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. |
| Molecular Weight | 234.34 |
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 | Limited data; use only if clearly needed. Animal studies not available. |
| 2nd trimester | No well-controlled studies; use if benefit outweighs risk. |
| 3rd trimester | May cause fetal respiratory depression or bradycardia if used near term; avoid during labor. |
Clinical note
Comprehensive clinical and safety monograph for GLYRX-PF (GLYRX-PF).
| Placental transfer | Lidocaine crosses placenta by passive diffusion; fetal/maternal ratio ~0.5-0.7. |
| Breastfeeding | Excretion into breast milk unknown; caution as other local anesthetics are excreted in small amounts. Use lowest effective dose. |
| Lactation Rating |
■ 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 lidocaine or amide anestheticsSevere heart blockUntreated sinus bradycardiaAdams-Stokes syndromeSevere hypotensionKnown hypersensitivity to polyethylene glycol or sulfites
| 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) |
| Food/Dietary | No significant food interactions known. However, avoid alcohol or CNS depressants for 24 hours post-administration as they may potentiate sedation. |
Loading safety data…
| L3 - Limited data |
| 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. |
| 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. |
| Clinical Pearls | GLYRX-PF (glycopyrrolate) is an anticholinergic used to reduce salivation in patients undergoing anesthesia. Administer IV over 1-2 minutes; onset is 1 minute, peak effect at 2-3 minutes. May cause tachycardia; use cautiously in patients with coronary artery disease or heart failure. Not recommended for use in patients with glaucoma, myasthenia gravis, or gastrointestinal obstruction. |
| Patient Advice | This medication is used to reduce excessive salivation during surgery. · You may experience dry mouth, blurred vision, or difficulty urinating after receiving this drug. · Report any rapid heartbeat, eye pain, or severe constipation to your healthcare provider. · This drug is not for use at home; it is administered by healthcare professionals in a hospital setting. |