Drug Interactions between macimorelin and moxifloxacin / triamcinolone

MONITOR CLOSELY: Concomitant administration of corticosteroids may potentiate the risk of tendinitis and tendon rupture associated with fluoroquinolone treatment. The mechanism is unknown. Tendinitis and tendon rupture have most frequently involved the Achilles tendon, although cases involving the rotator cuff (the shoulder), the hand, the biceps, and the thumb have also been reported. Some have required surgical repair or resulted in prolonged disability. Tendon rupture can occur during or up to several months after completion of fluoroquinolone therapy.

MANAGEMENT: Caution is recommended if fluoroquinolones are prescribed in combination with corticosteroids, particularly in patients with other concomitant risk factors (e.g., age over 60 years; recipient of kidney, heart, and/or lung transplant). Patients should be advised to stop taking the fluoroquinolone, avoid exercise and use of the affected area, and promptly contact their physician if they experience pain, swelling, or inflammation of a tendon. In general, fluoroquinolones should only be used to treat conditions that are proven or strongly suspected to be caused by bacteria and only if the benefits outweigh the risks.

GENERALLY AVOID: Macimorelin can cause prolongation of the QT interval. Theoretically, coadministration with other agents that can prolong the QT interval may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death. In a dedicated thorough QT study consisting of 60 healthy subjects, a mean baseline- and placebo-adjusted change in QTcF of 9.6 msec was observed 4 hours following administration of a supratherapeutic dose of macimorelin 2 mg/kg (4 times the recommended dose), which occurred after the mean maximum macimorelin plasma concentration (0.5 hour). A similar increase in the QTcF interval was also observed in a single-ascending dose study, which included three dose levels: 0.5 mg/kg; 1 mg/kg (2 times the recommended dose); and 2 mg/kg (4 times the recommended dose). All three doses levels produced a similar magnitude of QTcF prolongation as reported in the thorough QT study, suggesting an absence of dose-dependent changes. The mechanism for the observed QTcF prolongation is unknown. In general, the risk of an individual agent or a combination of agents causing ventricular arrhythmia in association with QT prolongation is largely unpredictable but may be increased by certain underlying risk factors such as congenital long QT syndrome, cardiac disease, and electrolyte disturbances (e.g., hypokalemia, hypomagnesemia). In addition, the extent of drug-induced QT prolongation is dependent on the particular drug(s) involved and dosage(s) of the drug(s).

MANAGEMENT: Coadministration of macimorelin with other drugs that can prolong the QT interval should generally be avoided. A sufficient washout period following discontinuation of these drugs is recommended prior to macimorelin administration. Patients treated with any medication that can cause QT prolongation should be advised to seek prompt medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, fainting, palpitation, irregular heart rhythm, shortness of breath, or syncope.

GENERALLY AVOID: Drugs that directly affect the pituitary secretion of growth hormone (e.g., somatostatin, insulin, glucocorticoids, cyclooxygenase inhibitors such as aspirin and nonsteroidal anti-inflammatory drugs) and drugs that may transiently elevate growth hormone levels (e.g., clonidine, levodopa, insulin) may impact the accuracy of the macimorelin diagnostic test.

MANAGEMENT: Concomitant use of macimorelin with drugs affecting growth hormone levels should generally be avoided. A sufficient washout period following discontinuation of these drugs is recommended prior to macimorelin administration.