How is isoniazid absorbed?
Absorption: Rapidly and completely absorbed from the GI tract after oral administration. INH also is absorbed readily after I.M. injection. Distribution: Distributed widely into body tissues and fluids, including ascitic, synovial, pleural, and cerebrospinal fluids; lungs and other organs; and sputum and saliva.
What is the pharmacokinetics of isoniazid?
Isonicotinyl hydrazine or isoniazid (INH) has been the mainstay of TB treatment and prevention in both adults and children. When given orally in the fasted state, INH is rapidly absorbed with the maximum concentration (Cmax) occurring 1–2 hours post-dose. Food delays and decreases the extent of absorption.
Where is isoniazid absorbed?
Isoniazid is almost completely absorbed from the gastrointestinal tract, and the recommended dose achieves therapeutic levels in all body tissues and fluids, including the CSF.
How does absorption affect bioavailability?
5.1 Definition. Absorption is the movement of drug from the site of drug administration to the systemic circulation. Bioavailability is the extent to which absorption occurs. In other words, bioavailability is the fraction of the administered drug that reaches the systemic circulation in the unchanged form.
What is isoniazid made of?
Preparation. Isoniazid is an isonicotinic acid derivative. It is manufactured using 4-cyanopyridine and hydrazine hydrate. In another method, isoniazid was claimed to have been made from citric acid starting material.
What medication route has the slowest absorption rate?
Subcutaneous (SC) The absoroption of subcutaneous injections is slower than that of IV route and it needs absorption similar to Intramuscular injection.
What route of drug absorption has the greatest bioavailability?
The intravenous route provides 100% absorption and bioavailability and is the least problematic of routes of administration.
What is the PK of isoniazid and ethambutol?
Wide variability is reported in the pharmacokinetics (PK) of isoniazid, pyrazinamide, and ethambutol [ 10 – 12 ], with factors such as age and HIV status and antiretroviral treatment (ART) possibly affecting TB drug concentrations [ 12 – 17 ].
What are the pharmacokinetics of isoniazid and pyrazinamide?
In this study we aimed to investigate the effect of standard of care plus nutritional supplementation versus standard care on the pharmacokinetics of isoniazid, pyrazinamide and ethambutol among sputum smear positive TB patients with and without HIV.
Which is responsible for metabolizing inh into isoniazid?
Acetylating enzymes, such as N-acetyltransferases present in the liver and small intestine, are responsible for metabolizing INH into acetyl-isoniazid. However, patients that consumed INH orally had significantly different INH blood concentrations, with rapid acetylators having a lower INH concentration than slow acetylators [ 13 ].
Are there any side effects to taking isoniazid?
Although isoniazid (INH) has been successful in treating Tuberculosis (TB) since its introduction in 1952, there has been continual reports of drug-associated hepatotoxicity in TB patients. These toxic side effects may reveal more about the recipient of the drug, than the drug itself.