Figure 2.

Target cumulative total dose using the generally recommended isotretinoin dosage regimen. The recommended target over a course of isotretinoin (ISO) therapy is a cumulative total dose of 120-150mg/kg. As each prescription of ISO under iPLEDGE is for up to 30 days, when prescribing ISO, 1 month=30 days. Using a 70kg patient as an example, the cumulative target ISO dose to reach 120mg/kg is 8400mg (120[mg] x 70[kg]=8400mg). Starting with 0.5mg/kg/day for the first 30 days calculates to a daily dose of 35mg/day over the first 30 days. This patient was started at 40mg/day for 30 days which delivered a total of 1200mg (40[mg] x 30[days]=1200mg) during that first month of ISO therapy. At the next monthly visit, the clinician chose to increase the dose to 1 mg/kg/day which calculates out to 70mg/day. For ease of administration with available ISO capsule sizes (10mg, 20mg, 30mg, 40mg), this patient was given 60mg/day (0.9mg/kg/day) which was continued at subsequent monthly visits as it was well tolerated and all iPLEDGE requirements were met each month. The patient was clear of their severe acne after 3 months of therapy; however, ISO was continued as the target cumulative ISO dose had not yet been reached. After four additional months at 60mg/day, the patient received 7200mg (60[mg] x30[days]=1800[mg/month] x4[months]=7200mg). Therefore, after 5 months of using the mg/kg/day as described above, the 8400mg cumulative total dose target was met (1200mg [first month] + 7200mg [next 4 months]=8400mg [total dose over course of therapy]). At this point, ISO therapy was stopped as the target cumulative total dose of ISO was reached.