Doxycycline

What is Doxycycline?

Doxycycline is a broad-spectrum antibiotic used to treat a range of bacterial infections. It is commonly used as an antimalarial when travelling abroad to areas where malaria is known to be prevalent.

How does Doxycycline work?

Doxycycline is a tetracycline antibiotic, but it is often used for malaria prevention. Malaria is not a bacterial infection, but a parasitic one. Doxycycline works by preventing the parasites from invading the red blood cells giving the immune system more time to fight off the infection before you notice any symptoms. Doxycycline does not prevent malarial infection, but it does prevent the development of the disease if you are infected with the malaria parasites. 

How effective is Doxycycline?

Doxycycline is widely used because it is an effective treatment for a range of bacterial infections. However, overuse has lead some strains of bacteria to develop resistance to Doxycycline. Your doctor may choose to take a tissue sample from the infected area to ensure the bacteria causing the infection are susceptible to Doxycycline. If you are planning to use this medication as an antimalarial, check online or with a doctor if Doxycycline provides adequate protection from malaria in the area/s you are travelling to.

Active ingredients

The active ingredient in Doxycycline is doxycycline hyclate, an antibiotic used to treat a range of infections.

Inactive ingredients

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

Please Note: Inactive ingredients can vary between different brands of generic doxycycline.

How to take Doxycycline for malaria prevention

When taking Doxycycline for malaria prevention, you should start the course of medication 2 days before arriving in the malaria zone. The recommended dose is 1 capsule per day at around the same time each day. You should continue to take 1 capsule per day for 4 weeks after leaving a malaria zone.   

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.

When to start taking Doxycycline

You should start taking Doxycycline 2 days before travelling to a malaria zone.

When to stop taking Doxycycline

You should continue to take the recommended dose of Doxycycline for 4 weeks after leaving a malaria zone.  

What if I forget to take a dose?

If you're taking Doxycycline for malaria prevention, you should try to take it at the same time every day. If you do forget to take Doxycycline at the right time, you should take it as soon as possible and make sure you take the following dose at the correct time. If you miss a dose completely, you should not take a double dose, instead you should contact a medical professional for advice and take additional precautions against malaria i.e. staying inside more - especially at night, using mosquito nets etc. 

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.

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.  

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.

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.  

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.

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

Is photosensitivity a side effect of Doxycycline?

Doxycycline can make you more sensitive to sunlight and UV. You should alert your doctor if you expect to be exposed to high levels of UV, for example when using a sunbed while taking this medication. Take care to wear suncream in the sun, as well as sunglasses and long-sleeved clothing where possible.

Will Doxycycline affect my fertility?

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

Will Doxycycline affect my contraception?

Doxycycline can reduce the effectiveness of some oral contraceptives. It is recommended to use an alternative form of contraception, such as condoms, while using this medication.

What is malaria?

Malaria is a serious disease, spread by malaria-carrying mosquitos, which can be fatal in some cases depending on how quickly and effectively it is treated. Within approximately 2-4 weeks of becoming infected with the disease, symptoms such as fever, headache, muscle pain, nausea and vomiting begin to emerge. Doxycycline can be used to treat malaria after infection has occurred.

What are the uses of Doxycycline?

Like other tetracyclines, Doxycycline can be used to treat a broad range of bacterial infections, including acne and rosacea, chest infections, skin infections and STIs, as well as being used by travellers for malaria prevention.

Do I need to buy Doxycycline before I travel?

When using Doxycycline as an antimalarial, you will need to start the course before travelling to your destination and for some time after your return. You therefore need to purchase Doxycycline in advance of travelling to a malaria zone.

Is Doxycycline suitable for me if I’m going to a hot country?

One of the possible side effects of Doxycycline is increased sensitivity to sunlight. However, since Doxycycline is an effective and cheaper treatment for malaria prevention, it can still be used in hot countries as long as you take the appropriate precautions. Make sure to wear suncream with a high SPF, wear sunglasses and cover up as much as possible.

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. However, 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