FDA approved Arikayce (amikacin liposomal inhalation suspension) recently for patients with Mycobacterium-avium complex infections, not responding to conventional treatment.
Boxed warning with Arikayce includes hypersensitivity pneumonitis, bronchospasm, hemoptysis and exacerbation of the underlying chronic lung disease. Other side effects include dysphonia, cough, ototoxicity, upper airway irritation, fatigue, nausea, diarrhea and myalgias.
Safety and efficacy of Arikayce
The safety and efficacy of the drug were demonstrated in a randomized controlled clinical trial. Patients with mycobacterium avium complex were divided into two groups.
One group of patients received Arikayce via nebulization in addition to the standard treatment, while the other group was given the standard treatment only.
At month six, 29% of patients who received Arikayce had sputum culture negative in comparison to only 9% who received standard treatment.
Mycobacterium Avium complex infections
Mycobacterium Avium complex refers to infections of the either of the two nontuberculous mycobacterial species, M. vium or M.intracellulare.
How is Mycobacterium Avium infection transmitted?
Mycobacterium avium complex is ubiquitous in the environment – water and soil. It is usually transmitted through inhalation. Person to person transmission is minimal and therefore isolation of the patient is not usually required.
The strongest risk factor is a low immunity
The strongest risk factor for acquiring MAC infections is low immunity especially HIV infections with AIDS as the CD4 cell counts decline below 50 cells/mm3. Other risk factors include the use of an indoor swimming pool, previous bronchoscopy, repeated consumption of raw or cooked fish or shellfish.
Patients can have disseminated infections, a localized disease like lymphadenitis, and pulmonary infections.
Current treatment regimen for Mycobacterium Avium
The current treatment regimen for the treatment of MAC infections include clarithromycin or azithromycin and ethambutol. Rifabutin may be added as a third line agent. Adverse effects of these drugs include gastrointestinal intolerance and deranged liver function tests.
Since mortality in patients with HIV infections and immunocompromised state is already high, resistant MAC infections add on to the disease burden. The addition of this latest drug might improve outcomes in patients with resistant MAC infections.