Malaria prophylaxis Flashcards
Questions to ask regarding travel details?
- Go where? Which part of country you going?
- Go how long? When you come back?
- What you do there? Any outdoor activities?
A doctor asks for your advice on how to give doxycycline antimalarial prophylaxis to give to an 25 yo male with NKDA and comorbidities. He is going to Kenya *(high-resistance to chloroquine) flying in 3 days time, and will be back three weeks later)
PO doxycycline 100 mg OD
- Start 1-2 days prior to departure
- Continue for another 4 weeks after departure
How long to avoid pregnancy after finishing a course of mefloquine?
3 months
Can Malarone (atovaquone-proguanil) be used in a 75yo female patient whose CrCL = 29?
No. Malarone contraindicated in CrCL < 30 mL/min
Describe the regimen for mefloquine in malarial prophylaxis
250 mg once weekly
- Start 1 - 2 weeks before departure (ideally 3 weeks)
- Continue for 4 weeks after return
Main concern or side effect of mefloquine
Neuropsychiatric adverse effects
Which of the following malarial prophylaxis agent should be avoided in patients with G6PD?
a) Mefloquine
b) Doxycycline
c) Chloroquine
d) Malarone
e) None of the above
Answer: C (Chloroquine)
How long to avoid pregnancy after completing a course of doxycycline for malaria prophylaxis?
1 week
What is the preferred malaria prophylactic agent for pregnancy?
Chloroquine (can be used in all trimester of pregnancy)
Describe the course of Malarone for malaria prophylaxis
One tablet (250/150 mg A-P) once a day
- Start 1-2 days before departure
- Continue for 7 days after return
Describe the course of chloroquine for malaria prophyalxis
Two 150 mg base (equivalent to 250 mg chloroquine phosphate) weekly
- Start one week before departure
- Continue for 4 weeks after return
Can mefloquine be used in patients who are flying off at a short notice? If yes, describe the regimen and state the disadvantage
Yes
- 250 mg x 3 days before departure as loading dose
- Weekly after that
Disadvantage: more side effects
Dose of mefloquine for a 5 yo child who weighs 25 kg?
125 mg once weekly
Dose of mefloquine for a 10yo child who weighs 46 kg?
250 mg once weekly
Dose of mefloquine for a 2yo child who weighs 8 kg?
4.6 mg/kg, hence about 40 mg once weekly
(< 9kg are dosed by weight, else in incrementals of 62.5 mg)
Anti-malarial drug that interacts with oral contraceptives
Doxycycline. May require other forms of birth control
If a patient who just took mefloquine 15 minutes ago vomited, what should he or she be instructed to do?
Take another dose of mefloquine (cutoff time for this is 30 mintues). If vomiting persists, visit a doctor immediately
If a patient who just took malarone 50 minutes ago vomited, what should he or she be instructed to do?
Take another dose of malarone (cutoff time for this is 60 mintues). If vomiting persists, visit a doctor immediately
Significant side-effects that should be counselled and monitored in patients taking chloroquine?
- Blurred vision (retinopathy)
- Muscle weakness and cramps
A patient taking chloroquine is also taking antacid. What is the counselling point for this patient?
Space them at least 4 hours apart
What can you tell a patient to improve the absorption of malarone?
Take with milk
How long should patients monitor for signs and symptoms of malaria after travelling to a malaria-prevalent country?
1 year
In patients with epilepsy, what are the anti-malarial drugs to avoid?
Chloroquine and mefloquine
What antiepileptic drugs do doxycycline interact with, and hence not recommended to be used together? What is the interaction?
- Carbamazepine
- Phenytoin
- both decreases doxycycline levels by increasing its metabolism
Anti-malarial drugs that are preferred in patients with renal insufficiency
Mefloquine and doxycycline
Anti-malarial drug that is safe in lactating patients
Mefloquine
