Pediatric prescribers are very often faced with a lack of suitable therapies, particularly oral ones. This represents a major public health problem and necessitates adjustments to dosage or pharmaceutical form using medications marketed for adults, some of which contain excipients that may be harmful to children. This creates risks of dilution errors, administration errors, and the occurrence of adverse effects. Hospital pharmacy technicians are called upon daily to provide appropriate treatment for children. However, although this activity is authorized (Public Health Code, Good Preparation Practices), pharmacokinetic/pharmacodynamic studies on these preparations are only exceptionally carried out. Indeed, only stability studies are required to determine the expiration date of the preparation. Thus, prescribers are left without the necessary information to choose the dosage and administration schedule. Pediatric dosages are extrapolated from those for adults without any certainty of the treatment's effectiveness.

The pediatric hematology-oncology department wanted to include an oral form of nicardipine in its therapeutic arsenal. Nicardipine is a widely used antihypertensive drug for secondary hypertension, particularly that caused by corticosteroid use. This oral form is preferred for its flexibility in dosing, which is based on weight and blood pressure readings. A first formulation was developed in 2017 and subsequently optimized in terms of excipients and raw material availability, leading to a second formulation in 2021. Nicardipine oral solution has been routinely prepared, dispensed, and administered for many years. The lack of bibliographic data concerning the use of nicardipine in a pediatric population prevents us from understanding the pharmacokinetic (PK) parameters, which are nevertheless essential for optimizing the benefit/risk balance of the drug and for individualizing doses. This study aims to optimize the use of this preparation in the management of hypertension in pediatrics and to promote the benefits of this formulation. This study is valuable because it is situated within the context of the routine therapeutic management of a patient in the pediatric hematology-oncology department suffering from hypertension. It therefore does not entail any modification of the child's care.

Inclusion Criteria:

• Patients aged 1 to 15 years, male or female.
• Patients followed in pediatric hematology-oncology.
• Patients with a central venous catheter as part of their initial care and available for blood sampling.
• Patients with a prescription for oral nicardipine (oral solution) whose formulation and/or dosage is/are not compatible with the commercial form of Loxen® 20 mg, requiring preparation.
• Patients requiring oral administration of nicardipine every 8 hours (initial prescription or renewal).
• Patients covered by a social security scheme.
• Parents/guardians informed of the study and not objecting to their child's participation
• For minors old enough to understand: patients who have not objected to the research.

Exclusion Criteria:

• Patient n'ayant pas un schéma d'administration toutes les 8 heures.
• Hypersensibilité à la substance active.
• Antécédent d'allergie à l'un des excipients (polysorbate 80, hypromellose, saccharine sodique, sorbate de potassium, acide citrique, citrate de sodium, saccharose).
• Refus de participation de l'enfant, des parents ou du représentant légal.
• Inclusion de l'enfant dans un autre essai clinique, si des prélèvements sanguins supplémentaires sont également prévus, dans un délai de 7 jours.

Children in pediatric hematology-oncology requiring nicardipine administration as part of their standard care whether or not they are nicardipine-naïve (switching from the intravenous form used for hypertensive emergencies to the oral form, or patients already receiving hospital-prepared nicardipine oral solution at 2 mg/mL)

The data provided will be the property of the sponsor and will be used solely for its own research activities.