Primaquine Phosphate and Tolvaptan

• Generic Name: primaquine
• Dosage Forms: n.a.
• Other Brand Names:

Treatment of malaria caused by Plasmodium vivax or P. ovale. Provides a radical cure to prevent relapse of malaria caused by these Plasmodium. Has only low activity against asexual erythrocytic forms of Plasmodium; a regimen that includes a blood schizonticidal agent (e.g., chloroquine [or hydroxychloroquine]; quinine with doxycycline or tetracycline; mefloquine; fixed-combination of atovaquone and proguanil [atovaquone/proguanil]; fixed combination of artemether and lumefantrine [artemether/lumefantrine]) is always used in conjunction with primaquine for treatment of P. ovale or P. vivax malaria.

Presumptive antirelapse therapy (terminal prophylaxis) in travelers who received a suitable antimalarial for prevention of malaria but are returning from areas where P. vivax or P. ovale is endemic. If primaquine not used for terminal prophylaxis in individuals who may have been exposed to P. ovale or P. vivax malaria, delayed primary attacks or relapse caused by these Plasmodium can occur.

Prevention of malaria (primary prophylaxis). Primaquine may be an option when other recommended antimalarials (choroquine [or hydroxychloroquine], atovaquone/proguanil, doxycycline, mefloquine) cannot be used for primary prophylaxis and is a good choice when travelers will be in areas with high incidence of P. vivax malaria. If primaquine is used for primary prophylaxis, primaquine presumptive antirelapse therapy is not needed.

Assistance with diagnosis or treatment of malaria is available from CDC Malaria Hotline at 770-488-7788 or 855-856-4713 from 9:00 a.m. to 5:00 p.m. Eastern Standard Time or CDC Emergency Operation Center at 770-488-7100 after hours and on weekends and holidays.

Information on risk of malaria in specific countries and mosquito avoidance measures and recommendations regarding whether prevention of malaria is indicated and choice of antimalarials for prevention are available from CDC.

Pneumocystis jirovecii Pneumonia

Treatment of Pneumocystis jirovecii (formerly Pneumocystis carinii) pneumonia (PCP); used in conjunction with clindamycin. Designated an orphan drug by FDA for use in conjunction with clindamycin for treatment of PCP associated with AIDS.

Co-trimoxazole is drug of choice for treatment of mild, moderate, or severe PCP, including PCP in HIV-infected adults, adolescents, and children. CDC, NIH, and IDSA state that a regimen of primaquine and clindamycin is an alternative for treatment of mild, moderate, or severe PCP in HIV-infected adults and adolescents who have had an inadequate response to co-trimoxazole or when co-trimoxazole is contraindicated or not tolerated. Although data not available regarding use in children, CDC, NIH, IDSA, and AAP state that a regimen of primaquine and clindamycin also can be considered an alternative to co-trimoxazole for treatment of PCP in HIV-infected children based on data in adults.

Not recommended for prevention of initial episodes (primary prophylaxis) of PCP in HIV-infected individuals because data insufficient to determine efficacy; not included in recommendations for long-term suppressive or chronic maintenance therapy (secondary prophylaxis) of PCP. Co-trimoxazole is drug of choice for primary and secondary prophylaxis of PCP in HIV-infected adults, adolescents, and children.

• Generic Name: tolvaptan
• Dosage Forms: n.a.
• Other Brand Names: Samsca, Jynarque

This medication guide provides information about the Samsca brand of tolvaptan. Jynarque is another brand of tolvaptan that is not covered in this medication guide.

Tolvaptan (Samsca) is used to treat hyponatremia (low levels of sodium in your blood) in people with heart failure, and certain hormonal imbalances. Tolvaptan improves urine flow without causing the body to lose too much sodium as you urinate.

Samsca may also be used for purposes not listed in this medication guide.