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Information for participants taking part in CERM

Drug interactions for doxycycline

If you are taking part in the trial and have been randomised (you are currently taking capsules), please avoid the medications listed below. These may cause side effects or be less effective when taken with doxycycline.

Please contact your hospital trial team if you are unsure about any medication.

  • Avoid methoxyflurane while you are taking the capsules
  • Warfarin
  • Penicillin
  • Antacids containing aluminium, calcium, magnesium or other drugs containing these cations; oral zinc, iron salts or bismuth preparations
  • Barbiturates, carbamazepine, primidone, phenytoin
  • Methoxyflurane (used as inhalation anaesthesia in emergency departments or prior to surgery)
  • Ciclosporin
  • Rifampicin
  • Ergotamine
  • Methysergide
  • Methotrexate
  • Kaolin
  • Sucralfate
  • Quinapril
  • Oral contraceptives
  • Retinoids (vitamin A or retinoids. Retinol, retinal, tretinoin (retinoic acid), isotretinoin, alitretinoin, etretinate, acitretin, adapalene, bexarotene, and tazarotene)
  • Oral typhoid vaccines
  • Fluorescence test
  • Drugs with the potential to cause hepatotoxicity

This is not an exhaustive list of drug interactions. Please refer to other references as necessary, including the Summary of Product Characteristics for doxycycline (this can be accessed hereLink opens in a new window).

Data privacy

University Hospital Coventry and Warwickshire (UHCW) is the sponsor for this trial in the United Kingdom. The trial will be managed by Warwick Clinical Trials Unit at the University of Warwick (UoW). UHCW and the UoW will use information you provide and information from your hospital records and your GP records to carry out this trial, and will act as joint data controllers for the trial. This means that, together, they are responsible for looking after your information and using it properly.

To find out more about how your information is handled, you can visit the privacy notices of the data controllers: opens in a new window opens in a new window



Warwick Clinical Trials Unit
Warwick Medical School
University of Warwick
Gibbet Hill Road