Pregnancy
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.
Breastfeeding
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 drug | Severe | Moderate | Mild |
| 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 drug | Guidance 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 impairment | Serum 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 |