ROBINUL FORTE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ROBINUL FORTE (ROBINUL FORTE).
Glycopyrrolate is a quaternary ammonium anticholinergic agent that competitively inhibits muscarinic acetylcholine receptors (M1, M2, M3) at postganglionic parasympathetic effector sites, reducing gastrointestinal motility, salivary secretion, and gastric acid secretion.
| Metabolism | Minimal hepatic metabolism; primarily excreted unchanged in urine and bile. |
| Excretion | Renal (approx. 50-70% unchanged) and biliary/fecal (approx. 30-50% as unchanged drug and metabolites). |
| Half-life | Terminal elimination half-life is approximately 2-4 hours in healthy adults; may be prolonged in elderly or renally impaired patients, requiring dose adjustment. |
| Protein binding | Low protein binding, approximately 15-25%, primarily to albumin. |
| Volume of Distribution | Approximately 1-2 L/kg, indicating extensive extravascular distribution (e.g., tissues including GI tract). |
| Bioavailability | Oral: 10-25% (variable due to first-pass metabolism); IM: near-complete (approximately 100% relative to IV). |
| Onset of Action | Oral: 30-60 minutes; IM: 15-30 minutes; IV: 2-5 minutes. |
| Duration of Action | Oral: 4-6 hours; IM: 4-6 hours; IV: 2-4 hours. Anticholinergic effects may persist longer, especially in GI motility inhibition. |
1-2 mg orally twice daily; may be increased to 1-2 mg three times daily if needed. Maximum dose: 4 mg daily.
| Dosage form | TABLET |
| Renal impairment | No specific guidelines; use with caution in severe renal impairment (CrCl <30 mL/min). |
| Liver impairment | No specific guidelines; use with caution in severe hepatic impairment (Child-Pugh C). |
| Pediatric use | Not approved for use in children under 12 years; for children 12 years and older, same dosing as adults. |
| Geriatric use | Initiate at lower dose (1 mg once or twice daily) due to increased anticholinergic sensitivity; monitor for cognitive impairment and urinary retention. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ROBINUL FORTE (ROBINUL FORTE).
| Breastfeeding | Glycopyrrolate is excreted into breast milk in very low amounts due to its quaternary ammonium structure (poor lipid solubility and high ionization). The M/P ratio is estimated to be <0.1 (likely negligible). It is considered compatible with breastfeeding, but caution is advised in infants with conditions exacerbated by anticholinergic effects (e.g., pyloric stenosis). Monitor infant for unusual drowsiness, constipation, or feeding difficulties. |
| Teratogenic Risk | Glycopyrrolate (ROBINUL FORTE) is a quaternary ammonium anticholinergic with minimal placental transfer. Animal studies show no teratogenicity at clinically relevant doses. First trimester: Limited human data, but theoretical low risk due to poor placental penetration. Second/third trimester: No known fetal malformations; may cause transient fetal tachycardia or decreased GI motility if high doses used. Overall, classified as FDA Pregnancy Category B (pre-2015) and generally considered low risk. |
■ FDA Black Box Warning
None
| Serious Effects |
["Hypersensitivity to glycopyrrolate or any component","Narrow-angle glaucoma","Obstructive uropathy (e.g., bladder neck obstruction due to prostatic hypertrophy)","Obstructive gastrointestinal disease (e.g., pyloric stenosis, achalasia)","Paralytic ileus, intestinal atony (especially in elderly or debilitated patients)","Severe ulcerative colitis or megacolon","Myasthenia gravis (unless used to reduce muscarinic side effects of anticholinesterase agents)","Tachycardia or any tachycardia-related condition","Hemodynamic instability (e.g., acute hemorrhage)"]
| Precautions | ["May cause heat prostration due to inhibition of sweating in high ambient temperatures","Caution in patients with glaucoma (narrow-angle), pyloric obstruction, prostatic hypertrophy, or urinary retention","May cause drowsiness or blurred vision; caution when driving or operating machinery","Use with caution in patients with coronary artery disease, congestive heart failure, arrhythmias, or hypertension","May decrease gastric motility in patients with gastric stasis"] |
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| Fetal Monitoring | Maternal: Monitor heart rate and blood pressure for anticholinergic effects; in high doses, assess for urinary retention or constipation. Fetal/neonatal: No specific monitoring required with standard doses; if used near term, observe neonate for transient tachycardia or meconium ileus (rare). |
| Fertility Effects | No adverse effects on fertility reported in animal or human studies. Anticholinergic effects do not impact ovulation or spermatogenesis at therapeutic doses. |