NCT00439166

Who might be able to join this trial:

• You can be either male or female
• You must be 50 years old or older
• You have been diagnosed with probable Alzheimer's disease (based on a specific set of medical guidelines called NINCDS-ADRDA criteria — confirm with trial site)
• You scored between 14 and 26 on a standard memory and thinking test called the Mini-Mental State Examination
• You have a caregiver who is willing to help manage your medications, report on how you are doing day-to-day, and bring you to appointments
• You have enough vision, hearing, and language ability to complete standard tests in English
• You (or your legal representative) are willing to give consent to take part
• You are generally in stable enough health that you could reasonably complete a one-year trial

Who may not be able to join:

• You have another brain or nerve condition such as Lewy body disease or Parkinson's disease
• Your memory or thinking problems are caused by something other than Alzheimer's, such as a head injury, lack of oxygen to the brain, vitamin B12 deficiency, infections like HIV/AIDS or meningitis, a brain tumour, or certain hormonal conditions
• You have significant disease affecting the blood vessels in your brain, or have had multiple small strokes affecting your thinking
• You have a growth or tumour inside your skull
• You have other serious health conditions such as epilepsy, major mental health conditions, significant depression (based on a specific scale score), or serious liver, kidney, lung, or hormonal problems
• You have significant heart disease, such as uncontrolled chest pain or uncontrolled high blood pressure
• You are taking any medication for Alzheimer's disease other than donepezil, galantamine, rivastigmine, or memantine
• You are already taking part in another clinical trial involving an experimental drug
• You have taken antibiotics for more than one month during the last six months
• You have a known allergy to doxycycline or rifampicin (the study medications)

Important: Always verify eligibility with the trial site directly before applying.