About Acthar Gel Dosing

This information supports the use of the Acthar Dosing Calculator for H.P. Acthar® Gel (repository corticotropin injection). Acthar Gel is a long-acting formulation of adrenocorticotropic hormone (ACTH) indicated for the treatment of various inflammatory and autoimmune conditions. This includes infantile spasms, acute exacerbations of multiple sclerosis, rheumatoid arthritis, systemic lupus erythematosus, and others. The following sections provide a general overview of dosing principles, usage, and safety considerations. Always refer to the official prescribing information before making any clinical decisions.

Outputs Explained

The calculator provides several key outputs to support clinical workflow:

• Calculated Dose (Units): The specific dose in international units (U) based on the selected indication and patient parameters.
• Volume to Administer (mL): The corresponding volume of Acthar Gel (80 U/mL) to be drawn up for injection.
• Dosing Regimen: A summary of the recommended frequency and administration route (intramuscular or subcutaneous).
• Body Surface Area (BSA): For infantile spasms, the dose is based on BSA, which is calculated from the patient's height and weight.
• Supply Estimate: An optional calculation of the total number of 5 mL vials (400 U/vial) needed for a specified treatment duration.

How to Use the Calculator

To ensure accurate results, follow these steps when using the tool:

1. Select Indication: Choose the appropriate clinical indication from the dropdown menu. This is the most critical step, as dosing regimens vary significantly.
2. Enter Patient Data: If prompted, enter the patient's weight and height. These are required for the Body Surface Area (BSA) based dosing for infantile spasms.
3. Specify Treatment Duration (Optional): To estimate the required number of vials, enter the length of the planned treatment period and select whether it is in days or weeks.
4. Calculate and Review: Click the "Calculate Dose" button. The tool will display the recommended dose, volume, and regimen. Always cross-reference the output with the full Prescribing Information and apply clinical judgment.

Dosing Overview

Dosing for Acthar Gel is highly dependent on the condition being treated. The following is a summary of common regimens:

• Infantile Spasms: The recommended regimen is 150 U/m²/day, administered as two divided doses of 75 U/m² intramuscularly (IM) or subcutaneously (SQ) for 2 weeks. This is followed by a gradual dose taper to discontinue therapy.
• Multiple Sclerosis (Acute Exacerbations): The typical dose is 80-120 U daily via IM or SQ injection for a duration of 2-3 weeks.
• Rheumatic & Other Inflammatory Conditions: For conditions like rheumatoid arthritis, lupus, and symptomatic sarcoidosis, the dose is generally in the range of 40-80 U. The frequency varies from daily to every few days, depending on the specific indication and patient response. Therapy should be individualized and titrated to the lowest effective dose.

Switching Therapy

Switching a patient to or from Acthar Gel from other therapies (e.g., corticosteroids) requires careful medical supervision. Due to differences in mechanism of action and duration of effect, there is no direct dose equivalency. Any transition should involve a gradual taper of the previous medication while initiating Acthar Gel, with close monitoring for therapeutic response and adverse effects.

Missed Dose Protocol

If a dose of Acthar Gel is missed, the patient or caregiver should be instructed to administer it as soon as they remember. However, if it is almost time for the next scheduled dose, they should skip the missed dose and resume the regular dosing schedule. Instruct them not to administer a double dose to make up for a missed one. For specific guidance, patients should consult their healthcare provider.

Safety Alerts

Acthar Gel shares the same contraindications and potential adverse effects as other corticosteroids. Key safety considerations include:

• Increased risk of infection: Acthar can suppress the immune system, increasing susceptibility to new infections or exacerbating existing ones.
• Masking of infections: Its anti-inflammatory effects can mask the signs and symptoms of an ongoing infection.
• Cardiovascular effects: May cause elevation of blood pressure, salt and water retention, and hypokalemia. Monitor blood pressure and electrolytes.
• Gastrointestinal risks: Use with caution in patients with peptic ulcer disease, diverticulitis, or recent intestinal anastomoses.

Frequently Asked Questions (FAQ)

References

1. H.P. Acthar Gel - Prescribing Information. U.S. Food and Drug Administration (FDA). Accessed via DailyMed.
2. Acthar Gel (repository corticotropin injection) HCP Website. Mallinckrodt Pharmaceuticals.
3. Pellock JM, Hrachovy R, Shinnar S, et al. Infantile spasms: a U.S. consensus report. Epilepsia. 2010;51(10):2175-2189. doi:10.1111/j.1528-1167.2010.02519.x
4. Goodin DS, Frohman EM, Garmany GP Jr, et al. Disease modifying therapies in multiple sclerosis: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology and the MS Council for Clinical Practice Guidelines. Neurology. 2002;58(2):169-178. doi:10.1212/wnl.58.2.169