Doxycycline Antibiotics

What is Doxycycline?

Doxycycline is an antibiotic used to treat a broad range of bacterial infections. It is commonly used to treat sexually transmitted infections (STIs) such as chlamydia, and is also used as an antimalarial when travelling. 

How effective is Doxycycline?

While Doxycycline is thought of as an effective treatment for many types of bacterial infection, its wide usage has meant that some strains of bacteria have developed resistance to it. Your doctor may chose to take a tissue sample from the infected area to ensure that the bacteria causing the infection are susceptible to Doxycycline. 

How does Doxycycline work?

Doxycycline is a type of antibiotic known as a tetracycline. It works by inhibiting the growth and reproduction of bacteria, preventing the spread of infection and allowing the body’s immune system to kill of the remaining bacteria. 

Active ingredients

The active ingredient in Doxycycline is doxycycline hyclate.

Inactive ingredients

The inactive ingredients in Doxycycline are sucrose, maize starch, crospovidone, basic butylated methacrylate copolymer (Eudragit E100) and purified talc.

How to take Doxycycline for Chlamydia

You should take Doxycycline as instructed by your doctor. The usual dose for treatment of an STI such as chlamydia is 100 mg per day for 7-10 days.

Each tablet should be swallowed whole with a glass of water around the same time every day. Try not to lie down for 30 minutes after taking this medication, in order not to disrupt its passage to the stomach.  

Doxycycline dosage

For adults and children over the age of 12, the recommended dose is 200 mg on the first day of treatment, then 100 mg each day for the duration of the course. The length of the course will depend on the type of infection you have, so follow the directions given to you by your doctor.

How long does Doxycycline take to work?

Doxycycline usually begins to work after a couple of days, when you may noticed marked improvements. However, a course of Doxycycline can range from 3 days to several weeks, and you should always continue taking this medication as directed by your doctor. 

Should you take Doxycycline with food?

Doxycycline can be taken with or without food. If you find that you feel nauseous, you may find it easier to take Doxycycline with or directly after a meal. However, avoid taking this medication directly with dairy products such as milk or yoghurt, as these can reduce its effectiveness.

What is I forget to take a dose?

Doxycycline should be taken at the same time/s each day. If you forget to take your dose at the correct time, take it as soon as you remember and then take your next dose at the normal time. Never take a double dose to make up for the missed one.

Do I need to finish the course, even if my symptoms clear up?

You should always finish a course of antibiotics, even if your symptoms clear up. The length of your course will depend on the type of infection you have, so always follow the instructions of the doctor who prescribed you the course of doxycycline. Failure to finish the course may allow some bacteria to remain in your system and develop resistance to Doxycycline.

Will Doxycycline affect my contraception?

Doxycycline may reduce the effectiveness of some oral contraceptives. Speak to your doctor for advice on whether you need to use alternative forms of contraception while taking Doxycycline.

Doxycycline and pregnancy

Speak to your doctor for advice if you are pregnant, planning to become pregnant, or breastfeeding, at this medication could harm the infant.

Doxycycline and alcohol

It is advised not to drink alcohol while taking Doxycycline, as this may reduce the effectiveness of your medication.

Contraindications

Do not take this medicine before alerting your doctor if:

• You have suffered an allergic reaction to Doxycycline or any other antibiotic in the past.
• You are allergic to any of the ingredients in Doxycycline.
• You are pregnant or intend to become pregnant.
• You are breastfeeding.

Consult your doctor before taking Doxycycline if:

• You are going to be exposed to strong sunlight or ultraviolet.
• Have liver problems.
• Have severe kidney problems.
• Have myasthenia gravis.
• Have porphyria.
• Have systemic lupus erythematosus.
• Have diarrhoea or usually experience diarrhoea when taking antibiotics.  

Will Doxycycline affect my fertility?

There is no evidence to suggest that Doxycycline has an effect on male or female fertility.

