Patients with hepatic impairment

• Doxycycline should be administered with caution to patients with hepatic impairment or those receiving potentially hepatotoxic drugs.

Serious skin reactions

• Serious skin reactions, such as exfoliative dermatitis, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug reaction with eosinophilia and systemic symptoms (DRESS) have been reported in patients receiving doxycycline. If serious skin reactions occur, you should discontinue doxycycline immediately .

Oesophagitis

• Instances of oesophagitis and oesophageal ulcerations have been reported in patients receiving capsule and tablet forms of drugs in the tetracycline class, including doxycycline. Most of these patients took medications immediately before going to bed or with inadequate amounts of fluid .

Missed doses

• A missed dose of doxycycline should be taken as soon as possible. If it is almost time for the next dose, the missed dose should be skipped and you should go back to the regular dosing schedule. Do not take 2 doses at once.

Antacids

• The absorption of doxycycline may be impaired by concurrently administered antacids containing aluminium, calcium, magnesium, or bismuth-containing products, iron, multivitamins with minerals or iron, urinary alkalinizers (e.g., sodium bicarbonate). Dosages should be separated by the maximum possible interval . 

• Photosensitivity manifested by an exaggerated sunburn reaction has been observed in some individuals taking tetracyclines, including doxycycline. This reaction can occur If you are exposed to direct sunlight or ultraviolet light whilst taking this drug and treatment should be discontinued at the first evidence of skin erythema. Photoonycholysis has also been reported in patients receiving doxycycline. 

Oral live typhoid vaccines

• Should preferably not be started within 3 days after the last dose of oral typhoid vaccine as doxycycline possibly reduces the efficacy of oral typhoid vaccine if given simultaneously .

Effects on ability to drive and use machines

• Visual disturbances such as blurring of vision may occur during treatment with doxycycline and if you are affected you must refrain from driving or operating machinery .

Planning a pregnancy

• Women of childbearing potential travelling to malarious areas in which multiple resistant P. falciparum is found and who are receiving doxycycline for the treatment and prophylaxis of malaria should take reliable contraceptive precautions for the entire duration of therapy and for one week after the last dose of doxycycline.

Pregnancy 

• If you are  Pregnant it is advisable to avoid travel to malaria areas.

• In the event that travel is unavoidable when pregnant you should be aware of the risks which malaria presentsto you, including an increased risk of developing severe malaria and a higher risk of fatality compared to non-pregnant women.

Benign intracranial hypertension

• Benign intracranial hypertension (pseudotumor cerebri) has been associated with the use of tetracyclines including doxycycline. Benign intracranial hypertension (pseudotumor cerebri) is usually transient, however cases of permanent visual loss secondary to benign intracranial hypertension (pseudotumor cerebri) have been reported with tetracyclines including doxycycline. If visual disturbances occur during treatment, you should go to a GP or A&E for ophthalmologic evaluation .

Microbial overgrowth

• The use of antibiotics may occasionally result in over-growth of non-susceptible organisms including Candida.

• If a resistant organism appears, the antibiotic should be discontinued and you should seek medical help.

• Pseudomembranous colitis has been reported with nearly all antibacterial agents, including doxycycline, and has ranged in severity from mild to life-threatening.If you develop  severe diarrhoea after taking doxycycline you should seek medical attention.

Clostridium difficile 

• Clostridium difficile Associated diarrhoea (CDAD) has been reported with use of doxycycline and can range in severity from mild diarrhoea to fatal colitis.

• CDAD must be considered if you present with diarrhoea following using this antibiotic. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.

Alcohol • Alcohol may decrease the half-life of doxycycline. Our advise is  to reduce alcohol intake during treatment.

Dose

• Prophylaxis for both adults and children should be initiated 24 or 48 hours prior to entering a malaria-endemic area, continued during the period of exposure and for 28 days after leaving the area .

• One 100mg doxycycline capsule  daily, orally in adults and children over the age of 12 years(1) .

• The capsules can be taken with food and must be swallowed whole with a full glass of water (240 mL) to help reduce the risk of throat or oesophagus irritation .

• Do not break, crush, or chew doxycycline capsules before swallowing.

• Do not lie down for 60 minutes after taking doxycycline capsules

• If gastric irritation occurs, it is recommended that they can be given with food or milk

•Please be aware that stopping a course of tablets early, even when you are no longer in a malaria area, can lead to you developing malaria infection if the parasites are already in your body.

 Doxycycline patient information leaflet

• Medications that would contraindicate the supply of doxycycline include, but not limited to, are warfarin, tretinoin, isotretinoin, alitretinoin, acitretin, acenocoumarol, phenindione, lithium, ciclosporin, carbamazepine, phenytoin, etc.

• Please state in our clinical questionnaire all medicines you are taking so our pharmacists can check for interactions or conditions which may exclude you from taking doxycycline.

• Caution is advised in administering tetracyclines with methoxyflurane

• It is advisable to avoid taking doxycycline in conjunction with penicillin

Malaria prevention

•It is a good idea before you travel to make yourself  aware of the current guidelines on malaria prevention and how to recognise signs and symptoms of malaria infection. A useful tool is the widely recognised ABCD approach to malaria prophylaxis: ̵ Awareness of risk ̵ Bite prevention ̵ Chemoprophylaxis ̵ Diagnose malaria promptly and treat without delay.

More information at Fit For Travel

• The Advisory Committee on Malaria Prevention (ACMP) recommends the following repellents: ̵ 50% DEET based insect repellent as first choice̵  20% Picaridin based insect repellent ̵ Eucalyptus citriodora oil ̵ 3-ethylaminoproprionate containing repellent

• Whilst no regime can provide total protection from becoming infected, taking sensible precautions will reduce risks. • If any illness occurs within 1 year and especially within 3 months of return from travelling to a risk area  then it might be malaria even if all recommended precautions against malaria were taken. You should go immediately to a doctor and specifically mention your exposure to malaria. Symptoms of malaria vary but typically include: fever, headache, fatigue, and muscle aches. Cough and diarrhoea may also occur.

Malaria prevention guidelines for travellers from the UK

• Common side effects include (≥1/100 to <1/10): Hypersensitivity (including anaphylactic shock, anaphylactic reaction, anaphylactoid reaction, exacerbation of systemic lupus erythematosus, serum sickness), headache, hypotension, nausea, vomiting, photosensitivity reaction, rash including maculopapular and erythematous rashes, Henoch- Schonlein purpura, urticaria, pericarditis, tachycardia, dyspnoea and peripheral oedema (1) . • Uncommon side effects include (≥1/1,000 to <1/100): Vaginal infection and dyspepsi .

• Rare side effects include (≥1/10,000 to <1/1,000): Candida Infection, pseudomembranous colitis, clostridium difficile colitis, haemolytic anaemia, neutropenia, thrombocytopenia, eosinophilia, Jarisch- Herxheimer reaction, porphyria, brown-black microscopic discolouration of thyroid glands, decreased appetite, benign intracranial hypertension, anxiety, tinnitus, flushing, pancreatitis, oesophageal ulcer, oesophagitis, enterocolitis, inflammatory lesions (with monilial overgrowth) in the anogenital region, dysphagia, abdominal pain, diarrhoea, glossitis, stomatitis, hepatic failure, hepatitis, hepatotoxicity, jaundice, hepatic function abnormal, Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), angioedema, toxic epidermal necrolysis, Stevens- Johnson syndrome, erythema multiforme, dermatitis exfoliative, photoonycholysis, skin hyperpigmentation, arthralgia and myalgia.