When topical treatments have been unsuccessful or sweating occurs in areas not suitable for topical treatments or after ETS surgery then medications can sometimes be prescribed. Most are unlicensed for the treatment of hyperhidrosis.
There are a few medications that can be prescribed to reduce sweating and most belong to a group called anticholinergics (sometimes also called antimuscarinics). They work by blocking the chemical at the end of the nerves so it cannot work on the sweat glands. The major problem with such drugs is that they work on all glands and tissues in the body that are controlled by that chemical (called acetylcholine) and as well as reducing sweating they tend to have other effects such as dry mouth, constipation, difficulty urinating which is why many people stop using them.
The two most popular drugs are glycpyrronium bromide (Robinul) and oxybutynin (Lyrinel). Some patients find the latter one in its modified release form more tolerable.
Glycopyrronium bromide is licensed for using with iontophoresis when using tap water alone has not worked. It is quite difficult to get hold of and is very expensive so not used frequently.
Propantheline bromide is licensed for a specific type of sweating called gustatory sweating which includes a condition called Frey’s syndrome.
There is a pharmacy in Canada that makes impregnated wipes for treating hyperhidrosis but these are not licensed in the UK. You can get more details here.