Protozoal Infection

Question 1

Mefloquine and Chloroquine are unsuitable for Malaria prophylaxis in

Answer 1

those with a history of epilepsy.

Question 2

Chloroquine

Answer 2

• Chloroquine is used for the prophylaxis of malaria in areas of the world where the risk of chloroquine-resistant falciparum malaria is still low. It is no longer recommended for the treatment of falciparum malaria due to widespread resistance… Do not use in epilepsy patients. Can be sold OTC
• But it is still recommended for the treatment of non-falciparum malaria.

Question 3

Mefloquine

Answer 3

• Mefloquine is used for the prophylaxis of malaria in areas of the world where there is a high-risk of chloroquine-resistant falciparum malaria. It is rarely used for the treatment of falciparum malaria due to widespread resistance.
• It is rarely used for the treatment of non-falciparum malaria because better tolerated alternatives exist.
  Cautions, further information: mefloquine is associated with serious neuropsychiatric reactions. Abnormal dreams, insomnia, anxiety and depression occur commonly. Adverse reactions may occur and persist for several months after discontinuation due to the long half-life of the drug.

Question 4

Proguanil

Answer 4

Proguanil is used (usually with chloroquine) for the prophylaxis of malaria.
• Proguanil used alone is not suitable for treatment of malaria however, Malarone (combination of atovaquone and proguanil) is licensed for treatment of acute falciparum malaria.
• Malarone is also used for prophylaxis of malaria in areas of the world where there is chloroquine or mefloquine resistance.
• Malarone is suitable for short trips to chloroquine resistant areas as it only needs to be taken for 7 days after leaving an endemic area.

Question 5

Quinine

Answer 5

Quinine is not suitable for the prophylaxis of malaria but can be used for the treatment of falciparum malaria, for malaria caused by unknown species and for mixed infections
Dose equivalence and conversion: when using Quinine for malaria… doses are valid for quinine hydrochloride, dihydrochloride and sulphate. They are not valid for quinine bisulphate which contains a smaller amount of quinine.

Question 6

Tetracyclines

Answer 6

Doxycycline can be used in adults and children over 12 for the prophylaxis of malaria in areas of widespread mefloquine or chloroquine resistance. It can also be used as an alternative to Malarone.

Question 7

Prophylaxis - Protection against bites

Answer 7

 Mosquito nets impregnated with permethrin provide the most effective protection against insects
 Diethyltoluamide (DEET) 20-50% (available as sprays) can be applied to the skin of adults and children over 2 months of age. It can also be used during pregnancy + breast-feeding.
 The duration of protection varies according to the conc. Of DEET (longest for 50%).
 When sunscreen is required, DEET should be applied after sunscreen. DEET reduces the Sun Protecting Factor of sunscreen so a sunscreen of SPF 30-50 should be used

Question 8

Long term treatment

Answer 8

Mefloquine is licensed for use up to 1 year
Doxycycline can be used for up to 2 years
Malarone can be used for up to 1 year

Question 9

Length of prophylaxis

Answer 9

Prophylaxis should generally be started 1 week before travel into an endemic area.
- Prophylaxis should be started 2-3 weeks before travel in the case of Mefloquine and 1-2 days before travel in the case of Malarone or Doxycycline
Prophylaxis should be continued for 4 weeks after leaving the endemic area
- Except for Malarone (atovaquone with proguanil) which should be stopped 1 week after leaving

Question 10

Return from malarial region

Answer 10

Any illness that occurs within 1 year and especially 3 months of return might be malaria even if precautions were taken. Travellers should be warned of this and told that if they develop any illness (particularly within 3 months) of their return… they should immediately see a doctor.

Question 11

Pregnancy

Answer 11

• Chloroquine and Proguanil can be given at the usual doses during pregnancy, but their effectiveness has declined particularly in Sub-Saharan Africa.
• If Proguanil is used… Folic acid should be given for atleast the 1st trimester.
• Mefloquine should not be used in pregnancy unless the benefit outweighs the risk.
• Doxycycline is contraindicated in pregnancy, but it can be used for prophylaxis if other drugs are unsuitable and if the entire course can be completed before 15 weeks’ gestation.
• Malarone should be avoided during pregnancy but it can be considered during 2nd and 3rd trimester if there is no suitable alternative (give with folic acid)

Question 12

Breast-feeding

Answer 12

Prophylaxis is required in breast-fed infants. Although antimalarials are present in breastmilk, the amounts are too variable to give reliable protection.

Question 13

Anticoagulants

Answer 13

• Travellers taking Warfarin should begin prophylaxis 2-3 weeks before departure.
• The INR should be stable before departure and measured before starting prophylaxis, 7 days after starting and after completing the course.

Question 14

Malaria Treatment

Answer 14

If the infective species is not known, or if the infection is mixed… initial treatment should be as for Falciparum Malaria with Quinine, Malarone or Riamet (artemether with Lumefantrine)

Question 15

Clindamycin, side effects further information:

Answer 15

• Antibiotic associated colitis: A common side effect of Clindamycin is diarrhoea which can lead to colitis. If diarrhoea occurs, the drug should be stopped, and medical attention sought.

Question 16

Falciparum malaria treatment

Answer 16

Quinine, Malarone or Riamet can be given by mouth if the patient can swallow and if there are no serious manifestations (e.g. impaired consciousness).

• If the patient is seriously ill or unable to take tablets, then Quinine can be given by I.V. infusion.
• Oral quinine is given by mouth for 5-7 days together with or followed by either Doxycycline or Clindamycin for 7 days.
• Alternatively, Malarone or Riamet may be given instead of Quinine. However, it is not necessary to give Doxycycline or Clindamycin after Malarone or Riamet treatment.

Question 17

Quinine can be given by I.V. infusion

Answer 17

The I.V. infusion is given until the patient can swallow tablets to complete the 7-day course together with or followed by doxycycline or clindamycin.

Question 18

Falciparum malaria treatment in Pregnancy

Answer 18

• The adult treatment doses for oral and I.V. Quinine can safely be given to pregnant women. Clindamycin should be given after Quinine (as Doxycycline is contraindicated in pregnancy)
• Malarone and Riamet are best avoided in pregnancy.

Question 19

Non-falciparum malaria treatment

Answer 19

• Chloroquine is the drug of choice for the treatment of non-falciparum malaria.
• For the treatment of chloroquine-resistant malaria, Malarone, Quinine or Riamet can be used.
• Primaquine is given after chloroquine to destroy parasites in the liver + thus prevent relapses.
• If the patient cannot take oral therapy… I.V. quinine can be given which is changed to oral chloroquine as soon as the patient’s condition improves.

Question 20

Non-falciparum malaria treatment in Pregnancy

Answer 20

The adult treatment doses of chloroquine can be given during pregnancy, however the radical cure with Primaquine should be postponed until pregnancy is over; instead chloroquine should be continued