MALARIA Flashcards
Bite protection
- Mosquito nets impregnated with permethrin
- Diethyltoluamide (DEET) 20-50% (50% lasts longer protection)
DEET
o Suitable for anyone over 2 months old
o Avoid ingestion - was hands before eating
o Suitable for pregnancy and breastfeeding (wash breast before feeding)
o Apply DEET after sunscreen
DEET reduces SPF of sunscreen - use high SPF lotion
DEET and pregnancy
Suitable for pregnancy and breastfeeding (wash breast before feeding)
DEET and sunscreen
DEET reduces SPF of sunscreen - use high SPF lotion
DEET after sunscreen
Prophylaxis treatment
Malarone
Chloroquine
Proguanil
Mefloquine
Doxycycline
Malarone
1-2 days before travel
1 daily
1 week after travel
Max use: 1 year
Chloroquine
1 week before travel
1 weekly
4 weeks after travel
long term
proguanil
1 week before travel
1 daily
4 weeks after travel
long term
mefloquine
2-3 weeks before travel
1 weekly
4 weeks after travel
Max use: 1 year
Doxycycline
1-2 days before travel
1 daily
4 weeks after travel
max use: 2 yrs
prophylaxis should be continued for 4 weeks after leaving the area, except for the following which should be stopped one week after leaving
atovaquone with proguanil hydrochloride
Illness occurring within 1 year, especially 3 months of return
might still be malaria – see doctor early, mentioning malaria
Proguanil in pregnancy
can no longer be used in malaria prophylaxis in pregnant patients. Only chloroquine now licenced
Pregnancy
- Avoid traveling to malarious regions
- Chloroquine can be given - avoid other medications
Folic acid and antimalarials
give folic acid (dosed as a pregnancy at high risk of neural tube defects) for the length of time that it is used during pregnancy
5mg OD
if a pregnant woman is travelling to high risk areas or there is resistance to other drugs, consider this drug in the 2nd and 3rd trimesters. it can be used in 1st trimester with caution if benefits outweigh risks.
mefloquine
use of doxycycline for prophylaxis during pregnancy
doxy is CI in pregnancy
however it can be used for malaria prophylaxis if other regimens are unsuitable, and if the entire course of doxy can be completed before 15 weeks gestation
doxycycline is contraindicated in pregnancy however it can be used for malaria prophylaxis if other regimens are unsuitable, and if the entire course can be completed before ….
before 15 weeks gestation
this combination should be avoided during pregnancy however it can be used during 2nd and 3rd trimester if no suitable alternative. you will also need to give folate supplementation during the length of time it is used during pregnancy (using 5mg which is the dose for pregnancy at high risk of neural tube defects)
Atovaquone with proguanil hydrochloride
Asplenia
Asplenic patients are at risk of severe malaria
Epilepsy
Avoid chloroquine and mefloquine – reduces seizure threshold
doxycycline can be used for malaria prophylaxis in pt with history of epilepsy. however, it interacts with some anti epileptics and its dose may need adjustment. name and explain some interactions
inducers:carbamazepine, phenytoin, barbiturates
these drugs DECREASE the concentration of doxycycline. adjust dose of doxy
Warfarin
- Begin treatment 2-3 weeks before departure
- INR should be stable before departure
- Measure INR before antimalarials, 7 days after starting and after completing course
- Prolonged stay – check INR regularly
travellers taking warfarin need to begin malaria chemoprophylaxis ….. before departure and their INR needs to be stable before departure
2-3 week before departure
when should warfarin INR be measured for pt taking chemoprophylaxis?
before starting chemoprophylaxis
7 days after starting
after completing course
Mefloquine caution
- History of psychiatric disorders - if these develop = STOP and seek medical
- attention
- History of convulsions
- Reduces seizure threshold
Chloroquine side effects
- History of convulsions
- Can be retinotoxic – eye symptoms
- ototoxicity
Proguanil cautions
- Renal Impairment - reduce dose
in order to use standby emergency treatment appropriately, the traveller should be provided with
Travellers should be provided with written instructions:
Seek urgent medical attention if fever (38°C +) develops 7+ days after arriving in a malarious area
should you use the same drug that was used for chemoprophylaxis for emergency standby treatment
A drug used for chemoprophylaxis should not be considered for standby treatment for the same traveller due to concerns over drug resistance and to minimise drug toxicity.
A patient wants some malaria tablets before he goes away next week. you look at his PMR and see that he is taking takes azithromycin for lyme disease (500mg OD for 17 days). from this information which anti-malarial would you ideally want to avoid and why?
ideally avoid chloroquine because A + C = increased risk of CV events including angina, chest pain and HF and mortality.
chloroquine is associated with ocular toxicity. this is unlikely if the dose of chloroquine phosphate does not exceed ….
4mg/kg daily
chloroquine is …toxic so there is increased risk of …toxicity with drugs e.g.
ototoxic
ototoxicity risk with loop diuretics, aminoglycosides, vincristine vinblastine etc
important side effect of mefloquine and which patients it is contraindicated in
potentially serious neuropsychiatric reactions
common: abnormal dreams, insomnia, anxiety, depression
psychiatric symptoms should be regarded as potentially prodromal for a more serious event
adverse reactions may occur and persist up to several months after discontinuation due to Long half life
avoid for prophylaxis if Hx psychiatric disorders (including depression) or convulsions
a patient needs some anti malarial tabs for prophylaxis. she takes sertraline 100mg daily. she is contraindicated for this drug because…
mefloquine contraindicated for prophylaxis if Hx psychotic disorders including depression
it is associated with potentially serious neuropsychiatric reactions
long half life so can persist up to several months after discontinuation
mefloquine - family of quinine so it has this important interaction with drugs
increased risk of QT prolongation with amiodarone, antipsychotics, dronedarone, fluconazole, erythromycin, methadone, etc
a patient is taking atovaquone with proguanil for prophylaxis of malaria. they develop diarrhoea and vomitting. what does this mean.
caution in diarrhoea or vomiting as reduced absorption
