Related Experiment Video
Updated: Aug 15, 2025
Precision Implementation of Minimal Erythema Dose MED Testing to Assess Individual Variation in Human Inflammatory Response
Published on: October 3, 2019
Saline Vehicle Increases the Ability of Drug Patch Test in Cutaneous Adverse Drug Reactions
Supitchaya Thaiwat1, Sirikarn Prompongsa2
1Division of Dermatology, Department of Internal Medicine, Phramongkutklao Hospital, Bangkok, Thailand.
Background:
Drug patch test to identify cutaneous adverse drug reactions (CADRs) has been widely reported. Appropriate vehicles can improve the ability of drug delivery and significantly increase positive reaction of drug patch tests.
Objective:
The aim of this study was to evaluate the efficacy of drug patch tests using 0.9% saline vehicle in comparison with other traditional vehicles in CADRs.
Method:
All patients were patch tested with suspected drugs using 10-30% concentration of the commercialized form of drugs diluted in 0.9% saline, petrolatum, and water.
Result:
Of 100 patients with CADRs, 54 of those had at least one positive drug patch test. In terms of vehicles used, 43 patients had positive drug patch test with saline as compared to 35 with water (p = 0.485) and 25 with petrolatum (p = 0.007). Among CADRs subgroup, saline rendered significantly higher positive rate when compared with petrolatum in drug rash with eosinophilia and systemic symptom (DRESS) (70% vs. 20%, p = 0.025), maculopapular rash (MP) (52.4% vs. 31%, p = 0.046), and lichenoid drug eruption (46.7% vs. 0.0%, p = 0.002). 12/54 (22.2%) of CADRs patients had positive reaction with saline alone. Among these patients, 4/12 (33.3%) were lichenoid drug reaction, 3/12 (25%) were DRESS, and 2/12 (16.7%) were MP rash. Allopurinol was the drug giving positive patch test only with saline.
Conclusion:
Appropriate vehicles are essential to obtain the positive drug patch test. Using saline as a vehicle can increase the positive reaction of drug patch test, particularly in lichenoid drug eruption. We recommend the use of saline as another traditional vehicle in drug patch test.
Related Concept Videos
01:15Non-Oral Extravascular Drug Absorption Routes
Lipophilic drugs that are stable at salivary pH (6) and exhibit minimal binding to the oral mucosa are absorbed more...
01:22Drug Delivery: Miscellaneous Routes
Oral inhalation and nasal sprays swiftly transfer drugs across the respiratory epithelium's mucosal layer. Inhaled glucocorticoids and bronchodilators directly target lung conditions such as asthma, while fluticasone nasal spray mitigates allergic rhinitis.
Transdermal patches transport drugs...
01:10Drug Excretion: Miscellaneous Routes
01:09Methods for Studying Drug Absorption: In situ
The Doluisio method involves perfusing a prepared segment of a rat's small intestine with a solution of radiolabeled drug and a non-absorbable marker. This helps to differentiate between absorbed and non-absorbed drug concentrations. The intestinal segment is connected at both ends using tubing and syringes,...
01:19Pharmacovigilance
This process, termed pharmacovigilance, aims to detect, evaluate, and minimize harmful effects related to medication use. The data collection for pharmacovigilance depends on spontaneous reporting systems, where healthcare professionals or patients voluntarily report suspected ADRs.
In some cases, there...
01:25Routes of Drug Administration: Parenteral
The intravenous route (IV) of drug administration can be further categorized into two types. The bolus injection administers the entire dose rapidly, while an intravenous infusion slowly delivers smaller doses steadily.
The IV route is often...