How to cope with Doxycycline side effects

Some common side effects of Doxycycline include headaches, nausea or vomiting and sensitivity to sunlight. Some measures you can take to manage these side effects include:

• Drink plenty of water and stay rested.
• Take painkillers such as paracetamol and ibuprofen to ease headaches.
• Take your dose of Doxycycline with or after a meal to reduce nausea, but do not take it directly with milk or other dairy products.
• If you are vomiting, try eating simple meals and stay well hydrated. Speak to your doctor if vomiting if preventing you from taking your medication altogether.
• Doxycycline can increase your skin’s sensitivity to sunlight. Make sure to wear plenty of sun cream when going out in the sun, and wear sunglasses and clothes that cover you up.

Drug Interactions

You should inform your doctor if you are taing, have recently taken, or are about to start taking and other medicines, including those purchased over the counter. In particular, tell your doctor if you are taking:

• Penicillin.
• Rifampicin.
• Anticoagulants.
• Quinapril.
• Kaolin.
• Sucralfate.
• Oral contraceptives.
• Barbiturates.
• Ergotamine or methysergide.
• Typhoid vaccine.
• Carbamazepine.
• Ciclosporin.
• Methoxyflurane.
• Antacids and other medicines containing aluminium, calcium, magnesium, iron, bismuth or zinc salts.
• Retinoids.  

Doxycycline Side Effects

Like all medications, Doxycycline can cause side effects in some patients. If you experience any of the following, stop taking your medicine and seek medical attention immediately:

Symptoms of an allergic reaction, including sudden wheezing and difficulty breathing, chest pain, swelling of the face, lips, tongue, throat, hands or feet, fever, rash, pericarditis (inflammation of the membrane surrounding the heart), worsening of autoimmune disease. Symptoms of DRESS (Drug Reaction with Eosinophilia and Systemic Symptoms), such as fever, swollen lymph nodes or skin rash.

If you experience any of the following infrequent side effects, seek advice from your doctor as soon as possible:

• Severe skin reactions involving irregular, circular patches, flushing, fever blisters, ulcers, reddening, peeling and swelling, which could indicate erythema multiforme, Stevens-Johnson syndrome or toxic epidermal necrolysis. 
• Sensitivity to sunlight.
• Increased pressure in the skull or severe headaches.
• Bulging fontanelles on infants.
• Swollen tongue.
• Severe and/or bloody diarrhoea.
• Low blood pressure.
• Aching joints or muscles.
• Unusual or rapid heart beat
• Fainting.
• Blood disorders, characterised by tiredness, weakness and easy bruising.
• Porphyria, characterised by sensitivity to sunlight, inflammation of the nerves and stomach pains.
• Discolouration of thyroid tissue.
• Changes in liver function tests.
• Hepatitis.
• Liver failure.
• Increased urea in the blood.
• Jaundice, characterised by yellowing of the skin or whites of the eyes.
• Pancreatitis.
• Loosening of the nail from the nail bed.
• Fever, chills, headache, muscle pain and skin rash, which could be symptomatic of the Jarisch-Herxheimer reaction.
• Black hairy tongue.
• Heartburn.
• Ringing in the ears.
• Anxiety.

Mild, infrequent side effects include:

• Inflammation of the gastrointestinal tract.
• Nausea, vomiting or diarrhoea.
• Loss of appetite.
• Soreness and itching of the genital or rectal area.
• Yeast infection of the genital or anal area.

If the above side effects are troubling you, consult your doctor for advice.  

What are the uses of Doxycycline?

Doxycycline is a broad-spectrum antibiotic and can be used to treat a number of bacterial infections. Common uses of Doxycycline include the treatment of acne and rosacea, chest infections, skin infections, STIs, and prevention of malaria in travellers.

Will Doxycycline stain my teeth?

You should avoid using doxycycline during periods of tooth development, such as during pregnancy or in children under the age of 8. This can lead to permanent discolouration of the teeth. In severe or life-threatening circumstances, your doctor may decided that the benefits outweigh the risks and prescribe Doxycycline in children under the age of 8.

Will Doxycycline give me thrush?

Doxycycline is a broad-spectrum antibiotic, meaning it suppresses some bacteria that resides naturally in the body. This can lead to an overgrowth of other bacteria, or of fungal and yeast infections. For this reason, using Doxycycline can lead to an outbreak of thrush in some patients. 

Is Doxycycline an antibiotic?

Doxycycline is a tetracycline antibiotic which is used to treat a broad range of bacterial infections.

Sources

• Patient Information Leaflet
• NHS > Doxycycline