GLYRX-PF
Clinical safety rating: caution
Comprehensive clinical and safety monograph for GLYRX-PF (GLYRX-PF).
Glycopyrrolate is a quaternary ammonium anticholinergic that inhibits muscarinic acetylcholine receptors, thereby reducing salivary secretion and blocking vagally mediated bronchoconstriction.
| Metabolism | Glycopyrrolate is minimally metabolized via hydrolysis and conjugation in liver and plasma; undergoes renal excretion (predominantly unchanged). |
| Excretion | Primarily renal excretion of unchanged drug (70-80%) and metabolites; minor biliary excretion (<10%). |
| Half-life | Terminal elimination half-life of 4-6 hours; prolonged to 10-12 hours in renal impairment. |
| Protein binding | 30-40% bound to albumin. |
| Volume of Distribution | 0.7-1.2 L/kg, indicating distribution into total body water. |
| Bioavailability | Intravenous: 100%; intramuscular: 100% (with rapid absorption). |
| Onset of Action | Intravenous: 30-60 seconds; intramuscular: 3-5 minutes. |
| Duration of Action | 10-20 minutes following IV; 20-30 minutes following IM; dose-dependent. |
Intravenous: 1 mg/kg of ideal body weight for 2 minutes, repeated in 2 hours if required; thereafter every 4 hours as needed.
| Dosage form | SOLUTION |
| Renal impairment | No dosage adjustment required for renal impairment. |
| Liver impairment | No specific guidelines; use with caution in severe hepatic impairment due to risk of prolonged neuromuscular blockade. |
| Pediatric use | Intravenous: 0.02-0.05 mg/kg/dose given over 5-10 seconds; repeat doses of 0.01 mg/kg may be given every 30-60 minutes as needed. |
| Geriatric use | Dose reduction to 0.5-0.6 mg/kg ideal body weight may be necessary due to prolonged elimination and increased sensitivity. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for GLYRX-PF (GLYRX-PF).
| Breastfeeding | Glycopyrrolate is excreted into breast milk in small amounts; the M/P ratio is not established. Due to potential anticholinergic effects in the infant (e.g., decreased gastric motility), caution is advised. Consider alternative agents, especially in preterm or sensitive infants. |
| Teratogenic Risk | Glycopyrrolate (GLYRX-PF) is an anticholinergic agent. Animal studies have not shown teratogenic effects, but no adequate human studies exist. It crosses the placenta. In the first trimester, risk cannot be excluded. In the second and third trimesters, use only if clearly needed as anticholinergics may cause fetal tachycardia or meconium ileus. |
■ FDA Black Box Warning
Not for acute episodes of bronchospasm or acutely deteriorating COPD; may cause paradoxical bronchospasm which can be life-threatening.
| Serious Effects |
["Hypersensitivity to glycopyrrolate or any ingredient","Pre-existing narrow-angle glaucoma","Urinary retention","Gastrointestinal obstruction (e.g., pyloric stenosis)","Myasthenia gravis (relative, caution advised)"]
| Precautions | ["Immediate hypersensitivity reactions (angioedema, urticaria)","Paradoxical bronchospasm","Worsening of narrow-angle glaucoma","Urinary retention (especially in patients with prostatic hyperplasia)","Anticholinergic effects (dry mouth, constipation, blurred vision)"] |
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| Fetal Monitoring | Monitor maternal heart rate and blood pressure, as anticholinergic effects may cause tachycardia and hypertension. Fetal monitoring is recommended if used near term due to risk of fetal tachycardia. Assess for signs of neonatal anticholinergic effects (e.g., tachycardia, ileus) post-delivery. |
| Fertility Effects | No studies on human fertility. In animal studies, high doses of glycopyrrolate did not impair fertility. Theoretical concern: anticholinergic effects may alter cervical mucus or fallopian tube motility, but clinical significance unknown. |