How is the Hartford nomogram used?

Draw a single level 6–14 hours after first dose. Plot the time post-dose and concentration on the Hartford graph. The level falls in the q24h, q36h, or q48h zone—this determines subsequent dosing interval. A level above the q48h line requires conventional (synergistic) dosing or alternative antibiotic consideration.

What subsequent monitoring is needed with Hartford-guided dosing?

Check a single level 6–14 h after dose at 48–72 h to ensure the patient remains in the appropriate interval zone, especially if renal function changes. For extended courses (>7 days), audiometry may be considered in high-risk patients (prior ototoxicity, concomitant ototoxic drugs, chronic exposure).

Aminoglycoside Hartford Nomogram Interval Selector

Use the Hartford nomogram to determine gentamicin/tobramycin dosing interval (q24h, q36h, or q48h) based on a single post-distribution level drawn 6–14 hours after dose administration.

⚕ Clinical Disclaimer: These calculators are for educational and reference purposes only. Always verify results with qualified clinical judgment and current clinical guidelines. Do not use as a sole basis for medical decisions.

How It Works

Use the Hartford nomogram to determine gentamicin/tobramycin dosing interval (q24h, q36h, or q48h) based on a single post-distribution level drawn 6–14 hours after dose administration

Each component has a specific meaning:

Single post-distribution level drawn 6–14 hours after dose administration — The single post-distribution level drawn 6–14 hours after dose administration recorded for the scenario being assessed.

Note: Interpret the hartford nomogram result against the thresholds and context described above.

How to Use

Enter the single post-distribution level drawn 6–14 hours after dose administration for the scenario you are assessing. Use the Hartford nomogram to determine gentamicin/tobramycin dosing interval (q24h, q36h, or q48h) based on a single post-distribution level drawn 6–14 hours after dose administration. Use the hartford nomogram result to inform your calculation.

Related Calculators

Aminoglycoside EID

Medical Long-tail