Drug Interactions between denosumab 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.

MONITOR: Concomitant use of immunosuppressive or myelosuppressive agents with denosumab may increase the risk of serious infections. Denosumab binds to and inhibits the receptor activator of nuclear factor kappa-B ligand (RANKL), which is expressed on activated T and B lymphocytes and in lymph nodes. Thus, denosumab alone may increase the risk of infections. In a clinical trial of over 7800 women with postmenopausal osteoporosis, the incidence of nonfatal serious infections was 3.3% in the placebo group and 4.0% in the denosumab group. Specifically, hospitalizations due to skin infections including erysipelas and cellulitis (<0.1% placebo vs. 0.4% denosumab) and serious infections in the abdomen (0.7% placebo vs. 0.9% denosumab), urinary tract (0.5% placebo vs. 0.7% denosumab), and ear (0.0% placebo vs. 0.1% denosumab) were reported. Endocarditis was reported in no placebo patients and 3 denosumab-treated patients. There was no difference in the incidence of opportunistic infections or infections resulting in death between the placebo and denosumab groups. The overall incidence of infections was also similar between the two groups.

MANAGEMENT: Caution is advised if denosumab must be used in combination with immuno- or myelosuppressive agents. Patients should be advised to contact their physician if they develop signs and symptoms of infection such as fever, chills, diarrhea, sore throat, muscle aches, shortness of breath, blood in phlegm, weight loss, red or inflamed skin, body sores, and pain or burning during urination. The need for continued denosumab therapy should be assessed when serious infections occur during treatment.