Drug Guide
Macimorelin Acetate
Classification
Therapeutic: Diagnostic agent for adult growth hormone deficiency
Pharmacological: Growth hormone secretagogue
FDA Approved Indications
- Adult growth hormone deficiency (GH deficiency) diagnosis
Mechanism of Action
Macimorelin mimics ghrelin and binds to the growth hormone secretagogue receptor, stimulating the release of endogenous growth hormone, which is measured to assess GH secretory capacity.
Dosage and Administration
Adult: Hydrochloride 0.5 mg/kg orally once, approximately 1 hour before testing.
Pediatric: Not approved for pediatric use.
Geriatric: No specific dosage adjustments; caution recommended due to potential increased sensitivity.
Renal Impairment: No specific dosage adjustments recommended.
Hepatic Impairment: No specific dosage recommendations available.
Pharmacokinetics
Absorption: Rapid absorption after oral administration.
Distribution: Not extensively detailed, suspected to be limited due to small molecule.
Metabolism: Metabolized in the liver.
Excretion: Primarily excreted via urine.
Half Life: Approximately 0.5-1 hours.
Contraindications
- Known hypersensitivity to macimorelin or any of its components.
- Patients with active malignancy or at risk of GH-related tumors.
Precautions
- Use cautiously in patients with cardiovascular disease, diabetes, or other metabolic conditions.
- Monitor for adverse reactions during testing.
Adverse Reactions - Common
- Nausea (Reported but uncommon.)
- Headache (Reported but uncommon.)
Adverse Reactions - Serious
- Hypertension or hypotension during procedure (Rare.)
- Allergic reactions including rash, swelling, difficulty breathing (Rare.)
Drug-Drug Interactions
- CYP3A4 inhibitors or inducers may alter metabolism.
Drug-Food Interactions
- Avoid high-fat meals around dosing time to ensure optimal absorption.
Drug-Herb Interactions
- Limited data; caution advised with herbal supplements.
Nursing Implications
Assessment: Assess contraindications, allergy history, and baseline vital signs.
Diagnoses:
- Risk for adverse reactions,
Implementation: Administer as directed, monitor for adverse effects, and ensure patient is fasting as recommended.
Evaluation: Monitor for correct GH response, adverse reactions, and patient’s tolerability.
Patient/Family Teaching
- Inform patient about the purpose of the test and possible side effects.
- Advise fasting for at least 2 hours before and after administration.
- Report any unusual symptoms such as allergic reactions or severe headache.
Special Considerations
Black Box Warnings:
- None specifically for macimorelin.
Genetic Factors: No known genetic considerations affecting use.
Lab Test Interference: Potential interference with GH measurement; interpret results accordingly.
Overdose Management
Signs/Symptoms: Unlikely due to single dose; watch for hypersensitivity or adverse reactions.
Treatment: Supportive care, symptomatic management, no specific antidote.
Storage and Handling
Storage: Store at room temperature away from light and moisture.
Stability: Stable under recommended storage conditions for the duration of shelf life.