Research
Brincidofovir is under investigation for the treatment of cytomegalovirus, adenovirus, poxvirus, and ebolavirus infections. It has been used off-label for the treatment of monkeypox. Adenovirus and cytomegalovirus
As of 2014, brincidofovir is in Phase III clinical trials for use in humans against cytomegalovirus and adenovirus. Preliminary safety data from a database of 1000 patients supported progression into later phase trials, Chimerix announced in December 2015 that the Phase III trials for use of the drug in preventing cytomegalovirus infection in stem cell transplant patients had failed, and in February 2016 shut down two other late-stage trials for use of the drug in preventing infection after kidney transplants. Brincidofovir is not yet FDA approved for adenovirus or cytomegalovirus due to lack of efficacy in clinical trials. In a trial of brincidofovir for patients with CMV brincidofovir was associated with a 15.5% week 24 all-cause mortality compared with 10.1% among placebo recipients. Additionally brincidofovir was associated with increased serious adverse events (57.1% versus 37.6%) compared with placebo. Brincidofovir was initially offered via an FDA expanded access trial; however as of May 9, 2019, Chimerix discontinued clinical trials of brincidofovir for the treatment of adenovirus and discontinued the expanded access program in 2019. Ebola
After initial studies by the Centers for Disease Control and Prevention (CDC, Atlanta, GA, USA) in cell culture models, on October 6, 2014, Chimerix received an FDA authorization for emergency investigational new drug applications of brincidofovir for the treatment of Ebola virus disease.
Cycloplegia is paralysis of the ciliary muscle of the eye, resulting in a loss of accommodation. Because of the paralysis of the ciliary muscle, the curvature of the lens can no longer be adjusted to focus on nearby objects. This results in similar problems as those caused by presbyopia, in which the lens has lost elasticity and can also no longer focus on close-by objects. Cycloplegia with accompanying mydriasis (dilation of pupil) is usually due to topical application of muscarinic antagonists such as atropine and cyclopentolate. Belladonna alkaloids are used for testing the error of refraction and examination of eye. Management
Cycloplegic drugs are generally muscarinic receptor blockers. These include atropine, cyclopentolate, homatropine, scopolamine and tropicamide. They are indicated for use in cycloplegic refraction (to paralyze the ciliary muscle in order to determine the true refractive error of the eye) and the treatment of uveitis. All cycloplegics are also mydriatic (pupil dilating) agents and are used as such during eye examination to better visualize the retina. When cycloplegic drugs are used as a mydriatic to dilate the pupil, the pupil in the normal eye regains its function when the drugs are metabolized or carried away. Some cycloplegic drugs can cause dilation of the pupil for several days. The ones specifically used by ophthalmologists or optometrists wear off in hours, but when the patient leaves the office strong sunglasses are provided for comfort. See also
References
External links
Kels, Barry D.; Grzybowski, Andrzej; Grant-Kels, Jane M. (March 2015). "Human ocular anatomy". Clinics in Dermatology. 33 (2): 140–146. doi:10.1016/j.clindermatol.2014.10.006.