Perineural catheters that provide local anesthetic agents have poor evidence of success when placed after surgery in an effort to prevent phantom limb pain.One approach that has received public interest is the use of a mirror box. The mirror box provides a reflection of the intact hand or limb that allows the patient to "move" the phantom limb, and to unclench it from potentially painful positions.Although mirror therapy was introduced by VS Ramachandran in the early 1990s, little research was done on it before 2009, and much of the subsequent research has been of poor quality, according to a 2016 review. A 2018 review, which also criticized the scientific quality of many reports on mirror therapy (MT), found 15 good-quality studies conducted between 2012 and 2017 (out of a pool of 115 publications), and concluded that "MT seems to be effective in relieving PLP, reducing the intensity and duration of daily pain episodes. It is a valid, simple, and inexpensive treatment for PLP." Other phantom sensations
Phantom sensations may also occur after the removal of body parts other than the limbs, e.g. after amputation of the breast, extraction of a tooth (phantom tooth pain) or removal of an eye (phantom eye syndrome).Some people who have undergone gender reassignment surgery have reported the sensation of phantom genitals. The reports were less common among post-operative transgender women, but did occur in transgender men. Similarly, subjects who had undergone mastectomy reported experiencing phantom breasts; these reports were substantially less common among post-operative transgender men.
Foscarnet (phosphonomethanoic acid), known by its brand name Foscavir, is an antiviral medication which is primarily used to treat viral infections involving the Herpesviridae family. It is classified as a pyrophosphate analog DNA polymerase inhibitor. Foscarnet is the conjugate base of a chemical compound with the formula HO2CPO3H2 (Trisodium phosphonoformate).Foscarnet was approved for medical use in 1991. Medical use
This phosphonic acid derivative (marketed by Clinigen as foscarnet sodium under the trade name Foscavir) is an antiviral medication used to treat herpes viruses, including drug-resistant cytomegalovirus (CMV) and herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2). It is particularly used to treat CMV retinitis. Foscarnet can be used to treat highly treatment-experienced patients with HIV as part of salvage therapy. Mechanism of action
Foscarnet is a structural mimic of the anion pyrophosphate that selectively inhibits the pyrophosphate binding site on viral DNA polymerases at concentrations that do not affect human DNA polymerases.In individuals treated with the DNA polymerase inhibitors acyclovir or ganciclovir, HSV or CMV particles can develop mutant protein kinases (thymidine kinase or UL97 protein kinase, respectively) that make them resistant to these antiviral drugs. However, unlike acyclovir and ganciclovir, foscarnet is not activated by viral protein kinases, making it useful in acyclovir- or ganciclovir-resistant HSV and CMV infections.However, acyclovir- or ganciclovir-resistant mutants with alterations in viral DNA polymerase may also be resistant to foscarnet. Administration
Foscarnet is administered by intravenous infusion or intravitreous injection. Side effects
Nephrotoxicity — increase in serum creatinine levels and renal injury can occur in patients receiving foscarnet.