What is the second line treatment for severe falciparum malaria after IV artesunate?

The second-line treatment for severe falciparum malaria following IV artesunate is indeed intravenous quinine for 5 days, often followed by doxycycline. This approach is taken when the patient does not respond adequately to the first-line treatment or in cases where artesunate is not available. Quinine has a long-established role in the management of malaria and is effective against Plasmodium falciparum, especially in cases of severe illness.

The regimen typically involves starting with IV quinine to ensure quick action in treating the severe infection, followed by a course of doxycycline to help clear the parasite more effectively and prevent relapse. This combination also helps to reduce the potential for resistance, which is a concern with any antimalarial treatment.

Other options in the question, such as oral artemether, IV metronidazole, and oral tetracycline, do not align with the established second-line protocol for severe falciparum malaria. Oral artemether may be used in other contexts but is not typically the next step after IV artesunate. IV metronidazole is more commonly associated with anaerobic infections and does not have efficacy against malaria, while oral tetracycline is not recommended as a standalone treatment for severe cases. Hence, the selection