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 inhalated forms. It is a synthetic quaternary ammonium.
It was developed by Sosei and licensed to Novartis in 2005. The cation, which is the active moiety, is called glycopyrronium or glycopyrrolate.
In June 2018, glycopyrronium was approved by the FDA to treat excessive underarm sweating, becoming the first drug developed specifically to reduce excessive sweating.

Medical uses

In anesthesia, glycopyrronium injection can be used as a before surgery in order to reduce salivary, tracheobronchial, and pharyngeal secretions, as well as decreasing the acidity of gastric secretion. It is also used in conjunction with neostigmine, a neuromuscular blocking reversal agent, to prevent neostigmine's 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, and Ménière's disease.
It decreases acid secretion in the stomach and so may be used for treating stomach ulcers, in combination with other medications.
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. 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

Since glycopyrronium reduces the body's sweating ability, it can even cause hyperthermia and heat stroke in hot environments. Dry mouth, difficulty urinating, headaches, diarrhea and constipation are also observed side effects of the medication. The medication also induces drowsiness or blurred vision, an effect exacerbated by the consumption of alcohol.

Pharmacology

Mechanism of action

Glycopyrronium 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.