Glycopyrronium Side Effects: What to Expect and When to Call Your Doctor

Glycopyrronium (glycopyrrolate) works by blocking muscarinic receptors throughout your body. This mechanism is responsible for its benefits — reduced secretions, improved airflow, less sweating — but it's also what causes its side effects. Because muscarinic receptors are widespread in the body, side effects can affect many organ systems.

Here's a plain-English breakdown of what to expect, and critically, which symptoms mean you should call your doctor or seek emergency care.

Most Common Side Effects of Glycopyrronium

These side effects are typical with anticholinergic medications and are experienced by many patients. They are generally dose-dependent — higher doses are more likely to cause them:

Dry mouth (xerostomia): One of the most frequently reported side effects. Glycopyrronium reduces salivary secretions — which is therapeutic for drooling and anesthesia prep, but uncomfortable for patients taking it for other indications. Sipping water frequently, chewing sugar-free gum, and using saliva substitutes can help.

Constipation: Glycopyrronium slows GI motility. Drink plenty of water, eat fiber-rich foods, and contact your doctor if constipation becomes severe or you develop abdominal pain.

Blurred vision: Anticholinergic effects can cause pupil dilation and impair near vision. Avoid driving or operating machinery if vision is significantly affected.

Difficulty urinating (urinary hesitancy): The medication relaxes bladder muscle tone, making it harder to start urination. Men with enlarged prostates are at higher risk. Tell your doctor if you have trouble urinating at all.

Nausea, diarrhea, or vomiting: Less common but reported, particularly with oral formulations. Taking oral glycopyrrolate on an empty stomach (1 hour before or 2 hours after a meal) as directed for Cuvposa may reduce GI upset.

Headache: Reported in clinical trials; usually mild and self-limiting.

Flushing and nasal congestion: Common, especially in children on Cuvposa. The skin can appear red (flushing) as the drug reduces sweating and alters skin blood flow.

Irritability (especially in children): A notable side effect in pediatric patients on oral glycopyrrolate. If your child becomes unusually irritable on this medication, notify your pediatric neurologist.

Topical Qbrexza: Formulation-Specific Side Effects

Patients using Qbrexza topical cloths typically experience fewer systemic side effects because absorption through the skin is lower than with oral formulations. The most common Qbrexza-specific side effects are:

Dry skin, burning or stinging at the application site

Erythema (skin redness) at the underarm

Dry mouth (from systemic absorption, though less common than with oral dosing)

Dilated pupils if the hands aren't washed thoroughly after application and touch the eyes

Important: Always wash hands thoroughly after applying Qbrexza. Avoid touching your eyes before washing hands. Pupil dilation from inadvertent eye contact can cause blurred vision, photosensitivity, and eye pain.

Serious Side Effects: When to Seek Immediate Help

The following are serious side effects requiring prompt medical attention:

Heat prostration / heat stroke: Glycopyrronium reduces sweating. In hot environments or during physical exertion, your body loses its ability to regulate temperature. This is the most dangerous side effect. Symptoms include very hot, dry skin, rapid heart rate, confusion, and loss of consciousness. Call 911 immediately.

Urinary retention: Complete inability to urinate is a medical emergency, particularly in men with enlarged prostates. Go to urgent care or the emergency room.

Acute angle-closure glaucoma: Sudden eye pain, redness, headache, nausea, and blurred vision with halos around lights — especially if you have risk factors for narrow-angle glaucoma. Call your eye doctor or go to the emergency room.

Rapid or irregular heartbeat (palpitations): Glycopyrronium can cause tachycardia at higher doses. If you notice a pounding or racing heart, particularly at rest, contact your healthcare provider or seek emergency care if severe.

Severe constipation or intestinal obstruction: Abdominal pain, distension, and absence of bowel movements for several days warrant a call to your doctor. Patients with colostomy or ileostomy: diarrhea may paradoxically signal obstruction — call your doctor.

Who Is at Higher Risk for Serious Side Effects?

Elderly patients: More sensitive to anticholinergic effects; at higher risk for confusion, constipation, and urinary retention.

Men with enlarged prostate (BPH): Higher risk for urinary retention.

People with narrow-angle glaucoma: Glycopyrronium is contraindicated. Use with extreme caution; should only be given with ophthalmologist guidance.

Children and people with Down syndrome or spastic conditions: These groups may have an exaggerated response to anticholinergic medications.

Tips to Manage Common Side Effects

Dry mouth: Sip water throughout the day; use sugar-free hard candy or gum; use saliva substitute products

Constipation: Increase fluid and fiber intake; ask your doctor about stool softeners

Heat sensitivity: Stay cool, avoid intense outdoor activity in heat, stay hydrated, wear lightweight clothing

Blurred vision: Avoid driving until you know how the medication affects your vision

For more on how other medications can worsen glycopyrronium side effects, read our post on glycopyrronium drug interactions.