PYLORI-CHEK BREATH TEST
Clinical safety rating: caution
Comprehensive clinical and safety monograph for PYLORI-CHEK BREATH TEST (PYLORI-CHEK BREATH TEST).
Urea labeled with 13C is hydrolyzed by urease enzyme produced by Helicobacter pylori, producing 13CO2 which is exhaled and detected in breath.
| Metabolism | Urea is hydrolyzed by bacterial urease; no significant human metabolism. |
| Excretion | 13C-urea is excreted renally as intact urea (approximately 85%) and as 13CO2 in breath (approximately 15%). Fecal elimination is negligible. In renal impairment, breath 13CO2 excretion may increase as renal clearance decreases. |
| Half-life | The elimination half-life of 13C-urea is approximately 0.5–1 hour in patients with normal renal function, reflecting rapid renal clearance. In severe renal impairment, half-life may be prolonged up to 7–10 hours. |
| Protein binding | 13C-urea exhibits negligible protein binding (<5%), primarily to albumin and other plasma proteins, but this is clinically insignificant. |
| Volume of Distribution | The apparent volume of distribution of 13C-urea is approximately 0.5–0.7 L/kg, approximating total body water. This reflects distribution throughout intra- and extracellular fluid compartments. |
| Bioavailability | Oral bioavailability of 13C-urea is essentially 100% due to complete absorption from the gastrointestinal tract. However, the fraction that reaches systemic circulation unchanged is approximately 85–90% following first-pass metabolism to 13CO2 by gastric urease and hepatic arginase. |
| Onset of Action | After oral administration of the 13C-urea solution, detectable 13CO2 in breath appears within 10–20 minutes. The peak 13CO2 enrichment occurs at 30–45 minutes post-dose, corresponding to bacterial urease activity in the stomach. |
| Duration of Action | The rise in breath 13CO2 persists for approximately 60–90 minutes post-dose in infected patients, with resolution to baseline by 2–4 hours. The test is typically completed within 60 minutes. |
Adults: 75 mg of 13C-urea dissolved in 75 mL of water, administered orally as a single dose. Breath samples collected at baseline and 30 minutes post-dose.
| Dosage form | FOR SOLUTION |
| Renal impairment | No dose adjustment required for renal impairment as the drug is a diagnostic agent with minimal systemic absorption. |
| Liver impairment | No dose adjustment required for hepatic impairment. |
| Pediatric use | Children: weight-based dosing of 50 mg of 13C-urea for body weight < 20 kg, and 75 mg for body weight ≥ 20 kg, dissolved in water and administered orally. Breath samples collected as in adults. |
| Geriatric use | No specific dose adjustment recommended; use same dosing as for adults. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for PYLORI-CHEK BREATH TEST (PYLORI-CHEK BREATH TEST).
| Breastfeeding | Excretion into human milk is unknown but unlikely due to minimal systemic absorption. M/P ratio not available. Caution is advised; use only if essential. |
| Teratogenic Risk | PYLORI-CHEK BREATH TEST is a non-radioactive diagnostic agent using 13C-urea. No fetal risk is expected due to lack of systemic absorption; the compound is not teratogenic in standard animal studies. Nonetheless, it should be used during pregnancy only if clearly needed. |
| Fetal Monitoring |
■ FDA Black Box Warning
None
| Serious Effects |
["Hypersensitivity to any component of the test kit","Patients with severe renal impairment (due to urea component)"]
| Precautions | ["Not for use in patients with prior gastrectomy or gastric bypass","May yield false negatives if patient has recently taken antibiotics, proton pump inhibitors, or bismuth compounds","Ensure patient has fasted; test accuracy requires proper preparation"] |
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| No specific monitoring required; ensure proper breath collection technique to avoid inaccurate results. |
| Fertility Effects | No known effects on fertility based on available data. |