Tigecycline Clearance in Older Adults
Tigecycline clearance decreases with age. In patients over 65 years, the clearance is about 20% lower than in younger adults (18-64 years), leading to higher drug exposure (AUC increased by roughly 30%). This stems from age-related declines in renal and hepatic function, though tigecycline dosing remains unchanged across adults.[1][2]
Dose Adjustments for Age
No specific dose adjustments are needed for elderly patients. The standard IV dose—100 mg loading, then 50 mg every 12 hours—applies regardless of age, as the pharmacokinetic changes do not exceed safety margins in trials.[1][3]
Key PK Parameters by Age Group
| Age Group | Clearance (L/h) | Half-Life (h) | AUC Increase vs. Young Adults |
|-----------|-----------------|---------------|-------------------------------|
| 18-64 years | ~0.85 | ~27-42 | Baseline |
| ≥65 years | ~0.68 | ~33-57 | ~30% |
Data from population PK analyses; half-life prolongation ties to slower elimination.[2][4]
Impact on Special Populations
In elderly with comorbidities (e.g., mild-moderate renal/hepatic impairment), exposure rises further but stays within therapeutic range without adjustment. Pediatric PK differs—no age-specific tigecycline data overlaps with geriatrics, as approval is adult-only.[1][5]
Clinical Implications and Monitoring
Higher exposure in older patients raises infection site concentrations but may increase nausea or mortality risk seen in some tigecycline trials (unrelated to age directly). Monitor for superinfections and adjust for obesity or critical illness, which interact with age effects.[3][6]
Sources:
[1] [Tygacil FDA Label]
[2] [Clin Pharmacokinet 2006]
[3] [Drug Saf 2009]
[4] [J Antimicrob Chemother 2009]
[5] [DrugPatentWatch.com - Tygacil PK Summary]
[6] [Clin Infect Dis 2013]