Antimalarial Drugs During pPregnancy

QUESTION

What is the safest antimalarial drug to be used by a pregnant woman in her second trimester?

ANSWER

With regards to treating malaria, intravenous artesunate (or quinine, if artesunate is not available) should be used for the treatment of severe/complicated Plasmodium falciparum malaria. Signs of severe and/or complicated malaria include impaired consciousness, organ failure, abnormal bleeding, hypoglycemia, severe anemia and/or inability to ingest medication orally. Treatment for uncomplicated malaria (where the above signs are absent) in pregnant women is usually chloroquine for P. vivax, P. ovale, P. knowlesi and P. malariae, as well as for P. falciparum if there are no reports of this parasite being resistant to chloroquine in the area. In places where P. falciparum is resistant to chloroquine, quinine and clindamycin should be used to treat this parasite in pregnant women.

As for preventative anti-malarials (chemoprophylaxis), if a pregnant woman is travelling to an area where only P. vivax, P. ovale, P. knowlesi, P. malariae or chloroquine-sensitive P. falciparum is transmitted, then she should take chloroquine to prevent malaria. In areas where P. falciparum is resistant to chloroquine, mefloquine is also suitable during pregnancy. Note that in some areas of south-east Asia, there are areas where P. falciparum is resistant to mefloquine, which may prevent its suitability as a prophylactic in this region. Preventing malaria during pregnancy is crucial, since the mother, particularly if it is her first baby, is especially vulnerable to the parasite. Moreover, malaria can have a negative impact on the fetus.

Treatment of recurrent Malaria

QUESTION

If one takes the first dose of Coartem and tests indicate presence of malaria parasites,is it advisable to take a second round of coartem, or to start on quinine? Is quinine usually administered on its own or in conjunction with another drug? At what point is malaria considered complicated?

ANSWER

Usually, if a first round of treatment is unsuccessful, a doctor will prescribe a different type of oral medication for another attempt, such as atovaquone-proguanil or doxycycline in combination with another anti-malarial.

Quinine, when administered orally, can be given alone but is more commonly given with another anti-malarial compound such as doxycycline, tetracycline or clindamycin.

In cases of complicated malaria, it is administered intravenously. There are a number of symptoms which, in combination with a history of high fever, define complicated/severe malaria, among which are:

  • Prostration (inability to sit), altered consciousness lethargy or coma
  • Breathing difficulties
  • Severe anaemia
  • Generalized convulsions/fits
  • Inability to drink/vomiting
  • Dark and/or limited production of urine

In addition, intravenous quinine may be given to patients who are unable to take oral medication for whatever reason.

Malaria Treatments

QUESTION

What are the of different types of antimalaria drugs?

ANSWER

Most drugs used in treatment are active against the parasite forms in the blood (the form that causes disease) and include:

  • chloroquine
  • atovaquone-proguanil (Malarone®)
  • artemether-lumefantrine (Coartem®)
  • artesunate-pyronaridine (Pyramax®)
  • dihydroartemisinin-piperaquine (Duo-Cotecxin®)
  • mefloquine (Lariam®)
  • quinine (given intravenously, this is recommended first-line treatment for severe, complicated malaria)
  • quinidine
  • doxycycline (used in combination with quinine)
  • clindamycin (used in combination with quinine)

All of the treatments above which combine an artemisinin-derivative (such as artemether, artesunate or dihydroartemisinin) in combination with another anti-malarial are called the artemisinin-based combination therapies (ACTs) and are collectively recommended by the World Health Organisation as the first line medication against uncomplicated malaria.

In addition, primaquine is active against the dormant parasite liver forms (hypnozoites) and prevents relapses. Primaquine should not be taken by pregnant women or by people who are deficient in G6PD (glucose-6-phosphate dehydrogenase). Patients should not take primaquine until a screening test has excluded G6PD deficiency.

Drugs to Treat Pregnant Woman with Malaria

QUESTION:

What are the drugs for a pregnant woman who has malaria for the first to third trimester?

ANSWER:

The treatment of malaria in pregnant women has become more challenging in recent years, as many types of malaria are developing resistance to the standard arsenal of drugs. In locations where the dominant form of malaria is still chloroquine-sensitive, chloroquine can be used safely throughout pregnancy.

However, given the high levels of chloroquine-resistance, other drug regimens may be required. Currently, first-line treatment options for uncomplicated malaria caused by Plasmodium falciparum (many strains of which are resistant to chloroquine), is quinine plus clindamycin (doxycycline is contraindicated in pregnant women). In the second and third trimesters, artesunate plus clindamycin can be administered, or the artemisinin-based combination therapy (ACT) commonly used in that region, although some of these combinations, particularly those containing artemether, have limited safety testing in pregnant women. In general, the paucity of controlled, randomized trials has posed a problem to creating safe and effective recommendations for the treatment of malaria in pregnant women.

Malaria Treatment

Malaria can be a severe, potentially fatal disease (especially when caused by Plasmodium falciparum) and treatment should be initiated as soon as possible.

Patients who have severe P. falciparum malaria or who cannot take oral medications should be given the treatment by continuous intravenous infusion.

Most drugs used in treatment are active against the parasite forms in the blood (the form that causes disease) and include:

  • chloroquine
  • atovaquone-proguanil (Malarone®)
  • artemether-lumefantrine (Coartem®)
  • mefloquine (Lariam®)
  • quinine
  • quinidine
  • doxycycline (used in combination with quinine)
  • clindamycin (used in combination with quinine)
  • artesunate (not licensed for use in the United States, but available through the CDC malaria hotline)

In addition, primaquine is active against the dormant parasite liver forms (hypnozoites) and prevents relapses. Primaquine should not be taken by pregnant women or by people who are deficient in G6PD (glucose-6-phosphate dehydrogenase). Patients should not take primaquine until a screening test has excluded G6PD deficiency.

How to treat a patient with malaria depends on:

  • The type (species) of the infecting parasite
  • The area where the infection was acquired and its drug-resistance status
  • The clinical status of the patient
  • Any accompanying illness or condition
  • Pregnancy
  • Drug allergies, or other medications taken by the patient

If you have or suspect you have malaria, you should contact your doctor immediately.

Source: Centers for Disease Control (CDC)