"The US Food and Drug Administration (FDA) is investigating the "rare but serious" risk for slowed or difficult breathing in children 17 and younger treated with the opioid analgesic tramadol.
"This risk may be increased in children tr"...
Rifampin inhibits DNA-dependent RNA polymerase activity in susceptible cells. Specifically, it interacts with bacterial RNA polymerase but does not inhibit the mammalian enzyme. This is the mechanism of action by which rifampin exerts its therapeutic effect. Rifampin cross-resistance has only been shown with other rifamycins.
In a study of 14 normal human adult males, peak blood levels of rifampin occurred 1 1/2 to 3 hours following oral administration of two RIFAMATE (rifampin and isoniazid) capsules. The peaks ranged from 6.9 to 14 mcg/mL with an average of 10 mcg/mL.
Isoniazid acts against actively growing tubercle bacilli.
After oral administration isoniazid produces peak blood levels within 1 to 2 hours which decline to 50% or less within 6 hours. It diffuses readily into all body fluids (cerebrospinal, pleural, and ascitic fluids), tissues, organs, and excreta (saliva, sputum, and feces). The drug also passes through the placental barrier and into milk in concentrations comparable to those in the plasma. From 50 to 70% of a dose of isoniazid is excreted in the urine in 24 hours.
Isoniazid is metabolized primarily by acetylation and dehydrazination. The rate of acetylation is genetically determined. Approximately 50% of Blacks and Caucasians are “slow inactivators”; the majority of Eskimos and Orientals are “rapid inactivators.”
The rate of acetylation does not significantly alter the effectiveness of isoniazid. However, slow acetylation may lead to higher blood levels of the drug, and thus an increase in toxic reactions.
Last reviewed on RxList: 2/24/2009
This monograph has been modified to include the generic and brand name in many instances.
Additional Rifamate Information
Rifamate - User Reviews
Rifamate User Reviews
Now you can gain knowledge and insight about a drug treatment with Patient Discussions.
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Find out what women really need.