Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Anemia: Primaquine may cause low levels of red blood cells. If you experience symptoms of reduced red blood cell count (anemia) such as shortness of breath, feeling unusually tired, or pale skin, contact your doctor as soon as possible.
Your doctor will do blood tests regularly to monitor the number of specific types of blood cells, including red blood cells, in your blood.
Heart rhythm: Primaquine can cause changes to the normal rhythm of the heart, including an irregular heartbeat called QT prolongation. QT prolongation is a serious life-threatening condition that can cause fainting, seizures, and sudden death. If you are at risk for heart rhythm problems (e.g., people with heart failure, angina, low potassium or magnesium levels), discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Infection: Primaquine can reduce the number of cells that fight infection in the body (white blood cells). Tell your doctor as soon as possible if you notice signs of an infection, such as fever or chills, severe diarrhea, shortness of breath, prolonged dizziness, headache, stiff neck, weight loss, or listlessness. Your doctor will do blood tests regularly to monitor the number of specific types of blood cells in your blood.
Other medical conditions: If you have a history of hemolytic anemia, glucose-6-phosphate dehydrogenase (G-6_PD) deficiency, nicotinamide adenine dinucleotide (NAD), or methemoglobin reductase deficiency, you may be at higher risk of side effects with primaquine. Inform your doctor if you have been diagnosed with any of these conditions at any point in time.
Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: It is not known if primaquine passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.