How Long Will Amoxicillin Remain In The System?

Posted on Wed, 30 Nov 2016

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Wed, 30 Nov 2016 Answered on

Fri, 16 Dec 2016 Last reviewed on

Question : How long will amoxicillin stay in your system? How many days since your last pill of amoxicillin Do you have to wait to make sure it won't interfere with syphilis blood test

Answered by Dr. Dr. Kakkar (3 hours later)

Brief Answer:
TPHA is not affected by antibiotic course unlike VDRL test

Detailed Answer:
Hello. Thank you for writing to us

I am dr.kakkar (dermatologist and venereologist). I have gone through your query and I have noted your concern.

A full course of oral penicillin taken anytime after syphilis infection can influence VDRL test which is a non specific test for syphilis. The antibiotic might delay seroconversion or the VDRL titres might fall after antibiotic treatment. Therefore it would not be reliable to have a wash off period after oral antibiotics for a VDRL test. Rather it would be better to go for a specific test like TPHA if one expects such a scenario. A specific test for syphilis e.g TPHA test stays positive throughout life irrespective of treatment.

Regards

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar