It's vital that the information given on this thread is accurate, and to my knowledge what Keith says in this post (35) is correct. Note that drugs for malaria prophylaxis (prevention) are not prescribable on the NHS. Treatment is of course on the NHS ; prophylaxis is not absolute and if the patient has already taken prophylaxis, different drugs will be used.
Obviously we can't give precise recommendations for every member. Take into account : risk, extent of drug resistance, side effects, and patient-related factors ( age, pregnancy, general health such as kidney / liver disease ). Falciparum malaria is particularly dangerous in pregnancy, especially in the last trimester.
The British National Formulary (www.bnf.org) gives advice for UK residents travelling to endemic areas, agreed by malaria specialists, and I have always confirmed with it before posting.
For those requiring long term prophylaxis, Mefloquine is licensed for up to a year ( but has been used for up to 3 years without undue problems) ; Doxocycline can be used for up to 2 years ; Malarone is licensed for up to 28 days, but can be used for up to a year ( possibly longer ) with caution - take specialist advice.