Drug Calculations

Maintenance Dose Calculator

Ongoing dose rate that holds a steady-state drug level, from clearance.

Reviewed by Alex G, BSN, RN, CEN, CCRN, CMC, NREMT-P · From the Reference tab of the app

Turn on JavaScript to use this calculator, or open it in the web app.

Formula

Clearance * Concentration

How it is used

• Maintenance rate = clearance × target steady-state concentration (mg/h when clearance is in L/h and concentration in mg/L).
• It depends on clearance, so it is lowered in kidney or liver failure while the loading dose usually stays the same.
• Steady state still takes about five half-lives whatever the dose; check levels as the drug’s protocol directs.

Same formula as the app. Open it in the web app.

Related one-pagers

• Sleep Medicine and Chronic Lung Care3 · Low-dose maintenance-and-reliever (MART) · Daily low-dose ICS–LABA
• Vasopressors and InotropesNorepinephrine · Start 8–12 mcg/min; label maintenance 2–4; shock often needs more
• Mental Health: Meds and CommunicationLithium target (label): 0.8–1.2 mEq/L acute, 0.8–1.0 maintenance (many texts 0.6–1.2); draw 12 h post-dose.
• Acute Kidney InjuryPharmacist review: full loading doses, adjusted maintenance, drug levels; avoid morphine and NSAIDs

Drip cards with a dose ↔ mL/h converter

Related calculators

• Desired Over Have
• Drip Rate (drops/min)
• Half-Life
• Loading Dose
• mcg/kg/min to mL/hr
• Push-Dose Epinephrine
• Tablets or Capsules to Give
• Weight-Based Dose (mg/kg)

For education and exam preparation only. Follow your institution’s protocols. For education and exam preparation only. Verify results independently and follow your institution’s protocols. Not a substitute for clinical judgment.