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Macimorelin

Generic name: macimorelin systemic

Brand names: Macrilen

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Packet, Oral:

Macrilen: 60 mg (1 ea) [contains saccharin sodium]

Pharmacology

Mechanism of Action

Stimulates GH release by activating GH secretagogue receptors in the pituitary and hypothalamus.

Pharmacokinetics/Pharmacodynamics

Metabolism

Hepatic via CYP3A4

Time to Peak

0.5 to 1.5 hours

Half-Life Elimination

4.1 hours

Use: Labeled Indications

Diagnostic use: Growth hormone deficiency: Diagnosis of adult growth hormone (GH) deficiency

Limitations of use: The safety and diagnostic performance has not been established for patients with BMI >40 kg/m2.

Contraindications

There are no contraindications listed in the manufacturer's labeling

Dosage and Administration

Dosing: Adult

Diagnostic use: Growth hormone deficiency: Oral:

≤40 kg/m2: 0.5 mg/kg as single dose

>40 kg/m2: Dose has not been established

Dosing: Geriatric

Refer to adult dosing.

Reconstitution

After determining dosage and number of pouches needed, dissolve entire contents of each pouch with 120 mL of water (final concentration equals 0.5 mg/1 mL). Stir solution gently for about 2 to 3 minutes (a small amount of undissolved particles will remain). Transfer volume needed for dose using a syringe (without needle) graduated in mL into a drinking glass.

Administration

Oral: Patient must drink entire dose within 30 seconds after fasting for at least 8 hours.

Storage

Store pouches under refrigeration at 2°C to 8°C (36°F to 46°F). Solution must be used within 30 minutes after preparation. Discard unused portion.

Drug Interactions

Aspirin: May diminish the diagnostic effect of Macimorelin. Avoid combination

Atropine (Systemic): May diminish the diagnostic effect of Macimorelin. Avoid combination

Bosentan: May diminish the diagnostic effect of Macimorelin. Monitor therapy

CloNIDine: May diminish the diagnostic effect of Macimorelin. Avoid combination

Corticosteroids (Systemic): May diminish the diagnostic effect of Macimorelin. Avoid combination

CYP3A4 Inducers (Moderate): May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

CYP3A4 Inducers (Strong): May decrease the serum concentration of Macimorelin. Avoid combination

Dabrafenib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Seek alternatives to the CYP3A4 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Consider therapy modification

Deferasirox: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Efavirenz: May diminish the diagnostic effect of Macimorelin. Monitor therapy

Erdafitinib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Etravirine: May diminish the diagnostic effect of Macimorelin. Monitor therapy

Growth Hormone Products: May diminish the diagnostic effect of Macimorelin. Avoid combination

Haloperidol: QT-prolonging Agents (Indeterminate Risk - Avoid) may enhance the QTc-prolonging effect of Haloperidol. Monitor therapy

Insulins: May diminish the diagnostic effect of Macimorelin. Avoid combination

Ivosidenib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Levodopa-Containing Products: May diminish the diagnostic effect of Macimorelin. Avoid combination

Lorlatinib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Avoid concurrent use of lorlatinib with any CYP3A4 substrates for which a minimal decrease in serum concentrations of the CYP3A4 substrate could lead to therapeutic failure and serious clinical consequences. Consider therapy modification

Modafinil: May diminish the diagnostic effect of Macimorelin. Monitor therapy

Nonsteroidal Anti-Inflammatory Agents: May diminish the diagnostic effect of Macimorelin. Avoid combination

Propylthiouracil: May diminish the diagnostic effect of Macimorelin. Avoid combination

QT-prolonging Agents (Highest Risk): QT-prolonging Agents (Indeterminate Risk - Avoid) may enhance the QTc-prolonging effect of QT-prolonging Agents (Highest Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Monitor therapy

Sarilumab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Siltuximab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Somatostatin Analogs: May diminish the diagnostic effect of Macimorelin. Avoid combination

St John's Wort: May decrease the serum concentration of Macimorelin. Avoid combination

Tocilizumab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy

Adverse Reactions

1% to 10%:

Cardiovascular: Sinus bradycardia (1%)

Central nervous system: Dizziness (4%), fatigue (4%), headache (4%), feeling hot (1%)

Dermatologic: Hyperhidrosis (1%)

Gastrointestinal: Dysgeusia (5%), hunger (3%), nausea (3%), diarrhea (2%)

Respiratory: Upper respiratory tract infection (2%), nasopharyngitis (1%)

Frequency not defined:

Cardiovascular: Prolonged Q-T interval on ECG

Warnings/Precautions

Concerns related to adverse effects:

  • QT prolongation: Prolongation of the QTc interval (~11 msec) has been observed in clinical trials at doses 2- and 4-times the recommended dosage; avoid concurrent use with other agents known to prolong the QT interval.

Disease-related concerns:

  • Endocrine disorders: Correct deficiencies in sex or thyroid hormones and/or glucocorticoids prior to administration.
  • Hypothalamic disease: GH deficiency due to hypothalamic lesion may not be detected early in the disease process; macimorelin stimulates release of stored GH from the anterior pituitary, which may lead to false negative result. Repeat testing may be necessary.

Concurrent drug therapy issues:

  • Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Other warnings/precautions:

  • Appropriate use: Discontinue GH therapy at least 1 week prior to administration.

Monitoring Parameters

Serum GH at 30, 45, 60, and 90 minutes following administration

Pregnancy

Pregnancy Considerations

Animal reproduction studies have not been conducted.

Patient Education

  • Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
  • Have patient report immediately to prescriber fast heartbeat, abnormal heartbeat, or passing out (HCAHPS).
  • Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

Source: Wolters Kluwer Health. Last updated October 2, 2019.