aminosalicylic acid

Action and Spectrum

Actions and spectrum: 

Amino salicylic acid (also known as para-amino salicylic acid or PAS) is an antibiotic used in the treatment of tuberculosis. It works by inhibiting the growth of Mycobacterium tuberculosis, the bacteria responsible for tuberculosis. Amino salicylic acid is a bacteriostatic agent, which means that it slows down the growth of bacteria rather than killing them outright. 

Amino salicylic acid has a narrow spectrum of activity, and it is primarily effective against Mycobacterium tuberculosis. It is used in combination with the antibiotics to treat other infections caused by bacteria such as E. coli, Salmonella, and Shigella. However, its use in these infections is limited due to the availability of more effective antibiotics. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Hypersensitivity reactions: skin eruptions including infectious mononucleosis, exfoliative dermatitis, leucopenia, thrombocytopenia, jaundice, pericarditis, optic neuritis, Leoffler’s syndrome, reduced prothrombin, Fever, agranulocytosis, Coombs’  hemolytic anemia, hepatitis, hypoglycemia, encephalopathy, vasculitis 

GI intolerance by nausea, diarrhea, vomiting, and abdominal pain 

Crystalluria 

Black Box Warning

Black Box Warning: 

Amino salicylic acid can cause severe and life-threatening gastrointestinal toxicity, including bleeding, ulceration, and perforation in gastrointestinal toxicity hepatic toxicity and hypersensitivity reactions 

Contraindication / Caution

Contraindication/Caution: 

Contraindication: 

aminosalicylic acid is contraindicated in patients with a known hypersensitivity to aminosalicylic acid, sulfonamides, or any other ingredient in the medication. It is also contraindicated in patients with severe renal impairment or urinary tract obstruction. Patients with porphyria should also avoid aminosalicylic acid. Amino salicylic acid should not be used in pediatric patients under 6 years of age, as safety and effectiveness have not been established in this population.  

Caution: 

aminosalicylic acid (ASA) should be used under caution in patients with peptic ulcer disease or other gastrointestinal disorders, as it may cause gastrointestinal irritation or bleeding. ASA should also be used with caution in patients with liver or kidney disease, as it may affect the function of these organs. Patients with hypersensitivity to ASA or other salicylates should not use ASA. Additionally, ASA should be used with caution in pregnant and breastfeeding women, as its safety in these populations has not been fully established.  

Comorbidities: 

• Gastrointestinal disorders: Amino salicylic acid may worsen or trigger symptoms of inflammatory bowel disease, such as ulcerative colitis or Crohn’s disease. 
• Liver disease: The drug is metabolized by the liver and can cause liver damage or liver failure in patients with pre-existing liver disease. 
• Renal impairment: Amino salicylic acid is excreted by the kidneys, and its elimination may be prolonged in patients with renal impairment. 
• Blood disorders: Amino salicylic acid can cause blood disorders such as anemia, leukopenia, and thrombocytopenia. 
• Malnutrition: Malnourished patients may be at higher risk of adverse effects due to decreased absorption of the drug. 
• Alcoholism: Chronic alcohol use can increase the risk of liver damage or liver failure when combined with amino salicylic acid. 
• Hypersensitivity: Patients with a history of hypersensitivity to amino salicylic acid should use the drug with caution. 

Pregnancy / Lactation

Pregnancy consideration: US FDA pregnancy category: C 

Lactation: it is not known whether amino salicylic acid is excreted in breast milk  

Pregnancy category: 

• Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first or later trimester. 
• Category B: There is no evidence of risk to the fetus found in animal reproduction studies and there are not enough studies on pregnant women. 
• Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for an effect in humans, care must be taken for potential risks in pregnant women. 
• Category D: There is adequate data available with sufficient evidence of human fetal risk from various platforms, but despite potential risks may be used only in emergency cases for potential benefits. 
• Category X: Drugs listed in this category outweigh risks over benefits These category drugs should be prohibited for pregnant women. 
• Category N: There is no data available for the drug under this category. 

Pharmacology

Pharmacology: 

aminosalicylic acid (PAS) is an antibacterial agent used for the treatment of tuberculosis. The mechanism of action is aminosalicylic acid is unknown, but it is believed to work by inhibiting bacterial cell wall synthesis and disrupting the metabolism of mycolic acid, which is an essential component of the cell wall of Mycobacterium tuberculosis. 

PAS is well absorbed from the gastrointestinal tract and reaches peak plasma concentrations within 2-4 hours after oral administration. It is widely distributed in body tissues, including the lungs, liver, and kidneys. The drug gets extensively metabolized in the liver and excreted primarily in the urine, with a small amount eliminated in the feces. 

PAS is a bacteriostatic agent, and its activity is dependent on the concentration achieved at the site of infection. The drug is active against both intracellular and extracellular forms of Mycobacterium tuberculosis, but it is not effective against other microorganisms. PAS is often used in combination with other antituberculosis drugs to increase the efficacy of treatment and prevent the emergence of drug-resistant strains.  

Pharmacodynamics: 

aminosalicylic acid (ASA) is an antibiotic that belongs to the class of drugs known as antituberculosis agents. It works by inhibiting bacterial growth, specifically the synthesis of mycolic acid in the cell wall of the tuberculosis bacterium. 

ASA also has anti-inflammatory effects, which can be beneficial in the treatment of conditions such as ulcerative colitis. It works by inhibiting the production of inflammatory cytokines and reducing the migration of immune cells to the site of inflammation. 

The pharmacodynamics of ASA are dose-dependent, and the drug is typically administered in high doses for the treatment of tuberculosis and lower doses for the treatment of inflammatory bowel disease. The exact mechanism of action of ASA in the treatment of these conditions is not fully understood.  

Pharmacokinetics: 

Absorption 

aminosalicylic acid is rapidly and completely absorbed after oral administration. The absorption of PAS is enhanced in the presence of food. 

Distribution 

aminosalicylic acid is distributed throughout the body, with the high concentrations found in the liver and kidneys. 

Metabolism 

aminosalicylic acid undergoes acetylation in the liver, which results in the formation of its major metabolite, N-acetylaminosalicylic acid (Ac-PAS). 

Elimination and excretion 

aminosalicylic acid and its metabolites are primarily excreted in the urine, with a small amount excreted in the feces. The elimination half-life of PAS is approximately 2 hours. 

Adminstartion

Administration: 

aminosalicylic acid can be administered orally as a tablet, capsule, or powder. It is usually taken with food to minimize gastrointestinal side effects. The dosage of aminosalicylic acid depends on the condition being treated and the patient’s individual response to the medication.

aminosalicylic acid is often used in combination with other medications to treat tuberculosis, and it is important to take all the medications as prescribed and for the full duration of treatment. Failure to complete the full course of treatment may increase the risk of treatment failure, relapse, and the development of drug-resistant strains of tuberculosis. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: amino salicylic acid 

Pronounced: [ a-mee-noe-sal-i-SIL-ik-AS-id]  

Why do we use aminosalicylic acid? 

aminosalicylic acid (PAS) is an antibiotic used in the treatment of tuberculosis. It is given in combination with other medications to treat active tuberculosis or to prevent the development of active disease in people who are infected with tuberculosis but do not have symptoms. 

PAS is also used in the treatment of urinary tract infections by susceptible strains of bacteria. It may also be used in the treatment of other infections caused by susceptible organisms, although this use is less common.