TDM

Question 1

Situations where aminoglycoside extended interval dosing is not preferred

Answer 1

• CrCl <20
• Patients on RRT
• Patients with augmented renal clearance or altered volume of distribution
• Gram +ve infections
• HACEK endocarditis
• Bartonella spp. infections

Question 2

Initial dosing of aminoglycosides using extended interval dosing method

Answer 2

• Gentamicin & tobramycin: 7 mg/kg (5 mg/kg for less severe infections e.g. UTI)
• Amikacin 10-15 mg/kg

Use actual body weight or adjusted body weight for obese patients (ABW >30% above IBW)

Question 3

When to obtain the first level for aminoglycoside TDM for extended interval dosing method?

Answer 3

6-14 hours strictly