Drugs for tuberculosis II (drugs for MAC)

1. Drugs for Mycobacterium Avium
Complex
S. Parasuraman, M.Pharm., Ph.D.,
Associate Professor, Faculty of Pharmacy,
AIMST University

2. Mycobacterium avium complex (MAC)
• Mycobacterium avium complex is a group of
mycobacteria comprising Mycobacterium intracellulare
and Mycobacterium avium causes pulmonary disease
and multifocal disease in immunocompromized
(HIV-AIDS) patients.
• These bacteria are ubiquitous in the environment and
can be encountered in water, food, and soil.

3. Pathogenic mycobacterial slow
and rapid growers (Runyon classification)
SLOW GROWERS
Runyon I: Photochromogens
• Mycobacterium kansasii
• Mycobacterium marinum
Runyon II: Scotochromogens
• Mycobacterium scrofulaceum
• Mycobacterium szulgai
• Mycobacterium gordonae
Runyon III: Nonchromogens
• Mycobacterium avium
complex
• Mycobacterium haemophilum
• Mycobacterium xenopi
RAPID GROWERS
• Runyon IV
• Mycobacterium fortuitum
complex
• Mycobacterium smegmatis
group
• Mycobacterium abscessus

4. Therapy of MAC Pulmonary Infection
• Mycobacterium avium complex is a group of
mycobacteria comprising Mycobacterium intracellulare
and Mycobacterium avium.
• Eradication of MAC has not been achieved by any drug or
regimen.
• In newly diagnosed patients with MAC pneumonia,
triple-drug therapy (rifamycin, ethambutol, and a
macrolide) is recommended.

5. Therapy of Disseminated M. avium Complex
• Disseminated MAC disease is caused by M. avium in
95% of patients.
• This is a disease of the immunocompromised patient,
especially with reduced cell-mediated immunity.

6. Prophylactic Therapy
• The goals of prophylactic therapy are to prevent the
development of disease during the time when a
patient’s CD4 count is low. Monotherapy with either
oral azithromycin 1200 mg once a week or
clarithromycin 500 mg twice a day is started when
patients present with a CD4 count below 50/mm3.
• Once the CD4 count is greater than 100 per mm3 for
3 months or longer, MAC prophylaxis should be
discontinued.

7. Definitive and Suppressive Therapy
• In patients with disease due to MAC, the goals of therapy
include suppression of symptoms. The infection itself is
not completely eradicated until immune reconstitution.
• Therapy is divided into initial therapy and chronic
suppressive therapy.
• Recommended therapy consists of a combination of
clarithromycin 500 mg twice a day with ethambutol 15
mg/kg daily, administered orally.
• Patients should be continued on suppressive therapy
until all three of the following criteria are met
– therapy duration of at least 12 months
– CD4 count greater than 100/mm3 for at least 6 months
– asymptomatic for MAC infection

8. Drugs active against atypical mycobacteria
• Mycobacterium tuberculosis overshadows most
other mycobacterial species, termed “atypical
mycobacteria or Nontuberculous mycobacteria
(NTM)”.
Reference: Gentry C. Atypical Mycobacteria. Pharmacotherapy Self-Assessment Program
5th edition [Internet].

9. Drugs active against atypical mycobacteria
• Atypical mycobacteria have caused many types of
infections, including pneumonia, lung abscess, pleural
space infection, lymphadenitis, skin and soft tissue
infection (including postoperative wound infection),
meningitis, gastrointestinal infection, joint space
infection, osteomyelitis, disseminated infection, and even
intravenous catheter-related infection.

10. Drugs active against atypical mycobacteria
• NTM Medication:
– Amikacin IV
– Amikacin
inhalation
– Azithromycin
– Bedaquiline
– Clarithromycin
– Cefoxitin
– Ciprofloxacin
– Clofazimine
– Doxycycline
– Ethambutol
– Imipenem/cilastin
Reference: Shulha JA, Escalante P, Wilson JW. Pharmacotherapy approaches in nontuberculous mycobacteria
infections. InMayo Clinic Proceedings 2019 Jun 1. Elsevier.
– Isoniazid
– Levofloxacin
– Linezolid
– Minocycline
– Moxifloxacin
– Rifampin
– Rifabutin
– Tedizolid
– Tigecycline
– Tobramycin IV
– Trimethoprim/sulfamethoxazole