Glycopyrronium bromide
Glycopyrronium bromide is a medication of the muscarinic anticholinergic group. It does not cross the blood–brain barrier and consequently has few to no central effects. It is available in oral, intravenous, topical, and inhaled forms. It is a synthetic quaternary ammonium compound.The cation, which is the active moiety, is called glycopyrronium (INN) or glycopyrrolate (USAN).
In June 2018, glycopyrronium was approved by the US Food and Drug Administration (FDA) to treat excessive underarm sweating, becoming the first drug developed specifically to reduce excessive sweating. It is on the World Health Organizations List of Essential Medicines.

Medical uses
Glycopyrronium was first used in 1961 to treat peptic ulcers. Since 1975, intravenous glycopyrronium has been used before surgery to reduce salivary, tracheobronchial, and pharyngeal secretions. It is also used in conjunction with neostigmine, a neuromuscular blocking reversal agent, to prevent neostigmines muscarinic effects such as bradycardia. It can be administered to raise the heart rate in bradycardia, which often will also increase the blood pressure.
It is also used to reduce excessive saliva (sialorrhea), and Ménières disease.It has been used topically and orally to treat hyperhidrosis, in particular, gustatory hyperhidrosis.In inhalable form it is used to treat chronic obstructive pulmonary disease (COPD). Doses for inhalation are much lower than oral ones, so that swallowing a dose will not have an effect.In end-of-life care, this medication will often be administered to patients that become encumbered by their bronchial secretions and are no longer able to clear their own airway through insufficient coughing reflex.

Side effects
Dry mouth, urinary retention, headaches, vomiting, diarrhea, constipation, blurry vision are possible side effects of the medication. Since glycopyrronium reduces the bodys sweating ability, it can even cause hyperthermia and heat stroke in hot environments. The medication also induces drowsiness, an effect exacerbated by the consumption of alcohol.

Pharmacology
Mechanism of action
Glycopyrronium competitively blocks muscarinic receptors, thus inhibiting cholinergic transmission.

Pharmacokinetics
Glycopyrronium bromide affects the gastrointestinal tracts, liver and kidney but has a very limited effect on the brain and the central nervous system. In horse studies, after a single intravenous infusion, the observed tendencies of glycopyrronium followed a tri-exponential equation, by rapid disappearance from the blood followed by a prolonged terminal phase. Excretion was mainly in urine and in the form of an unchanged drug. Glycopyrronium has a relatively slow diffusion rate, and in a standard comparison to atropine, is more resistant to penetration through the blood-brain barrier and placenta.

Research
It has been studied in asthma.

References
External links
"Glycopyrronium bromide". Drug Information Portal. U.S. National Library of Medicine.
"Glycopyrronium". Drug Information Portal. U.S. National Library of Medicine.