Why Do You Inject Two Doses Of Emgality The First Month?

In our latest question and answer, our pharmacist explains why there is a loading dose of Emgality.

Question

I am just wondering something. Why do you need two shots of Emgality the first month, but only one every month thereafter?

Asked by George On Mar 29, 2023

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Mar 29, 2023
Last updated Jun 14, 2024

Key points

  • Emgality is a medication used for the preventive treatment of migraine headaches in adults and episodic cluster headaches.
  • When using Emgality for chronic migraine prevention, the recommended dosing is a loading dose of 240 mg (two injections of 120 mg each) followed by monthly injections of 120 mg to achieve a steady-state concentration of the drug in the bloodstream.
  • Steady-state refers to the point at which the amount of drug entering the body is equal to the amount being eliminated, and drug concentrations in the bloodstream remain constant over time.

Answer

Great question! Let's get right into it.

What Is Emgality?

Emgality (galcanezumab-gnlm) is a medication used for the prevention of migraine headaches in adults as well as for the treatment of episodic cluster headaches.

It belongs to a class of drugs called calcitonin gene-related peptide (CGRP) antagonists, which work by binding to a protein called calcitonin gene-related peptide (CGRP) and blocking its action.

CGRP is involved in the development of migraine headaches, so by blocking its action, Emgality can reduce the frequency and severity of migraine headaches.

Why Is There A Loading Dose For Emgality?

The recommended dosing for Emgality is 240 mg (two injections of 120 mg each) as a loading dose, followed by monthly injections of 120 mg. This is what you mentioned in your question when you asked about why you need to take two doses (i.e., injections) at one time during your first month of starting the drug.

Those two initial shots (which are given one right after the other) are a 'loading dose', which is necessary to achieve the steady-state concentration of the drug in the bloodstream.

Steady-state refers to the point at which the amount of drug entering the body is equal to the amount being eliminated. In other words, it is the point at which the drug concentration in the bloodstream remains constant over time.

Achieving steady-state is important for drugs that are given repeatedly, such as Emgality, because it ensures that the drug is consistently present in the body at therapeutic levels.

Without the loading dose, it may take several months of monthly injections to reach a steady state, resulting in delayed therapeutic effects and potentially increased risk of breakthrough migraines occurring.

It is important to note that the recommended dosing for Emgality is based on clinical trials and may vary depending on the individual's response to the drug. Always be sure to talk to your doctor about your medication if you have questions about dosing or before making any changes to your regimen.

Additional Notes From The Pharmacist

It is also important to note that the dosing for cluster headaches is different than the dosing for chronic migraine prevention.

The recommended dosage of Emality for cluster headaches is 300 mg (three consecutive subcutaneous injections of 100 mg each) at the onset of the cluster period, and then once monthly until the end of the cluster period.

As a final note here, a common question that I've received here at HelloPharmacist is whether or not you need to take a loading dose again if you've been on Emgality in the past, stopped it, and are restarting. The answer is yes, if you've been off Emgality for more than a month, you should restart dosing with a loading dose.

Final Words

Thanks so much for contacting us and feel free to do so again anytime!

References

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at [email protected]! You can also connect with Dr. Brian Staiger on LinkedIn.

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