Minimum effective regimen

Theoretical probability of tumor response vs. the cumulative area under the concenlralion-vs.-time curve (cAUC). The therapeutic index (TI) is defined by the minimum effective regimen (MER) and maximum tolerated regimen (MTR) as determined by the cAUC. The MER is defined by the cAUC where a 95% probability exists of having one or more successes if the drug is at least 20% effective. 

A designed dosage regimen allows prediction to be made of the maximum desirable and minimum effective steady-state plasma drug concentrations ... 

When the acute episode has been controlled and the clinical state stabilized, an attempt should be made to taper down the mood stabilizer regimen to the minimum effective... 

For treatment of endocarditis due to penicillin-susceptible staphylococci (minimum inhibitory concentration <0.1 mcg/mL), aqueous crystalline penicillin C sodium (Table 109-4, first regimen) can be used for 4 to 6 wk instead of nafcillin or oxacillin. Shorter antibiotic courses have been effective in some drug addicts with right-sided endocarditis due to Staphylococcus aureus (see text). See text for comments on use of rifampin. 

Patients with a small population of bacteria (i.e., with tuberculoid disease) should be treated with dapsone, 100 mg daily, plus rifampin, 600 mg once monthly fora minimum of 6 months. The regimen is repeated if relapse occurs. Single-dose multidrug therapy with rifampin (600 mg), ofloxacin (400 mg), or minocycline (100 mg) also may be as effective. 

In 9 HIV-positive patients on a stable regimen containing indinavir (mostly 800 mg every 8 hours), smoking a cannabis cigarette (3.95% tetrahydrocannabinol) three times a day before meals for 14 days resulted in a median 14% decrease in AUC and maximum level and a 34% decrease in minimum indinavir level. However, only the change in maximum level was statistically significant. Similarly, dronabinol 2.5 mg three times daily for 14 days had no significant effect on indinavir pharmacokinetics. ... 

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