Doxycycline Side Effects

How Can You Manage Them During Treatment?

Whether you're thinking of starting Doxycycline treatment or you're already taking it, knowing what side effects you could experience is a good idea.

If you know how to recognise the side effects of Doxycycline and know how to respond to them, it can help you manage your treatment and get the most out of it.

What Are the Side effects of Doxycycline?

More common side effects – most people don’t experience side effects whilst taking Doxycycline. However, side effects do happen and these are the symptoms to watch out for:

  • Skin that burns more easily in the sun.
  • A sore mouth, indigestion, and difficulty swallowing. This might be a sign that your digestive tract is a little inflamed from the medicine.
  • Feeling sick (nausea), being sick (vomiting), or a loss of appetite.
  • Loose stools or diarrhoea.
  • A ringing or buzzing noise in the ear (tinnitus).
  • Soreness or itchiness around the anus or genitals.
  • A yeast infection around the anus or genitals.

Rarer side effects – some of these side effects, although very rare, are more serious. You should see a doctor as soon as possible if you experience these symptoms:

  • A red rash on your skin, which could look like blisters or burns.
  • A severe skin reaction when exposed to sunlight (for example, blistering and eye pain).
  • A severe headache or changes to your vision. This might be a sign that there is increased pressure around the brain and could lead to long-term complications.
  • Severe stomach cramps, fever, and bloody or watery diarrhoea. This is a condition called pseudomembranous colitis, where your digestive tract is badly inflamed from the medicine.
  • Feeling a rapid heartbeat (palpitations), feeling dizzy, or fainting.
  • Severe pain in your abdomen.

Allergic reaction – you can get an allergic reaction if you take Doxycycline. This can range from a mild to a life-threatening reaction.

Severity Symptoms Action Mild

  • A skin rash (hives) which may be itchy
  • If these symptoms are troublesome, you can take antihistamines or go to your local chemist to speak to a pharmacist Severe
  • Breathing problems, wheezing, or chest pain
  • Swelling of the lips and face
  • A rash that affects the whole body

These symptoms can be life-threatening. Go to your nearest Accident & Emergency department if possible or call 999

What to Do if You Think You’re Having Side Effects From Doxycycline

How to avoid side effects – take the medication as directed by your doctor and the information leaflet, including being careful to:

  • Avoid excess sun exposure by covering up your skin and using high-factor sun screen to prevent sunburn
  • Take each tablet with a glass of water and sit up for 30 minutes afterwards
  • Take Doxycycline with meals if you are suffering from any gastric upset

How to recognise side effects – most side effects from Doxycycline normally come on very quickly (that is, no more than a few hours after you’ve taken the medicine). If you experience any of the symptoms listed above soon after you take Doxycycline, you may be experiencing a side effect or an allergic reaction to the medicine.

What to do – if you think you are having side effects from Doxycycline, the quickest way to resolve this is to go to your local chemist to speak to the pharmacist on duty. They will be able to advise you on the most appropriate treatment. This might be:

  • Stopping your course of medication
  • Suggesting an alternative medication
  • Taking an antihistamine to ease symptoms of a mild allergic reaction
  • Advice to make an appointment with a doctor

Emergency action – if your symptoms are serious or extremely bothersome, you can make an appointment to see your doctor. If you think you are experiencing the symptoms of a severe allergic reaction listed above, you should go to your nearest Accident & Emergency department or call 999 immediately. Make sure that you are not on your own at any time and do not drive yourself.

Should I stop taking Doxycycline? – do not stop your course of treatment without the advice of a pharmacist or a doctor. The treatment could fail, and the bacteria causing the condition that you are being treated for may become resistant to Doxycycline.

Can You Carry on Treatment With Side Effects?

You can do if your side effects are mild – if you find that the side effects are not too bothersome, it may be worth completing your course of treatment. However, if you cannot tolerate the side effects from Doxycycline, you should speak to a doctor to see whether there are any alternative treatments that you can take.

If you throw up your capsule – if you experience vomiting as a side effect of Doxycycline, the full dose of medicine may not get into your system. You should speak to a doctor to see if there are any alternative treatments.

Do side effects stop treatment from working? – having side effects from Doxycycline does not mean that your treatment won’t work. Side effects can occur with any medicine that you take, including antibiotics such as Doxycycline.

Are Side Effects Different Depending on Why You’re Taking Doxycycline?

Not directly – it’s not what you’re using it for, but how strong your dosage – the higher the dose of Doxycycline, the more likely you are to experience side effects and the worse the symptoms of the side effects could be. Also, if you are taking Doxycycline for a prolonged length of time, you are at more risk of getting inflammation of the digestive tract. The side effects, however, are roughly the same no matter what dosage you are taking.

Does dosage change depending on what’s being treated? – yes. The dose of doxycycline you are given depends on what you’re being treated for. Some examples are given below.

Why you're taking Doxycycline Treatment Sexually transmitted infections (STIs), such as chlamydia 100mg twice a day (totalling 200mg per day) Preventing malaria; for example, if you are travelling to a country where malarial infections are common 100mg from a few days before you travel to four weeks after you leave Treating malaria if you’ve already got it 200mg a day

Are There Any Other Risks to Taking Doxycycline?

No long-term risks for adults – taking Doxycycline long-term is not associated with any more complications compared to taking a short course. Some studies found that healthy research volunteers gained weight whilst they have been taking Doxycycline.

For children – children under 12 years old should not take Doxycycline because of the effects that it can have on growing bones and teeth. Check with your doctor if your child has been prescribed with this medicine.

There are risks associated with drinking during treatment – you should not drink alcohol whilst you are taking Doxycycline as both of these can be harmful to the liver. Damage to the liver due to Doxycycline is very rare, but the likelihood of this is increased if you also drink alcohol.


  • Angelakis, E. et al (2014). Abnormal weight gain and gut microbiota modifications are side effects of long-term doxycycline and hydroxychloroquine treatment. Antimicrobial Agents and Chemotherapy, Jun; 58(6): 3342-3347.
  • British National Formulary. Doxycycline. NICE. [online] Available at: [accessed 16th April 2018].
  • British National Formulary. Doxycycline. NICE. [online] Available at: [accessed 16th April 2018].
  • Kent Pharmaceuticals Ltd. (2017). Doxycycline 100mg capsules. Electronic Medicines Compendium. [online] Available at: [accessed 16th April 2018].
  • Walker, C. et al (2005). Long‐term treatment with sub‐antimicrobial dose doxycycline has no antibacterial effect on intestinal flora. Journal of Clinical Periodontology, Oct; 32(11): 1163-1169.

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