of organophosphorus poisoning. Dosage
Adults: 30 mg/kg (typically 1–2 g), administered by intravenous therapy over 15–30 minutes, repeated 60 minutes later. It can also be given as a 500 mg/h continuous IV infusion. Children: 20–50 mg/kg followed by a maintenance infusion at 5–10 mg/kg/h.Intravenous infusions can lead to respiratory or cardiac arrest if given too quickly. Interactions
When atropine and pralidoxime are used together, the signs of atropinization (flushing, mydriasis, tachycardia, dryness of the mouth and nose) may occur earlier than might be expected when atropine is used alone. This is especially true if the total dose of atropine has been large and the administration of pralidoxime has been delayed. The following precautions should be kept in mind in the treatment of anticholinesterase poisoning, although they do not bear directly on the use of pralidoxime: since barbiturates are potentiated by the anticholinesterases, they should be used cautiously in the treatment of convulsions; morphine, theophylline, aminophylline, succinylcholine, reserpine, and phenothiazine-type tranquilizers should be avoided in patients with organophosphate poisoning. Contraindications
There are no known absolute contraindications for the use of pralidoxime.
Research
A study released in April 2009, found that bevacizumab is not effective at preventing recurrences of non-metastatic colon cancer following surgery.Bevacizumab has been tested in ovarian cancer where it has shown improvement in progression-free survival but not in overall survival. and glioblastoma multiforme where it failed to improve overall survival.Bevacizumab has been investigated as a possible treatment of pancreatic cancer, as an addition to chemotherapy, but studies have shown no improvement in survival. It may also cause higher rates of high blood pressure, bleeding in the stomach and intestine, and intestinal perforations.The drug has also undergone trials as an addition to established chemotherapy protocols and surgery in the treatment of pediatric osteosarcoma, and other sarcomas, such as leiomyosarcoma.Bevacizumab has been studied as a treatment for cancers that grow from the nerve connecting the ear and the brain. References
Further reading
Berenson A (15 February 2006). "A Cancer Drug Shows Promise, at a Price That Many Cant Pay". The New York Times. Sachdev JC, Jahanzeb M (October 2008). "Evolution of bevacizumab-based therapy in the management of breast cancer". Clinical Breast Cancer. 8 (5): 402–10. doi:10.3816/CBC.2008.n.048. PMID 18952553. External links
"Bevacizumab". Drug Information Portal. U.S. National Library of Medicine. "Bevacizumab". National Cancer Institute. 5 October 2006. "Bevacizumab". NCI Drug Dictionary.