Anti Malaria Tablet Information

Introduction

Malaria is widespread in many tropical and subtropical countries and is a serious and sometimes fatal disease. You cannot be vaccinated against malaria, but you can protect yourself in three ways.

Avoidance of Bites

Mosquitoes cause much inconvenience because of local reactions to the bites themselves and from the infections they transmit. Mosquitoes spread malaria, yellow fever, dengue and Japanese encephalitis.

Mosquitoes bite at any time of day but most bites occur in the evening.

Precautions to Take

Avoid mosquito bites, especially after sunset. If you are out at night wear long-sleeved clothing and long trousers.
Mosquitoes may bite through thin clothing, so spray an insecticide or repellent on them. Insect repellents should also be used on exposed skin.
Spraying insecticides in the room, burning pyrethroid coils and heating insecticide impregnated tablets all help to control mosquitoes.
If sleeping in an unscreened room, or out of doors, a mosquito net impregnated with insecticide is a sensible precaution. Portable, lightweight nets are available.
Garlic, Vitamin B and ultrasound devices do not prevent bites.

Taking Antimalarial Tablets

Start before travel as guided by your travel health advisor (with some tablets you should start three weeks before).
Take the tablets absolutely regularly, preferably with or after a meal.
It is extremely important to continue to take them for four weeks after you have returned, to cover the incubation period of the disease. Atovaquone/proguanil (Malarone®) requires only 7 days post-travel).

Drugs Most Commonly Used for Malaria Prevention

Travellers must always, through discussion with their doctor or pharmacist, make sure they use a drug which they can tolerate (only the more common side effects are given here) and one which is appropriate for their destination(s). No drug is 100% effective.

In Britain, chloroquine and proguanil can be purchased from local pharmacies or chemists. All other drugs require a doctor's prescription.

Further information on the commonly used drugs:

Chloroquine (licensed for prophylaxis in UK)

Patient Information Leaflet (PIL) for chloroquine

Preparations available: Avloclor® (Zeneca) and Nivaquine® (Rhône-Poulenc Rorer). Adult dose is 2 tablets (each containing 150mg chloroquine as base) taken once a week. Nivaquine is available in syrup form.
Consider a trial course before departure, if using this regime for the first time, to detect if you are likely to get side effects (e.g. for two weeks). Otherwise, when possible, chloroquine should be started one week before exposure (to ensure adequate blood levels), throughout exposure and for 4 weeks afterwards.
Nausea and sometimes diarrhoea can occur which may be reduced by taking tablets after food.
Headache, rashes, skin itch, disturbance of visual accommodation (often expressed as blurred distance vision which may take up to 4 weeks to reverse) or hair loss may warrant changing to alternative drugs.
Retinopathy (eye changes) which can be permanent is unlikely to occur until 100g have been consumed (i.e. over 5 years treatment at prophylactic doses).
Caution in liver and renal disease.
Can aggravate psoriasis and very occasionally causes a convulsion so it should not normally be used in those with epilepsy.
Chloroquine is very toxic in overdose - parents must take special care to store the tablets safely.
It is generally accepted, as a result of long usage, to be safe in pregnancy.

Proguanil (licensed for prophylaxis in UK)

Patient Information Leaflet (PIL) for proguanil

Preparations available: Paludrine® (Zeneca). Adult dose is 200mg daily.
Can normally be used continuously for a period of up to 5 years.
One or two doses should be taken before departure. It should be continued throughout exposure and for 4 weeks afterwards.
Anorexia, nausea, diarrhoea and aphthous (simple) mouth ulcers can occur.
Can delay the metabolism of the anticoagulant, warfarin, and result in bleeding. Those planning to take warfarin must discuss this with their doctor before starting any treatment.
Caution in renal impairment.
Considered to be safe in pregnancy, but folate supplement is advised.

