This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug, changing your diet or commencing any course of treatment.
Very important. A change in your diet, medicine, or dosage may be necessary. Promptly consult your doctor or pharmacist.
How the interaction occurs:
Grapefruit juice may increase the amount of primaquine in your blood.
What might happen:
When primaquine is taken with grapefruit juice, the grapefruit juice may cause the primaquine to build up in your body. This increased amount of primaquine can have a greater effect of both desired and undesired effects, including blood disorders and stomach upset.
What you should do about this interaction:
While you are taking this medicine, you should avoid eating grapefruit or drinking grapefruit juice. You may choose an alternative citrus beverage (such as orange juice). In the event that you are instructed by a healthcare professional (e.g., doctor, pharmacist, or dietitian) to eat grapefruit or drink grapefruit juice you should discuss with your doctor the effects of grapefruit on the blood levels of this medicine. These effects can occur even if grapefruit is not consumed at the same time of the primaquine dose. This interaction may occur at any time in your treatment with primaquine if grapefruit or grapefruit juice is consumed.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.Reference:1.Cuong BT, Binh VQ, Dai B, Duy DN, Lovell CM, Rieckmann KH, Edstein MD. Does gender, food or grapefruit juice alter the pharmacokinetics of primaquine in healthy subjects?. Br J Clin Pharmacol 2006 Jun;61(6):682-9.