Travel to malarious areas should be avoided during pregnancy: if travel is unavoidable, effective prophylaxis must be used and the risks discussed. Pregnant women have an increased risk of developing severe malaria and a higher risk of fatality compared to non-pregnant women.

Bite avoidance measures are extremely important as pregnant women are particularly attractive to mosquitos (increased body temperature and release of carbon dioxide). Ideally, pregnant women should remain indoors between dusk and dawn. If they have to be outdoors at night they should adhere rigorously to bite precautions.

Chloroquine and proguanil are the preferred choices in pregnancy but they are inappropriate for many regions due to the presence of resistance. Folic acid 5mg should be given daily when proguanil is being used. Studies of mefloquine in pregnancy indicate that it can be considered in chloroquine-resistant areas. Doxycycline is contraindicated in pregnancy but in exceptional circumstances and where other options are unsuitable it can be given provided the full course is completed prior to 15 weeks gestation. Due to a lack of safety data in pregnancy, Malarone should be avoided in pregnancy unless there is no suitable alternative.


Antimalarials are excreted in breast milk however the amounts are too variable to provide reliable protection. Breast-fed babies will require their own prophylaxis based on the guidance provided in this resource.

Hepatic and renal impairment

Pharmacists should not recommend OTC antimalarial drugs to patients with hepatic or renal impairment; we are unable to make a clinical decision without access to accurate information on the degree of impairment. There may, however, be occasions where a healthcare professional is seeking advice on the prescribing of antimalarials in these patients.

Most antimalarial drugs are metabolised by the liver so there is a risk of drug accumulation in severe liver impairment. The choice of chemoprophylaxis should be made by the patient’s GP after discussion with the patient’s hospital specialist, who will be able to assess their degree of hepatic impairment.

Hepatic impairment

 Degree of hepatic impairment
Antimalarial drugSevereModerateMild
Malarone Ok Ok Ok
Proguanil Do not use Ok Ok
Chloroquine Do not use Do not use Ok
Mefloquine Do not use Ok Ok
Doxycycline Caution Caution Caution

Renal impairment

Antimalarial drugGuidance in renal impairment
Malarone Partially excreted by kidneys, dose reduction only required in severe impairment.
Proguanil Wholly excreted by kidneys, avoid if possible or reduce dose according to table below. Not to be used in patients receiving dialysis.
Chloroquine Not recommended for patients with a creatinine clearance of less than 30ml/minute. Not to be used in patients receiving dialysis.
Mefloquine Can be used in severe renal failure. No dose reduction required in dialysis patients.
Doxycycline Can be used in severe renal failure.

Proguanil dose reduction

Degree of renal impairmentSerum creatinine (μmol/litre)Creatinine clearance (ml/min/1.73m2)Proguanil dose for prophylaxis
None ≥ 60 200mg daily (standard)
Mild 150-300 20-59 100mg daily
Moderate 300-700 10-19 50mg alternate days
Severe >700 50mg once weekly