Mefloquine® (licensed for prophylaxis in UK)

Patient Information Leaflet (PIL) for mefloquine

Preparations available: Lariam® (Roche). Adult dose is 250mg weekly.
One dose should be taken a week before departure and it should be continued throughout exposure and for 4 weeks afterwards however three (3) doses at weekly intervals prior to departure are advised if the drug has not been used before - this can often detect, in advance, those likely to get side effects so that an alternative can be prescribed.
Not licensed in Britain for use for more than 1 year (in countries where it is licensed for more than 1 year, additional side-effects are rare).
Nausea, diarrhoea, dizziness, abdominal pain, rashes and pruritus can occur.
Headache, dizziness, convulsions, sleep disturbances (insomnia, vivid dreams) and psychotic reactions such as depression have been reported. These reactions most commonly begin within 2-3 weeks of starting the drug and may be worse if alcohol is taken around the same time as the mefloquine.
Mefloquine is unsuitable for those who have a history of severe liver disease, depression, generalized anxiety disorder, psychosis, schizophrenia, suicide attempts, suicidal thoughts, self-endangering behaviour or any other psychiatric disorder, epilepsy or convulsions.
Caution, and avoid if alternatives are available, in severe renal or liver failure and those with heart rhythm defects. Also caution in those taking digoxin, beta or calcium channel blockers when arrhythmias and bradycardia can occur.
Although there is no evidence to suggest that mefloquine has caused harm to the foetus it should normally be avoided during the first trimester of pregnancy or if pregnancy is considered possible within 3 months of stopping prophylaxis.

Doxycycline (licensed for prophylaxis in UK)

Patient Information Leaflet (PIL) for doxycycline

Preparations available: Doxycycline (non-proprietary), Vibramycin® (Invicta). Adult dose is 100mg daily.
Can normally be used continuously for a period of at least 6 months - be guided by your doctor.
Consider a trial course before departure, if you are using this regime for the first time, to detect if you are likely to get side effects (e.g. for one week). Otherwise doxycycline need only be started just before exposure (e.g. 2 days), continued through exposure and for 4 weeks afterwards.
When other tetracyclines are being already used for acne this will provide protection against malaria so long as an adequate dose is taken (you can change to 100mg doxycycline per day if your doctor agrees).
Erythema (sunburn) due to sunlight sensitivity can occur. Use of sunscreens is especially important and if severe, alternative prophylaxis should be used.
Heartburn is common so the capsule should be taken with a full glass of water and preferably while standing upright.
Contraindicated in pregnancy (including one week after completing the course), breast feeding, in those with systemic lupus erythematosus, porphyria and children under 12 years because permanent tooth discolouration can occur.
01/03/11: New Guidance on Antibiotics and Combined Hormonal Contraceptives - the Royal College of Obstetricians and Gynaecologists have stated that women on non enzyme inducing antibiotics (doxycycline) are no longer required to take additional precautions during or after the course. The use of additional precautions does apply if vomiting or diarrhoea occurs as a result of antibiotic use or underlying illness.
Occasionally anorexia, nausea, diarrhoea, candida infection and sore tongue (glossitis) have been reported and rarely hepatitis, colitis and blood dyscrasias.

Atovaquone plus proguanil (licensed for prophylaxis in UK)

Patient Information Leaflet (PIL) for atovaquone/proguanil

Preparations available: Malarone®. Adult dose is one tablet daily - each tablet contains 250mg atovaquone plus 100mg proguanil. Child doses will be based on the weight of the child but will be once daily also.
DO NOT confuse with Maloprim® which is not now advised for prophylaxis since more effective alternatives are available.
Should be taken for 1 or 2 days before entering the malarious area, throughout exposure, and for 7 days after leaving the infected area. Licensed for trips of up to 28 days but there is no evidence of increased side-effects if used for longer.
Atovaquone/proguanil need only be commenced one or two days before exposure.
Abdominal pain, headache, anorexia, nausea, diarrhoea, coughing and aphthous (simple) mouth ulcers can occur.
Absorption may be reduced in diarrhoea and vomiting, and blood levels are significantly reduced with concomitant use of tetracyclines, metoclopramide and especially rifampicin or rifabutin.
The proguanil component can delay the metabolism of the anticoagulant, warfarin, and result in bleeding. Those planning to take warfarin must discuss this with their doctor before starting any treatment.
Caution in renal impairment.
Lack of experience in pregnancy and during breast feeding means that it should be avoided in these circumstances unless there is no suitable alternative.
The high cost makes popular for short trips.

Prompt Treatment

Following these guidelines faithfully might not guarantee complete protection. If you get a fever between one week after first exposure and up to one year after your return, you should seek medical attention and tell the doctor that you have been in a malarious area.