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para-aminosalicylate; PAS; 4-aminosalicylate (Pamisyl, Paser)
Indications:
- adjunctive treatment of tuberculosis
- Crohn's disease, ulcerative colitis [3]
Contraindications: Warnings:
- avoid use in patients with:
a) hepatic or renal dysfunction
b) gastric bleeding disorders
c) glucose-6-phosphate dehydrogenase (G6PD) deficiency
Dosage:
1) adults: 12-15 g/day divided TID-QID
2) children: 240-360 mg/kg/day divdided TID-QID
3) take with food
4) avoid exposing drug to moisture, extreme heat or direct sunlight
Tabs: 500 mg, Granules
Pharmacokinetics:
1) oral dose readily absorbed
2) widely distributed to tissues
- CSF penetration only through inflammed meninges
3) protein binding 50-70%
4) peak concentration within 1-4 hours
5) 1/2life 1 hour
Adverse effects:
1) not common (1-10%)
- nausea/vomiting, diarrhea, abdominal pain
2) uncommon (< 1%)
- fever, skin eruptions, leukopenia, agranulocytosis, thrombocytopenia, hemolytic anemia, goiter with or without myxedema, jaundice, hepatitis, vasculitis
2) other
- hypersensitivity [4]
- hypothyroidism, especially when used in combination with ethionamide [4]
Drug interactions:
1) PAS interferes with rifampin absorption
2) PAS displaces phenytoin from albumin, thus raising free phenytoin levels
3) probenecid can increase PAS levels
Test interactions:
- false positive reactions with copper sulfate urine glucose test
Interactions
drug interactions
drug adverse effects of NSAIDs
monitor with non steroidal anti-inflammatory agents (NSIADs)
General
aminosalicylate; aminosalicylic acid
anti-tuberculous agent
Properties
INHIBITS: cyclooxygenase
MISC-INFO: elimination route INTESTINE
LIVER
KIDNEY
1/2life 1 HOUR
protein-binding 50-70%
Database Correlations
PUBCHEM cid=4649
References
- Kaiser Permanente Northern California Regional Drug
Formulary, 1998
- RxList
http://www.rxlist.com/paser-drug.htm
- Deprecated Reference
- Medical Knowledge Self Assessment Program (MKSAP) 17, 18.
American College of Physicians, Philadelphia 2015, 2018