Doxycycline

What is doxycycline used to treat?

Doxycycline is a broad-spectrum antibiotic. It is used to treat infections caused by bacteria and certain parasites. Doxycycline works by inhibiting protein synthesis in bacteria, effectively stopping their growth[1][4].  

It may be prescribed to treat conditions like: 

• Sexually transmitted infections (e.g., chlamydia, syphilis) 

• Skin infections (e.g., acne, rosacea) 

• Respiratory exacerbations and infections (e.g., pneumonia) 

• Gum disease 

• Infections caused by mites, ticks, or lice 

• Malaria prevention[2][4] 

How do you take doxycycline?

Doxycycline is available in various forms, including tablets, dispersible tablets, capsules, modified-release capsules and liquid suspensions. It should be taken with a full glass of water but can be taken can be taken with food or milk if it irritates the stomach.  

It’s important to take doxycycline while you’re in an upright position, whether sitting, standing or walking. You should also avoid lying down for at least 30 minutes after taking it to prevent irritation of the esophagus[1][2][6]. 

Who can take doxycycline?

Doxycycline is usually prescribed for adults and children over 12 years old[5].  

It may not be suitable for: 

• People who have had an allergic reaction to doxycycline or any other tetracyclines or excipients 

• Pregnant or breastfeeding women [3] 

• People with kidney or liver problems 

• People with an inflamed food pipe (oesophagitis) 

• People with lupus or myasthenia gravis[1][2] 

Please tell your doctor or pharmacist about any conditions you may have before starting doxycycline, and always follow the instructions in the Patient Information Leaflet[9].

What is the typical dosage of doxycycline?

The dosage will depend on why you’re taking doxycycline. The usual dose is 100mg to 200mg, taken once or twice a day[6]. 

If you’re taking doxycycline for conditions like rosacea or gum infections, you may take a lower dose, like 40mg once daily. 

If you’re taking it for malaria, the dosage will be 100mg once a day in the morning. 

You should always carry on taking your prescribed course of doxycycline treatment until it’s completed, even if you feel better, otherwise you run the risk of the infection returning. 

What do you do if you forget to take doxycycline?

If you miss a dose, take it as soon as you remember. If it's almost time for your next dose, skip the missed dose and continue with your regular schedule. Never double up on doses[1][2]. 

What to do if you take too much doxycycline?

Taking one extra dose of doxycycline shouldn’t harm you, but if you’re concerned or have taken more than one extra dose, you should speak to a pharmacist or doctor. 

What are the side effects of doxycycline?

The most common side effects of doxycycline will occur in around 1 in 10 people. These include[7]: 

• Nausea and vomiting 

• Mild diarrhoea 

• Skin rash, itching, or sensitivity to sunlight 

• Headaches 

Serious side effects can include: 

• Unexplained bruising or bleeding (sore throat, high temperature, and general feelings of tiredness or illness can be signs of blood problems too) 

• Diarrhoea containing blood or mucus, or severe diarrhoea that lasts longer than 4 days  

• Ear ringing or buzzing 

• Pale poo and/or dark pee, with yellowing of skin or eyes, as signs of liver problems 

• Joint or muscle pain 

• Headaches, vomiting, vision problems as signs of brain hypertension 

• Fingernail coming away from its base 

• Sore, swollen mouth, lips, or tongue 

• Severe stomach pain, with or without diarrhoea 

• Difficulty or pain when you swallow, a sore throat, acid reflux, chest pain, or a reduced appetite 

In very rare cases, doxycycline can cause a serious allergic reaction, known as anaphylaxis. 

If you experience any of these side effects, stop taking doxycycline and consult your GP or call 111. For more serious side effects, call 999 immediately.

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[9].

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice.

Medicines you can and can't take with doxycycline

You should speak to your doctor about interactions before taking doxycycline with[8]: 

• Antacids containing aluminium, calcium, or magnesium and medicines containing iron or zinc, 2 hours before or after you take this medicine 

• Stomach ulcer medicines, containing bismuth (i.e., Pepto-Bismol) 

• Immune system controlling drugs like ciclosporin  

• Other antibiotics, like rifampicin 

• Acne medicines containing vitamin A 

• Blood clot medicines like warfarin 

• Epilepsy medicines, like phenytoin or carbamazepine

Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[9]. 

Frequently asked questions about doxycycline

Do you need to avoid strong sunlight whilst taking doxycycline? 

Yes, you should avoid exposure to strong sunlight or UV light (e.g. on a sunbed) whilst taking this medicine as you skin will be more sensitive to sunburn.  

Can doxycycline be taken with food?  

Yes, it can be taken with food. This is likely to reduce the risk of stomach upset or throat irritation as a side effect[1]. 

How long does doxycycline take to work?  

Doxycycline typically starts working within a few days, but the duration of treatment can range from 7 to 14 days[1]. 

Can you drink alcohol with doxycycline? 

It is recommended that you avoid alcohol while taking doxycycline. It can increase the risk of side effects and exacerbate any you have already experienced (i.e., mild stomach upset). 

Does doxycycline make you tired? 

Doxycycline doesn’t cause fatigue. It’s more likely due to the infection or your immune system fighting the infection. You should regain your normal energy within a few days. 

Does doxycycline contain penicillin? 

No, it does not contain penicillin. It belongs to a class of drugs called tetracyclines, which are unrelated to penicillin.  

Can you take paracetamol with doxycycline? 

Yes, painkillers like paracetamol and ibuprofen are safe to take with doxycycline. 

For the official NHS guide to doxycycline, visit their website.