Macrilen, Macimorelin

Macimorelin is used for the diagnosis of adult growth hormone (GH) deficiency.

Macimorelin is available under the following different brand names: Macrilen.

Dosages of Macimorelin:

Dosage Forms and Strengths

Granules for Oral Solution

• 60mg/packet (0.5mg/mL following reconstitution)

Dosage Considerations – Should be Given as Follows:

Growth Hormone Deficiency

• Indicated for diagnosis of adult growth hormone (GH) deficiency
• 0.5 mg/kg orally as a single dose after fasting for at least 8 hours
• Recommendations before macimorelin use:
• Sufficient washout time of drugs that are known to prolong the QT interval before administration of macimorelin is recommended
• Avoid concomitant use of with drugs that prolong the QT interval (e.g., antipsychotic medications [e.g., chlorpromazine, haloperidol, thioridazine, ziprasidone]), antibiotics [e.g., moxifloxacin], class 1A antiarrhythmic medications [e.g., quinidine, procainamide], and class III antiarrhythmic medications [e.g., amiodarone, sotalol], any other medications known to prolong the QT interval)
• Discontinue strong CYP3A4 inducers (e.g., carbamazepine, enzalutamide, mitotane, phenytoin, rifampin, St. John’s wort, bosentan, efavirenz, etravirine, modafinil, armodafinil, rufinamide)
• Discontinue GH therapy at least 1 week before macimorelin administration
• Avoid concomitant use with drugs known to affect pituitary GH secretion
• For patients with deficiencies in sex hormones, thyroid hormone, and/or glucocorticoid, adequately replace each of the missing hormones
• Ensure patient has fasted for at least 8 hours

Dosing Considerations

Clinical studies have established that a maximally stimulated serum GH level less than 2.8 ng/mL (i.e., at the 30-, 45-, 60- and 90-minute time points) following macimorelin administration confirms the presence of adult GH deficiency

Limitation of use

• Safety and diagnostic performance have not been established with BMI greater than 40 kg/m²
• Safety and efficacy not established in pediatric patients

Common side effects of macimorelin include:

• Changes in taste
• Dizziness
• Headache
• Fatigue
• Nausea
• Hunger
• Diarrhea
• Upper respiratory tract infection
• Feeling hot
• Excessive sweating
• Runny or stuffy nose
• Slow heart rate

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Macimorelin has no listed severe interactions with other drugs.
• Macimorelin has serious interactions with at least 177 different drugs.
• Moderate interactions of macimorelin include:
  • cenobamate
  • elagolix
  • encorafenib
  • fedratinib
  • stiripentol
  • tazemetostat
  • tecovirimat
• Macimorelin has no listed mild interactions with other drugs.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

Warnings

• This medication contains macimorelin. Do not take Macrilen if you are allergic to macimorelin or any ingredients contained in this drug.
• Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.

Contraindications

• None

Effects of Drug Abuse

• No information available

Short-Term Effects

• See "What Are Side Effects Associated with Using Macimorelin?”

Long-Term Effects

• See "What Are Side Effects Associated with Using Macimorelin?”

Cautions

• QT prolongation may occur; macimorelin caused an increase of approximately 11 millisecconds in the corrected QT (QTc) interval; avoid concomitant use of macimorelin with drugs that are known to cause QT prolongation
• Potential for false-negative test results in recent-onset hypothalamic disease
• Adult growth hormone (GH) deficiency caused by a hypothalamic lesion may not be detected early in the disease process
• Macimorelin acts downstream from the hypothalamus and macimorelin-stimulated release of stored GH reserves from the anterior pituitary could produce a false-negative result early when the lesion involves the hypothalamus
• Repeat testing should be considered

Drug interactions overview

• Coadministration with drugs that prolong the QT interval may lead to the development of torsade de pointes-type ventricular tachycardia
• Drugs affecting growth hormone release
• Coadministration with drugs affecting GH release may impact the accuracy of the macimorelin diagnostic test; these drugs include the following:
• Drugs that directly affect the pituitary secretion of GH (eg, somatostatin, insulin, glucocorticoids, and cyclooxygenase inhibitors [e.g., aspirin, indomethacin])
• Drugs that may transiently elevate GH concentrations (e.g., clonidine, levodopa, insulin)
• Drugs that may blunt the GH response to macimorelin (e.g., muscarinic antagonists [atropine], antithyroid medication [propylthiouracil], GH products)
• Discontinue GH products at least 1 week before administering the diagnostic test
• Strong CYP3A4 inducers
• Concomitant use of strong CYP3A4 inducers can decrease macimorelin plasma levels significantly and potentially lead to a false-positive result
• Discontinue strong CYP3A4 inducers; allow enough time for a washout of CYP3A4 inducers before test

Pregnancy and Lactation

• No data are available regarding the use of macimorelin in pregnant women to inform a drug-associated risk for adverse developmental outcomes. Animal reproduction studies have not been conducted Macimorelin is indicated as a single dose, which limits the risk of adverse developmental outcomes from macimorelin exposure. Consult your doctor.
• Data are not available on the presence of macimorelin in human or animal milk, the effects on the breastfed infant, or the effects on milk production. The developmental and health benefits of breastfeeding should be considered along with the clinical need for macimorelin and any potential adverse effects on the breastfed infant from macimorelin or the underlying maternal condition.