Table of Contents
Anti-TB Antibiotics
Causative agent: Mycobacterium Tuberculosis
First Line TB Drugs
RIPES or RESPIre
| MOA | Side effects | |
| Rifampin, Rifapentine, Rifabutin | Inhibit DNA-dependent RNA polymerase -Rifabutin is similar to rifampin, same MOA -Rifapentine is a long-acting anti-TB drug similar to Rifampin, same MOA |
–Hepatotoxic (Asymptomatic jaundice, high LFTs) –RED-orange urine, sweat, and tears. Rifampin cause urine, sweat, and tears to become RED-orange in color. This doesn’t harm the patient, but they need to know or they will panic. |
| INH (Isoniazid) | Interferes with the synthesis of mycolic acid components of the cell wall of mycobacterium. | –Hepatotoxic. -Can induce pyridoxine (Vit. B6) deficiency causing pellagra (peripheral neuropathy/neuritis, rash, anemia). That’s why you should give Vit B6 to patients taking INH |
| Pyrazinamide | unknown. Pyrazinamide is an analog of nicotinamide. |
–Hepatotoxic! -Gout! Inhibits uric acid secretion > increased levels of uric acid. |
| Ethambutol | unknown | -Ocular toxicity (decreased visual acuity, color vision loss, loss of central vision-central scotoma). Ask the patient to read fine newspaper print every day to check for this side effect and to report to you if they develop difficulty so. |
| Streptomycin (an aminoglycoside) | Binds to 30S ribosomal subunit to inhibit protein synthesis. | Vestibular & ototoxicity. |
Second Line TB Drugs
These are used when multiple antibiotics are needed for the treatment of multi-drug resistant TB
- Para-aminosalicylic acid
- Capreomycin sulfate
- Cycloserine
- Ethionamide
- Kanamycin (Aminoglycoside)
- Amikacin (Aminoglycoside)
- Quinolones such as levofloxacin
- Linezolid
- Bedaquiline (Approved in Dec 2012 for tx of MDR-TB)
Anti-Leprosy Antibiotics
Causative agent: Mycobacterium Leprae
Severe cases of leprosy disease should be treated with three drugs (rifampin, dapsone, clofazimine) for at least two years and until patients are AFB (acid-fast bacilli) negative. Less severe cases can be treated with two drugs (rifampin and dapsone) for six months.
| MOA | Common Uses | Side Effects | |
| Dapsone, Sulfoxone (both are sulfones) | PABA antagonist, similar MOA as sulfonamides. This results in blocking of dihydrofolate (DHF) synthesis. DHF is a precursor of tetrahydrofolate (TH4) which is necessary for making purines. This leads to inhibition of bacterial DNA synthesis. | Mycobacterium leprae. | -Skin rash, drug fever. -Bone marrow suppression; agranulocytosis – low neutrophils -Leprosy reaction |
| Rifampin | Inhibit DNA-dependent RNA polymerase | Rifampin treats both TB and leprosy. | See above. |
| Clofazimine | Binds to DNA. It also has anti-inflammatory actions that are helpful for treating leprosy reactions. | Mycobacterium leprae. It’s anti-inflammatory actions that are helpful for treating leprosy reactions. |
-Red and black skin discolorations. |
Resources:
Clinical microbiology made ridiculously simple.