How many half-lives for 97% drug clearance?

5 half-lives: 97% eliminated; 4 half-lives: 94%; 7 half-lives: 99.2%; 10 half-lives: 99.9%. For amiodarone (t½ 40-55 days), 97% washout takes approximately 200-275 days after the last dose.

When is precise drug washout calculation clinically important?

Drug washout timing is critical before: pregnancy in women on teratogenic drugs (methotrexate, leflunomide, thalidomide), MAOI to SSRI switches (serotonin syndrome prevention), initiation of live vaccines after immunosuppressants.

Drug Washout Calculator — Half-Lives to Clearance

Calculate time required to reach any desired residual drug concentration or functional washout (>95%, >99%, >99.9%) after discontinuation based on the drug's elimination half-life.

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Drug Washout Calculator — Half-Lives to Clearance

Frequently Asked Questions

How many half-lives for 97% drug clearance?

When is precise drug washout calculation clinically important?